Prevost XLII-45 Motorhome Owner's Manual
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SECTION 00 : GENERAL INFORMATION
CONTENTS
1. FOREWORD ..................................................................................................................................... 00-2
2. SCHEMATICS................................................................................................................................... 00-2
3. PRECAUTIONS TO BE OBSERVED BEFORE WELDING............................................................. 00-2
4. SAFETY NOTICE.............................................................................................................................. 00-3
4.1 DATA PLATES AND CERTIFICATIONS.................................................................................... 00-3
4.1.1 Engine................................................................................................................................. 00-3
4.1.2 Transmission....................................................................................................................... 00-3
4.1.3 Drive Axle............................................................................................................................ 00-4
4.1.4 Front Axle............................................................................................................................ 00-4
Steering Pump ......................................................................................................... 00-4
4.1.6 Coach
Certification.............................................................................................................. 00-4
4.1.8 DOT
Engine Label............................................................................................................... 00-4
4.1.10 Fuel
Identification Number (VIN).................................................................................... 00-5
5.1 S ELF -L OCKING F ASTENERS .......................................................................................................... 00-8
5.2 R ECOMMENDATIONS F OR R EUSE .................................................................................................. 00-8
5.3 S IX L OBED S OCKET H EAD ............................................................................................................. 00-8
ILLUSTRATIONS
FIGURE 1: DETROIT DIESEL SERIES 60 ............................................................................................... 00-3
FIGURE 2: WORLD TRANSMISSION...................................................................................................... 00-3
FIGURE 3: EATON TRANSMISSION....................................................................................................... 00-3
FIGURE 4: TYPICAL SERIAL & MODEL NUMBERS............................................................................... 00-4
FIGURE 5: TYPICAL SERIAL & MODEL NUMBERS............................................................................... 00-4
FIGURE 6: ISS TYPICAL SERIAL & MODEL NUMBERS ........................................................................ 00-4
FIGURE 7: POWER STEERING PUMP NAMEPLATE ............................................................................ 00-4
FIGURE 8: ENGINE COMPARTMENT .................................................................................................... 00-5
FIGURE 9: VEHICLE I.D. 00-5
FIGURE 10: VEHICLE IDENTIFICATION NUMBER 00-6
FIGURE 11: THREAD NOTATION .......................................................................................................... 00-7
FIGURE 12: BOLT STRENGTH MARKINGS .......................................................................................... 00-7
FIGURE 13: SELF-LOCKING FASTENERS ............................................................................................ 00-8
FIGURE 14: METRIC US STANDARD CONVERSION TABLE ............................................................. 00-9
FIGURE 15: CONVERSION CHART ...................................................................................................... 00-10
00-1
Section 00 : GENERAL INFORMATION
1. FOREWORD
This manual includes procedures for diagnosis, service, maintenance and repair for components of the XL2 series coach or bus shell model listed on the front cover page.
This manual should be kept in a handy place for ready reference by the technician. If properly used, it will meet the needs of the technician and owner.
Information provided in Section 1 through 24 pertains to standard equipment items, systems and components as well as the most commonly used optional equipment and special equipment offered on the coach models covered by this manual.
At the beginning of each section: a Table of
Contents and a list of illustrations give the page number on which each subject begins and where each figure is located.
Coach operating information is provided in a separate Operator's Manual. Audio/Video system operator instructions are also included in a separate manual.
More specific information on engine and transmission operating, maintenance, and overhaul information is contained in the applicable engine or transmission service manual published by the engine or transmission manufacturer. Engine and transmission parts information is contained in the applicable engine or transmission parts catalog published by the engine or transmission manufacturer.
All information, illustrations and specifications contained in this manual are based on the latest product information available at the time of publication approval. The right is reserved to make product changes at any time without notice.
Note : Typical illustrations may be used, therefore minor illustration difference may exist when compared to actual parts or other publications.
Prévost Car occasionally sends Maintenance
Information, Warranty Bulletins, Campaign
Bulletins or other literature to update users with the latest service procedures. They are issued, when required, to supplement or supersede information in this manual. Update sheet should be filled out and bulletins should be filed at the end of their respective section for future reference.
2. SCHEMATICS
Vehicle AIR SCHEMATICS are provided at the end of Section 12, "Brake". SUSPENSION AIR
SCHEMATICS are provided at the end of
Section 16, "Suspension". Moreover,
ELECTRICAL SCHEMATICS are provided in the technical publications box. Refer to those schematics for detailed circuit information or during diagnosis.
PRECAUTIONS TO BE OBSERVED
BEFORE WELDING
Caution: Cut off battery power in main power compartment using battery safety switch.
1. Disconnect “Ground” cables from battery terminals.
Note: Disconnect “Ground” cables only.
2. If welding must be done near the dashboard i.e. steering column, you must disconnect all electronic control modules (radio & control head, HVAC, TTLT cluster Volvo). You must also disconnect alternator module located in front service compartment.
3. Disconnect three wiring harness connectors from ECM (Electronic Control Module). The
ECM is mounted on the starter side of the engine.
4. For vehicles equipped with an Allison automatic transmission, disconnect three wiring harness connectors from ECU
(Electronic Control Unit). The ECU is located in front service compartment.
5. For vehicles equipped with ABS (Anti-Lock
Brake System), disconnect wiring harness connectors from ABS Electronic Control Unit.
The ABS Electronic Control Unit is located in front service compartment.
6. Cover electronic control components and wiring to protect from hot sparks, etc.
7. Do not connect welding cables to electronic control components.
8. Do the appropriate welding on vehicle.
Caution: Position welding machine ground clamp as close as possible to the work.
9. When welding is complete, reconnect ECM,
ECU, ABS electronic control units, etc.
10. Terminate by reconnecting “Ground” cables to battery terminals.
00-2
Section 00 : GENERAL INFORMATION
4. SAFETY NOTICE
This maintenance manual has been prepared in order to assist skilled mechanics in the efficient repair and maintenance of PRÉVOST vehicles.
This manual covers only the procedures as of manufacturing date.
Safety features may be impaired if other than genuine PRÉVOST parts are installed.
Torque wrench tightening specifications must be strictly observed. Locking devices must be installed or replaced by new ones, where specified. If the efficiency of a locking device is impaired, It must be replaced.
This manual emphasizes particular information outlined by the wording and symbols:
Warning : Identifies an instruction which, if not followed, could cause personal injuries.
Caution : Outlined an instruction which, if not followed, could severely damage vehicle components.
Note
:
Indicates supplementary information needed to fully complete an instruction.
Although, the mere reading of such information does not eliminate the hazard, understanding of the information will promote its correct use.
4.1 DATA PLATES AND CERTIFICATIONS
Delay and confusion can be avoided by placing the complete vehicle identification number of the coach and the serial numbers of the engine on parts orders and correspondence. Also, the transmission, axles, power steering pump chassis and other major components are identified by serial numbers.
4.1.1 Engine
The engine serial and model number are stamped on the cylinder block (as viewed from the flywheel end) on the left side just below the fire deck and above the cast-in Detroit Diesel logo (Fig. 1).
FIGURE 1 : DETROIT DIESEL SERIES 60
01054
In addition, option plates made of laminated paper are located on the rocker cover (starter side). The engine serial and model number and a list of the optional engine equipment is written on the option plate. Refer to this information when ordering replacement parts (Fig. 1).
4.1.2 Transmission
The transmission identification plate may be located on the right-rear side of the transmission.
The identification plate shows the transmission serial number, part number (assembly number), and model number. Use all three numbers when ordering parts.
FIGURE 2: WORLD TRANSMISSION
07019
FIGURE 3: EATON TRANSMISSION 07062
00-3
Section 00 : GENERAL INFORMATION
4.1.3 Drive Axle
FIGURE 4: TYPICAL SERIAL & MODEL NUMBERS
11019
4.1.4 Front Axle
FIGURE 5: TYPICAL SERIAL & MODEL NUMBERS
10024
FIGURE 6: ISS TYPICAL SERIAL & MODEL NUMBERS
4.1.5 Power Steering Pump
Power steering pump serial number is located on a tag on the pump (Fig. 7). The pump is mounted on the engine beside the crankshaft pulley.
FIGURE 7 : POWER STEERING PUMP NAMEPLATE
00001
4.1.6 Coach Final Record
The Coach Final Record is a record of all data pertaining to the assembly of the coach. This record is included in the technical publication package supplied with the coach. Retain this record in the company records office for reference and safe-keeping.
4.1.7 Safety Certification
Coach components meet specifications and standards as follows:
- Material and parts conform to ASTM and/or
SAE standards in effect at the time of manufacture.
- All factory-installed interior materials meet
FMVSS 302 for fire resistance.
- Certified according to Provincial, State and
Federal Safety standards (Canadian and US)
BMCSS, FMVSS, and CMVSS.
Other applicable certification labels are affixed to the component.
4.1.8 DOT Certification Label
This certifies that coaches manufactured by
Prevost Car Inc., comply with all Federal Motor
Vehicle Safety Standards at the time of manufacture. The DOT Certification label is affixed on the wall, behind the driver's seat.
4.1.9 EPA Engine Label
The exhaust emission certification label affixed to the rear junction box certifies that the engine conforms to federal and any state exhaust emission regulations (Fig. 8). It gives the operating conditions under which certification was made.
00-4
FIGURE 8 : ENGINE COMPARTMENT 01011
4.1.10 Fuel Tank Label
The fuel tank label is molded on the side of the fuel tank. To read this label, unscrew the fuel tank access panel nuts located at the left in the condenser compartment.
4.1.11 Vehicle Identification Number (VIN)
The seventeen digit vehicle identification number
(VIN) is located on a plate (Fig. 9 & 10) located on the windshield frame pillar (driver's side). The
VIN is visible from the outside of the coach.
Make sure the correct vehicle identification number is given when ordering replacement parts. Using the VIN when ordering parts will facilitate processing.
FIGURE 9 : VEHICLE I.D.
18309
Note: Record the VIN in the coach documentation and keep with company records.
The VIN will normally be used for vehicle registration and for obtaining vehicle insurance coverage.
00-5
Section 00 : GENERAL INFORMATION
Section 00 : GENERAL INFORMATION
FIGURE 10 : VEHICLE IDENTIFICATION NUMBER VIN1
YEAR CODE YEAR CODE
1996
1997
T
V
1999
2000
X
Y
1998 W 2001 Z
00-6
5. FASTENER STRENGTH IDENTIFICATION
Most commonly used metric fastener strength property classes are 9.8 and 10.9 with the class identification embossed on the head of each bolt. Customary (inch) strength classes range from grade 2 to 8 with radial line identification embossed on each bolt head actual grade (i.e., a grade 7 bolt will have 5 embossed radial lines on the bolt head). Some metric nuts will be marked with single digit strength identification numbers on the nut face. Fig. 12 shows the different strength markings. When replacing metric
Section 00 : GENERAL INFORMATION fasteners, be careful to use fasteners of the same or greater strength than the original fasteners (the same number marking or higher).
It is also important to select replacement fasteners of the correct size. Correct replacement fasteners are available through the parts division. Some metric fasteners available in after-market parts sources were designed to metric standards of countries other the United
States and may be of a lower strength, may not have the numbered head marking system, and may be of a different thread pitch.
FIGURE 11 : THREAD NOTATION
00002
FIGURE 12: BOLT STRENGTH MARKINGS
The metric fasteners used on the coach are designed to new standards and may not yet be manufactured by some non-domestic fastener suppliers. In general, except for special applications, the common sizes and pitches are :
• M 8 X 1.25;
00-7
• M 10 X 1.5;
• M 12 X 1.75;
• M 14 X 2;
00003
Section 00 : GENERAL INFORMATION
5.1 SELF-LOCKING FASTENERS
A self-locking fastener is designed with an interference fit between the nut and bolt threads.
This is most often accomplished by distortion of the top thread of an all-metal nut or bolt or by using a nylon patch on the threads. A nylon insert or the use of adhesives may also be used as a method of interference between nut and bolt threads (Fig. 13).
5.2 RECOMMENDATIONS FOR REUSE
Clean, unrusted self-locking fasteners may be reused as follows : a) Clean dirt and other foreign matter from the fastener; b) Inspect the fastener to ensure there is no crack, elongation, or other sign of fatigue or overtightening. If there is any doubt, replace with a new self-locking fastener of equal or greater strength; c) Assemble parts and hand start fastener; d) Observe that, before the fastener seats, it develops torque per the chart in table two. If there is any doubt, replace with a new selflocking fastener of equal or greater strength; e) Tighten the fastener to the torque specified in the applicable section of this manual;
Fasteners which are rusty or damaged should be replaced with new ones of equal or greater strength.
FIGURE 13 : SELF-LOCKING FASTENERS 00004
METRIC
NUTS AND
SELF-LOCKING FASTENER TORQUE CHART
N•m
6 & 6.3
0.4
8
0.8
10 12 14 16 20
1.4 2.2 3.0 4.2 7.0
ADHESIVE OR NYLON N•m 0.4 0.6 1.2 1.6 2.4 3.4 5.6
US STANDARD .250 .312 .375 .437 .500 .562 .625 .750
NUTS N•m 0.4 0.6 1.4 1.8 2.4 3.2 4.2 6.2
ADHESIVE OR NYLON N•m 0.4 0.6 1.0 1.4 1.8 2.6 3.4 5.2
5.3 SIX LOBED SOCKET HEAD
Six lobed socket head (Torx) fasteners are used in some applications on vehicles covered in this manual. The tools designed for these fasteners are available commercially. However, in some cases, if the correct tool is not available, a hex socket head wrench may be used.
00-8
Section 00 : GENERAL INFORMATION
FIGURE 14: METRIC - US STANDARD CONVERSION TABLE
00-9
00005
Section 00 : General Information
FIGURE 15: CONVERSION CHART
00-10
00006
SECTION 01: ENGINE
CONTENTS
1. ENGINE............................................................................................................................................. 01-3
2. ENGINE-MOUNTED COMPONENTS .............................................................................................. 01-3
2.1 E LECTRONIC C ONTROL M ODULE ................................................................................................... 01-4
2.2 E LECTRONIC U NIT I NJECTOR ......................................................................................................... 01-4
3.1 T IMING R EFERENCE S ENSOR ........................................................................................................ 01-5
3.2 T URBO B OOST P RESSURE S ENSOR ............................................................................................... 01-5
3.3 C OOLANT T EMPERATURE S ENSOR ................................................................................................ 01-6
3.4 F UEL T EMPERATURE S ENSOR ....................................................................................................... 01-6
3.5 A IR T EMPERATURE S ENSOR .......................................................................................................... 01-6
3.6 O IL P RESSURE S ENSOR ............................................................................................................... 01-6
3.7 O IL T EMPERATURE S ENSOR .......................................................................................................... 01-6
4. ENGINE-RELATED COMPONENTS ............................................................................................... 01-6
4.1 C OOLANT L EVEL S YSTEM (CLS) ................................................................................................... 01-6
4.2 E LECTRONIC F OOT P EDAL A SSEMBLY (EFPA) & T HROTTLE P OSITION S ENSOR .............................. 01-7
4.3 C RUISE C ONTROL S WITCHES (CCS) ............................................................................................. 01-7
4.4 D IAGNOSTIC S YSTEM A CCESSORIES (DSA)................................................................................... 01-7
Engine Telltale Light ................................................................................................ 01-7
4.4.2 Stop
4.4.3 Stop Override Switch.............................................................................................. 01-8
4.4.4 Diagnostic Data Link (DDL) Connectors............................................................................. 01-8
5. DDEC IV DIAGNOSTIC CODES ...................................................................................................... 01-8
5.1 READING DIAGNOSTIC CODES FLASHING LIGHT METHOD : ............................................................... 01-8
7. ENGINE OIL AND FILTER CHANGE ............................................................................................ 01-11
9. POWER PLANT ASSEMBLY REMOVAL...................................................................................... 01-12
10. POWER PLANT ASSY. INSTALLATION................................................................................... 01-14
11.1 XL2-45 COACHES AND MOTORHOMES .......................................................................................... 01-15
11.2 XL2-40 COACHES ....................................................................................................................... 01-15
12. JAKE BRAKE ............................................................................................................................. 01-16
13. ENGINE MOUNTS ...................................................................................................................... 01-16
15. SPECIFICATIONS....................................................................................................................... 01-18
01-1
Section 01: ENGINE
ILLUSTRATIONS
FIGURE 1: DETROIT DIESEL SERIES 60 ENGINE (TYPICAL) ............................................................. 01-3
FIGURE 2: ELECTRONIC CONTROL MODULE (ECM) .......................................................................... 01-4
FIGURE 3: UNIT INJECTOR CROSS SECTION ..................................................................................... 01-4
FIGURE 4: SRS LOCATION .................................................................................................................... 01-5
FIGURE 5: BULL GEAR ........................................................................................................................... 01-5
FIGURE 6: TIMING GEAR........................................................................................................................ 01-5
FIGURE 7: TURBO BOOST PRESSURE SENSOR ................................................................................ 01-5
FIGURE 8: FUEL TEMPERATURE SENSOR ......................................................................................... 01-6
FIGURE 9: ENGINE OPS AND OTS ........................................................................................................ 01-6
FIGURE 10: ELECTRONIC FOOT PEDAL ASSEMBLY .......................................................................... 01-7
FIGURE 11: ENGINE OIL LEVEL DIPSTICK ......................................................................................... 01-10
FIGURE 12: OIL RESERVE TANK ......................................................................................................... 01-11
FIGURE 13: ENGINE DRAIN PLUG AND OIL FILTERS ........................................................................ 01-11
FIGURE 14: BELT TENSIONER VALVE ................................................................................................ 01-12
FIGURE 15: ELECTRIC FAN-CLUTCH CONNECTOR ......................................................................... 01-13
FIGURE 16: ENGINE COMPARTMENT ................................................................................................ 01-14
FIGURE 17: RUBBER DAMPER TOLERANCE .................................................................................... 01-15
FIGURE 18: POWER PLANT CRADLE INSTALLATION ...................................................................... 01-16
01-2
1. ENGINE
This vehicle is powered by a 6-cylinder, fourcycle, Detroit Diesel series 60 engine equipped with an electronic control system (DDEC IV).
One engine displacement is used in the Series
60 engines: 12.7 liters. Summary information on the Electronic Control System is given in this section.
Complete maintenance and repair information on the engine will be found in the current DDEC IV
Service Manual #6SE483. This maintenance manual covers engine accessories, controls and related components.
Procedures for engine removal and installation are given at the end of this section. The DDEC system is self-diagnostic. It can identify faulty components and other engine-related problems by providing the technician with a diagnostic code.
Section 01: ENGINE
Refer to DDEC Troubleshooting Guide #6SE492 published by Detroit Diesel for more complete information on diagnosis of components and system problems.
DDEC IV ( D etroit D iesel E lectronic C ontrol) controls the timing and quantity of fuel injected by the electronic unit injectors (EUI). The system also monitors several engine functions using electrical sensors, which send electrical signals to the Electronic Control Module (ECM). The
ECM computes the electrical signals and determines the correct fuel output and timing for optimum power, fuel economy and emissions.
The ECM also has the ability to display warnings or shut down the engine completely (depending on option selection) in the event of damaging engine conditions, such as low oil pressure, low coolant level, or high oil temperature.
Two categories divide system components: engine-mounted components and engine-related components.
2. ENGINE-MOUNTED COMPONENTS
FIGURE 1: DETROIT DIESEL SERIES 60 ENGINE (TYPICAL)
Engine-mounted components are as follows:
• Electronic Control Module
• Electronic Unit Injector
• Synchronous Reference Sensor
• Timing Reference Sensor
• Turbo Boost Pressure Sensor
• Coolant Temperature Sensor
• Fuel Temperature Sensor
• Air Temperature Sensor
• Oil Pressure Sensor
• Oil Temperature Sensor
01-3
01015B
Section 01: ENGINE
2.1 ELECTRONIC CONTROL MODULE
The Electronic Control Module is mounted, on
2).
Considered the "Brain" of the DDEC IV system, it provides overall monitoring and control of the engine. It does so by comparing input data from the various sensors to a set of calibration data stored in the EEPROM ( E lectrically E rasable,
P rogrammable, R eadO nly M emory) within the
Electronic Control Module. After comparing the input data with the calibration data, the ECM sends high-current command pulses to the
Electronic Unit Injectors (EUI) to initiate fuel injection. The ECM also receives feedback regarding the start and end of injection for a given cylinder. The EEPROM within the
Electronic Control Module is factory programmed by Detroit Diesel. Reprogramming must be done at a Detroit Diesel authorized service center.
However, some changes may be performed to the cruise control and road speed limiter using a diagnostic data reader (see paragraph "DDEC IV
Diagnostic Codes" in this section).
• Atomizes the fuel for mixing with the air in the combustion chamber;
• Permits continuous fuel flow for component cooling .
FIGURE 2: ELECTRONIC CONTROL MODULE (ECM)
01064
2.2 ELECTRONIC UNIT INJECTOR
The Electronic Unit Injector (EUI) is a compact device that injects diesel fuel directly into the combustion chamber (Fig. 3). The amount of fuel injected and injection timing is determined by the
Electronic Control Module (ECM). The ECM sends a command pulse, which activates the injector solenoid. The EUI performs four functions:
• Creates the high-fuel pressure required for efficient injection;
• Meters and injects the exact amount of fuel required to handle the load;
FIGURE 3: UNIT INJECTOR CROSS SECTION
01019
3. SYNCHRONOUS REFERENCE SENSOR
The Synchronous Reference Sensor (SRS) is an electronic component, mounted to the rear of the gear case (Fig. 4). The SRS senses a raised metal pin on the rear of the bull gear and sends a signal to the ECM via a black connector wire.
The SRS sensor extends through a hole in the gear case. It is positioned near the rear of the bull gear. A bolt, inserted through a hole in the
SRS bracket, secures the SRS assembly to the gear case.
01-4
Section 01: ENGINE of evenly spaced special teeth on the timing wheel. A tooth passes by the TRS as each cylinder crank pin reaches 10 before Top-
Dead-Center.
The ECM uses these signals to determine injector solenoid operation time. The TRS is nonserviceable and must be replaced as a unit. No adjustment is required.
FIGURE 4: SRS LOCATION
01020
FIGURE 5: BULL GEAR
01021
The bull gear pin passes by the SRS as piston number one crank pin reaches 45 before Top-
Dead-Center. The ECM uses this information to determine engine speed.
The SRS is non-serviceable and must be replaced as a unit. No adjustment is required.
3.1 TIMING REFERENCE SENSOR
The Timing Reference Sensor (TRS) is an electronic component mounted on the left side of the gear case (right side of coach), near the crankshaft centerline. The TRS is positioned near the timing wheel gear teeth and extends through an opening in the gear case. A bolt, inserted through a hole in the TRS bracket, secures the TRS assembly to the gear case. The
TRS connector is gray. The TRS sends a signal to the ECM, this signal is generated by a series
01-5
FIGURE 6: TIMING GEAR
01022
3.2 TURBO BOOST PRESSURE SENSOR
Two bolts mount the Turbo Boost Pressure
Sensor to the intake manifold. A rubber O-ring seals the sensor to the manifold (Fig. 7). This device is a pressure sensor that sends an electrical signal to the ECM. The ECM uses this information to compute the volume of air entering the engine. Turbo boost sensor information regulates fuel supply to control engine exhaust.
The turbo boost pressure sensor is nonserviceable and must be replaced as an assembly. No adjustment is required.
FIGURE 7 : TURBO BOOST PRESSURE SENSOR 01023
Section 01: ENGINE
3.3 COOLANT TEMPERATURE SENSOR
The coolant temperature sensor is mounted on the engine's radiator side (turbo side). The sensor helps protect the engine against overheating by sensing coolant temperature.
3.4 FUEL TEMPERATURE SENSOR
The Fuel Temperature Sensor (FTS) is installed on the secondary fuel filter (Fig. 8).
The FTS sends an electrical signal to the ECM indicating fuel inlet temperature. The ECM uses this information to calculate fuel consumption.
The FTS is non-serviceable and must be replaced as a unit. No adjustment is required.
FUEL TEMPERATURE SENSOR
FIGURE 8: FUEL TEMPERATURE SENSOR 01024
3.5 AIR TEMPERATURE SENSOR
The Air Temperature Sensor (Fig. 1) located on the engine (starter side) near the intake manifold provides input data to vary hot idle speed and injection timing. This helps to improve cold starts and reduces white exhaust smoke.
3.6 OIL PRESSURE SENSOR
The Oil Pressure Sensor (OPS) is installed in the main engine-oil gallery. A typical location is the left rear corner of the cylinder block (Fig. 9). The
OPS sends an electrical signal to the ECM indicating the engine oil pressure at any given speed. A low oil pressure signal exceeding seven seconds is used by the ECM to begin the stop engine or warning function. The OPS is non-serviceable and must be replaced as a unit.
No adjustment is required.
OIL
PRESSURE
SENSOR
01-6
OIL TEMPERATURE SENSOR
FIGURE 9: ENGINE OPS AND OTS
01025
3.7 OIL TEMPERATURE SENSOR
The Oil Temperature Sensor (OTS) is installed on the main engine-oil gallery. A typical location is the left rear corner of the cylinder block as shown in Figure 9. The OTS sends an electrical signal to the ECM indicating engine oil temperature. The ECM uses this information to modify engine speed for better cold weather starts and faster warm-ups. Oil temperatures exceeding engine specifications for two seconds or more will illuminate the Check Engine Light.
The OTS is non-serviceable and must be replaced as a unit. No adjustment is required.
4. ENGINE-RELATED COMPONENTS
Engine-related components include:
• Coolant Level System (CLS)
• Electronic Foot Pedal Assembly (EFPA) and
Throttle Position Sensor
• Cruise Control Switch (CCS)
• Diagnostic System Accessories (DSA)
4.1 COOLANT LEVEL SYSTEM (CLS)
The coolant level system consists of a conductivity probe mounted in the surge tank and an electronic interface module located inside the rear junction box. Coolant level is determined by the change in impedance of the probe and its brass mount when immersed in coolant. The electronic device in the module conditions the signal to levels compatible with DDEC. A low coolant level will trigger the engine warning functions.
The probe and electronic interface module are non-serviceable items and should be replaced
as units, if found defective. No adjustment is required.
4.2 ELECTRONIC FOOT PEDAL ASSEMBLY
(EFPA) & THROTTLE POSITION SENSOR
The Electronic Foot Pedal Assembly (EFPA) connects the accelerator pedal to a Throttle
Position Sensor (TPS). The (TPS) is a device, which sends an electrical signal to the Electronic
Control Module (ECM). The TPS signal varies in voltage depending on how far the pedal is depressed. The system is installed in the space normally occupied by a mechanical foot pedal.
The (EFPA) has maximum and minimum stops that are built into the unit during manufacturing
(Fig. 10). The (TPS) converts the operator's foot pedal input into a signal for the ECM. The
(EFPA) is shown in Figure 10.
When installed by the equipment manufacturer, the TPS should not require adjustment. If the
TPS is suspected of being misadjusted, confirm that the sensor is installed in accordance with the manufacturer's specifications. It is recommended that the idle count be at 50 or higher with a full throttle count of up to 200.
The TPS is self-calibrating and therefore has no optimum closed throttle or wide open throttle count value. If the counts are within the 50 to
200 range, the sensor is properly set.
FIGURE 10: ELECTRONIC FOOT PEDAL ASSEMBLY
01026
Monitor the (TPS) at the controls as you move it through its full stroke. Be sure there is no misalignment or obstruction preventing the smooth movement of the TPS through the full stroke. Using a diagnostic data reader, check that the idle and full throttle position counts do not fall within the error zones. The error zones occur when the idle position is less than 14 counts, or when the full throttle position is more
01-7
Section 01: ENGINE than 233 counts. Should these conditions occur, the ECU will signal diagnostic codes of 21-12 for idle error and 21-23 for wide-open throttle error.
4.3 CRUISE CONTROL SWITCHES (CCS)
The four cruise control switches are located in the driver's area on the L.H. side control panel.
1. Cruise: This is the main switch that actuates the ECM memory in order to use the speedregulating mode.
2. Set: This switch is used to set the cruise control speed or to decrease the set speed by 2 MPH at each application.
Note
:
Cruise control system will not accept speed settings, nor will the "Resume" switch operate below 20 mph (32 km/h) and the engine speed must be above 1100 RPM.
3. Resume: Each time this switch is actuated, the speed will be increased by 2 mph (3,5 km/h). This switch allows the driver return to the last regulated speed following a brake or
"DECEL" switch application.
Note : On-off switch must be in the "ON" position in order to return to the last regulated speed.
4. DECEL: Will cancel the cruise temporarily and let the vehicle coast. Set speed is still in memory for resume.
For additional information, see the "Operator's
Manual" or the "Owner's Manual".
4.4 DIAGNOSTIC SYSTEM ACCESSORIES
(DSA)
The DDEC IV engine Diagnostic System
Accessories include the following:
• Check Engine telltale light;
• Stop Engine telltale light;
• Stop Engine Override switch;
• Diagnostic Data Link (DDL) connectors.
4.4.1 Check Engine Telltale Light
The Check Engine telltale, mounted on the telltale light panel indicates that a problem has been detected and that a code has been stored in the ECM memory. This light also has a 5second bulb check when the ignition is first turned on. The Check Engine telltale illuminates when the temperature at coolant sensors exceeds 217 ° F (103 ° C) and the temperature at oil sensors exceeds 260°F (127°C). When
Section 01: ENGINE sensors reach those temperatures, DDEC starts to decrease engine power linearly.
4.4.2 Stop Engine Telltale Light
This light, also mounted on the telltale light panel, illuminates to indicate that a major engine problem is occurring (with the exception of a 5second bulb check when the ignition is first turned on). The Stop Engine Light illuminates when the temperature at coolant sensors exceeds 222°F (106°C) and the temperature at oil sensors exceeds 239°F (115°C). When sensors detect such temperatures, DDEC shuts the engine down after a 30 seconds grace period. This 30-second delay may be extended another 30 seconds (if absolutely necessary) by using the STOP ENGINE OVERRIDE switch.
Note : Once engine is stopped, it can not be restarted until the malfunction is corrected.
4.4.3 Stop Engine Override Switch
This switch, mounted on the dashboard, may be used to extend the 30-second delay period before engine shutdown when the Stop engine telltale light is illuminated. This switch can be repeatedly depressed in order to move the vehicle out of traffic.
Note : The stop engine override switch will be operative only if it has been depressed before the end of the 30 second delay period.
Caution: The OVERRIDE switch must be used only in emergency cases, such as to move the vehicle out of traffic. Excessive use of this switch can cause serious damage to the engine.
This switch is also used for DDEC diagnostic code requests. Press this switch with the engine at idle or off but with the ignition in the "ON" position and active codes will be flashed on the
CHECK ENGINE and STOP ENGINE telltale lights alternately. Refer to “DDEC IV
DIAGNOSTIC CODES” in this section for more information.
4.4.4 Diagnostic Data Link (DDL) Connectors
A connector is mounted on the L.H. footwell wall.
Another connector is located in the rear electric compartment. They allow the connection of the
DDEC
Code
Number
(Flashed)
DESCRIPTION
Diagnostic Data Reader (DDR) to read the codes or to access pertinent data on the condition of the engine. This enables a more complete analysis of any defect found in the
DDEC system operation. For more information, see Detroit Diesel Troubleshooting Guide
#6SE492.
5. DDEC IV DIAGNOSTIC CODES
5.1 READING DIAGNOSTIC CODES -
FLASHING LIGHT METHOD:
DDEC IV makes use of two types of codes:
Active and inactive. The difference between the two types of codes is as follows:
Active Codes: Codes that are currently keeping the Check Engine or Stop Engine telltale light illuminated. Active codes are flashed via the
Stop Engine Light when checked with the stopengine-override switch.
Inactive Codes: These are all the codes logged in the ECM (whether or not they are currently turning on the Stop or Check Engine Light).
Inactive codes are flashed via the Check Engine telltale light when checked with the stop-engineoverride switch. In most instances, only the DDR can provide the information necessary for a quick diagnosis of the problem. If you just need to read out codes, however, and do not have a
DDR available, the following procedure will let you read out codes. Make sure the rear-starting switch (located in the engine compartment) is in the normal position. With the ignition ON, the engine idling or engine shut-off, momentarily depress the Stop Engine Override switch. Active codes will be flashed on the stop engine telltale, followed by the inactive codes being flashed on the check-engine telltale panel. The cycle repeats itself until the operator depresses the stop engine override switch again. A code "43" consists of four flashes, followed by a short pause, then three flashes in quick succession.
Refer to DDEC Troubleshooting Manual 6SE497 for more information and SAE codes.
Note : Active codes are flashed in ascending numerical flash code order. Inactive codes are flashed in most recent to least recent order.
Note : Fault codes can only be cleared using the
DDR.
DDEC
Code
Number
(Flashed)
DESCRIPTION
01-8
Section 01: ENGINE
DDEC
Code
Number
(Flashed)
11
13
DESCRIPTION
Variable speed governor sensor input voltage low
Coolant level sensor input voltage low
DDEC
Code
Number
(Flashed)
12
DESCRIPTION
Variable speed governor sensor input voltage high
14 Oil, coolant or intercooler temperature sensor input voltage high
16 Coolant level sensor input voltage high
15 Oil, coolant or intercooler temperature sensor input voltage low
17
21
Bypass or throttle valve position sensor input voltage high
TPS input voltage high
23 Fuel temperature sensor input voltage high
25 No active codes
27
31
33
35
37
41
43
45
47
Air inlet or intake air temperature sensor input voltage high
Auxiliary high side output open circuit or short to ground
Turbo boost pressure sensor input voltage high
Oil pressure sensor input voltage high
Fuel pressure sensor input voltage high
Too many SRS (missing TRS)
Coolant level low
18
32
34
Bypass or throttle valve position sensor input voltage low
TPS input voltage low 22
24 Fuel temperature sensor input voltage low
26 Auxiliary shutdown #1 or #2, input active
28 Air inlet or intake air temperature sensor input voltage low
Check Engine Light or Stop Engine
Light short to battery (+) or open circuit
Turbo boost pressure sensor input voltage low
36
38
42
44
Oil pressure sensor input voltage low
Fuel pressure sensor input voltage low
Too few SRS (missing SRS)
46
48
Oil, coolant, intercooler or intake air temperature high
ECM battery voltage low
Fuel or air inlet pressure low
52
54
56
58
Oil pressure low
Fuel, air inlet or turbo boost pressure high
ECM A/D conversion fault
Vehicle speed sensor fault
J1587 data link fault
Torque overload
53
55
57
61
ECM non volatile memory fault
J1939 data link fault
J1922 data link fault
Injector response time long
01-9
Section 01: ENGINE
DDEC
Code
Number
(Flashed)
62
64
DESCRIPTION
Auxiliary output short to battery (+) or open circuit or mechanical fault
Turbo speed sensor input fault
Engine knock sensor input fault
DDEC
Code
Number
(Flashed)
63
65
67
DESCRIPTION
PWM drive short to battery (+) or open circuit
Throttle valve position input fault
66
68 TPS idle validation switch open circuit or short to ground
72 Vehicle
74 Optimized idle safety loop short to ground
76 Engine overspeed with engine brake
81 Oil level, crankcase pressure, dual fuel BOI or exhaust temperature voltage high
83 Oil level, crankcase pressure, exhaust temperature or external pump pressure high
85 Engine
71
73
75
77
82
84
Coolant or air inlet pressure sensor input voltage fault
Injector response time short
Gas valve position input fault or
ESS fault
ECM battery voltage high
Fuel temperature high
Oil level, crankcase pressure, dual fuel BOI or exhaust temperature voltage low
Oil level low or crankcase pressure low
86 External pump or barometer pressure sensor input voltage high
88 Coolant pressure low 87 External pump or barometer pressure sensor input voltage low
TABLE X-X: FLASH CODES AND DESCRIPTION
6. ENGINE OIL LEVEL
Check the oil level daily with the engine stopped.
If the engine has just been stopped and is warm, wait at least 10 minutes to allow the oil to drain back to the oil pan before checking. Wipe the dipstick clean then check oil level. The level should always be within the safe range on the dipstick (Fig. 11). Add the proper grade of oil to maintain the correct level on the dipstick. All diesel engines are designed to consume some oil, so a periodic addition of oil is normal.
Warning : Touching a hot engine can cause serious burns.
Caution : Do not overfill. Oil may be blown out through the crankcase breather if the crankcase is overfilled.
Caution: Clean end of tube before removing the dipstick to prevent oil contamination.
FIGURE 11: ENGINE OIL LEVEL DIPSTICK
01027
01-10
Caution: If the oil level is constantly above normal and excess lube oil has not been added to the crankcase, consult with an authorized
Detroit Diesel service outlet for the cause. Fuel or coolant dilution of lube oil can result in serious engine damage.
The vehicle may be provided with an oil reserve tank in the engine compartment. To adjust oil level, open the oil reserve tank drain valve and allow oil to discharge into the engine until the
"Full" mark on the dipstick is reached then close the valve. Check oil reserve tank level and pour oil in the reserve tank if necessary (Fig. 12).
Section 01: ENGINE
Warning : Hot engine oil can cause serious burns. Wear coveralls with sleeves pulled down and gloves to protect hands.
2. Reinstall the drain plug.
FIGURE 12: OIL RESERVE TANK
01063
7. ENGINE OIL AND FILTER CHANGE
Both the oil and filter should be changed every
12,500 miles (20,000-km) or once a year, whichever comes first. However, changes that are more frequent may be required when the engine is subject to high levels of contamination and/or overheating. Change intervals may be decreased or gradually increased with experience on specific lubricants until the most practical service condition has been established.
Always refer to the lubricant manufacturer's recommendations (analysis of drained oil can be helpful).
Caution
:
Do not use solvents to dilute the engine oil when draining. Dilution of fresh oil can occur which may be detrimental to the engine.
Change engine oil with the vehicle on a flat and level surface and with the parking brake applied.
It is best to drain the oil when the engine is still warm.
1. From under the vehicle, remove the engine drain plug on the oil pan. Allow oil to drain
(Fig. 13).
FIGURE 13: ENGINE DRAIN PLUG AND OIL FILTERS 01029
3. Remove the spin-on filter cartridge using a ½" drive socket wrench and extension.
4. Dispose of the used oil and filter in an environmentally responsible manner in accordance with state and/or federal (EPA) recommendations.
5. Clean the filter adapter with a clean rag.
6. Lightly coat the filter gasket (seal) with clean engine oil.
7. Install the new filter on the adapter and tighten manually until the gasket touches the mounting adapter head. Tighten full-flow filters an additional two-thirds of a turn manually.
Then, manually tighten bypass filter one full turn.
Caution: Overtightening may distort or crack the filter adapter.
8. Remove the engine-oil filler cap and pour oil in the engine until it reaches the "FULL" mark on the dipstick (Fig. 11).
9. Start and run the engine for a short period and check for leaks. After any leaks have been corrected, stop the engine long enough for oil from various parts of the engine to drain back to the crankcase (approximately 20 minutes).
10. Add oil as required to bring the level within the safe range on the dipstick (Fig. 11).
01-11
Section 01: ENGINE
8. RECOMMENDED ENGINE OIL TYPE
To provide maximum engine life, lubricants shall meet the following specifications: SAE Viscosity
Grade: 15W-40 API Classification: CH-4
Note: Monograde oils should not be used in these engines regardless of API Service
Classification.
Note: The use of supplemental oil additives is discouraged from use in Detroit Diesel Engines.
Synthetic oils Synthetic oils may be used in
Detroit Diesel engines provided they are APIlicensed and meet the performance and chemical requirements of non-synthetic oils outlined previously. Synthetic oils do not permit extension of recommended oil drain intervals.
Lubricant Selection World Wide Oils meeting
API CD or CC specifications may be used if they also meet military specification MIL-L-2104 D or
E. Oils which meet European CCMC D4 specifications may also be used.
Modification of drain interval may be necessary, depending on fuel quality. Contact Detroit Diesel
Corporation for further guidance.
9. POWER PLANT ASSEMBLY REMOVAL
To access the engine or engine-related components, the vehicle power plant assembly must be removed as a whole unit by means of a slide-out cradle. The power plant assembly includes the engine, transmission (including retarder if so equipped), air compressor, alternator and transmission oil cooler.
Remove the power plant assembly as follows:
Caution: Tag hoses and cables for identification before disconnecting in order to facilitate reinstallation. Plug all openings to prevent dirt from entering the system.
Note: No parts within the ECM are serviceable.
If found defective, replace the complete ECM unit.
1. Disconnect the battery or batteries from the starting system by removing one or both of the battery cables from each battery system.
With the electrical circuit disrupted, accidental contact with the starter button will not produce an engine start. In addition, the Electronic Unit
Injectors (EUI) will be disabled, preventing any fuel delivery to the injector tips.
Warning: Due to the heavy load of the rear bumper assembly, it must be adequately supported before attempting to remove it.
2. Remove the rear bumper assembly from the vehicle. Refer to Section 18, BODY, under
"REAR BUMPER REMOVAL ".
3. Drain the engine cooling system. Refer to
Section 05, COOLING under "DRAINING
COOLING SYSTEM".
FIGURE 14: BELT TENSIONER VALVE
01063
4. Locate the belt tensioner pressure releasing valve (Fig. 14). Turn pressure releasing valve handle counterclockwise in order to release pressure in belt-tensioner air bellows and loosen belts. Remove the belts.
5. To release all pressure from the air system.
Refer to Section 12, BRAKES & AIR SYSTEM for instructions.
6. Disconnect and remove the engine-air intake duct mounted between air cleaner housing and turbocharger inlet (1, Fig. 16).
Caution: To avoid damage to turbocharger, cover the turbocharger inlet opening to prevent foreign material from entering.
7. Disconnect and remove the air intake duct mounted between the air cooler outlet and the engine intake (2, Fig. 16).
8. Disconnect and remove section of coolant pipe assembly mounted between the radiator outlet and the water pump inlet (3, Fig. 16).
9. Disconnect the coolant delivery hose located close to the water pump.
10. Disconnect the electric fan-clutch connector, close to the water pump (Fig. 15).
01-12
FIGURE 15: ELECTRIC FAN-CLUTCH CONNECTOR 010XX
Section 01: ENGINE
Disconnect the oil delivery hose from the valve located at the reserve tank drain
(7, Fig. 16).
21. Disconnect the power steering pump supply and discharge hoses. Cap hose openings immediately to limit fluid loss. Remove retaining clips from cradle (6, Fig. 16).
Close engine fuel supply shutoff valve on primary fuel filter. Disconnect the fuel line connected to inlet port. On vehicles equipped with the optional water-separator-fuel-filter, disconnect the connector and remove cable ties from cradle.
Disconnect the air compressor discharge, governor steel-braided airlines and manual filling airlines from compressor. Remove retaining clips. compressor head to the sump tank.
25. Disconnect ground cables from rear subframe ground-stud located close to the starter motor.
26. Disconnect positive cable (red terminal) from starting motor solenoid. bracket of the fan-drive assembly tensioner.
Remove the upper bracket (4, Fig. 16).
12. If necessary, remove the fan drive from the engine compartment by removing the four retaining bolts, washers and nuts securing the fan drive to the floor.
13. Disconnect and remove the air intake duct mounted between the turbocharger outlet and the air cooler inlet (5, Fig. 16). thermostat housing and from the coolant pipe assembly.
15. Disconnect and remove a section of coolant pipe assembly mounted between the thermostat housings and the radiator inlet.
Disconnect and remove the small hose connected to the heater line valve and to the water pump.
17. Disconnect the small heater hose located on the cylinder head at the back of the engine. main connectors from ECM and remove retaining clips from engine compartment backwall.
On vehicles equipped with an automatic transmission provided with a hydraulic output retarder, disconnect steel-braided airline from pressure regulator output. The pressure regulator is mounted in the upper section of engine compartment backwall and is accessible through the engine compartment
R.H. side door.
Disconnect fuel return line from bulkhead fixed on engine cylinder head end. mounted between the turbocharger outlet and the exhaust bellows. If necessary, refer to
Section EXHAUST SYSTEM under
MUFFLER REMOVAL AND INSTALLATION".
Caution:
To avoid damage to turbocharger, cover the turbocharger outlet opening to prevent foreign material from entering.
19. Disconnect the steel-braided airline from the
A/C compressor air bellows. operated cold-starting aid, disconnect the delivery hose from the starting-aid cylinder solenoid valve. Remove cable ties securing hoses.
31. Disconnect turbo boost pressure gauge airline from engine air intake.
32. Only if the vehicle is equipped with a retarder, remove the transmission rubber-damper assembly above transmission by removing: nut, bushing, rubber damper, rubber damper guide, bolt and washer. Remove the rubber damper bracket from transmission
01-13
Section 01: ENGINE
FIGURE 16: ENGINE COMPARTMENT
Disconnect connectors from transmission.
On the left side: four on rear side with one close to yoke. On right side: close to the solenoid valve of the output retarder. propeller shaft as detailed in Section 09, under heading "Propeller Shaft Removal".
35. Inspect the power plant assembly to ensure that nothing will interfere when sliding out the cradle. Check for connections or hoses not mentioned in this list as some vehicles are equipped with special or aftermarket components.
36. Remove the six retaining bolts, washers and nuts securing the power plant cradle to the vehicle rear subframe (Fig. 18).
Note : Check if any spacer(s) have been installed between power plant cradle and vehicle rear subframe, and if so, note position of each washer for reinstallation purposes.
37. Using a forklift, with a minimum capacity of
4,000 lbs (1 800 kg), slightly raise the power plant cradle. compartment. Make sure all lines, wiring and
01-14
01071 accessories are disconnected and are not tangled.
Caution : Due to the minimum clearance between the power plant equipment and the top of the engine compartment, extreme care should be used to raise the power plant cradle, just enough to free the cradle. Clearance between power plant cradle and mounting rail should range between ¼" and ½" (6-12 mm).
10. POWER PLANT ASSY. INSTALLATION
To install a power plant assembly, follow the same procedure as in "Power Plant Assembly
Removal" except in reverse order, then proceed with the following:
1. Torque the power plant cradle mounting bolts to 113-144 lbf•ft (153-195 N•m).
• For vehicles equipped with an Allison automatic transmission and a retarder:
Install transmission bracket (Fig. tighten to 71-81 lbf•ft (96-110 N•m). b) Install the transmission's rubber damper assembly above transmission by assembling: bolt, washer, rubber damper guide, rubber damper, bushing nut.
Section 01: ENGINE c)
(Fig. 17)
2. If fan drive has been removed, reinstall and align as per Section 05, COOLING
SYSTEM, under "FAN DRIVE
ALIGNMENT".
3. Refill cooling system with saved fluid (refer to Section 05, COOLANT SYSTEM).
4. Once engine fuel system has been drained, it will aid restarting if fuel filters are filled with fuel oil (refer to Section 03, FUEL SYSTEM).
FIGURE 17: RUBBER DAMPER TOLERANCE
07014
5. Start engine for a visual check. Check fuel, oil, cooling, pneumatic and hydraulic system connections for leakage. Test operation of engine controls and accessories.
11. VALVE COVER REMOVAL
Refer to the series 60 detroit diesel service manual for injectors and valves adjustment.
Access to engine cover differs depending on vehicle model.
Wait until engine is cold prior to working on vehicle.
11.1 XL2-45 COACHES AND MOTORHOMES
1. Remove air intake pipe.
2. Remove the after CAC (Charger-Air-Cooler) air pipe.
3. Disconnect ventilation pipe from valve cover.
4. Remove trap door located in the middle rear end of vehicle.
Note : On coaches, last seat has to be removed to access trap door. On motorhomes, it will depend on interior design.
5. Remove engine cover.
6. Adjust Jake brakes (if applicable), injectors and valves using Detroit Diesel service manual for series 60 engines.
7. Verify engine cover gasket and replace if necessary.
Note : New gasket must be ordered directly from Detroit Diesel.
8. Reinstal engine cover with a tightening torque of 18-22 Lbf·ft (25-30 N·m).
9. Connect ventilation pipe to engine cover.
10. Reinstall air intake and after CAC air pipes.
11. Reinstall trap door, seats or interior finish for motorhomes.
11.2 XL2-40 COACHES
1. Close both heat system supply and return valves (see chapter 4.7 of section 5 in XL2 maintenance manual).
2. Drain coolant and remove exit thermostathousing pipe.
3. Remove air intake pipe.
4. Remove the after CAC (Charger-Air-Cooler) air pipe.
5. Disconnect ventilation pipe from valves cover.
6. Remove engine cover.
7. Adjust Jake brakes (if applicable), injectors and valves using Detroit Diesel service manual for series 60 engines.
8. Verify engine cover gasket and replace if necessary.
Note : New gasket must be ordered directly from
Detroit Diesel.
9. Reinstall engine cover and tighten bolts to
18-22 Lbf·ft (25-30 N·m).
10. Reconnect ventilation pipe to engine cover.
11. Reinstall exit thermostat-housing, air intake and after CAC air pipes.
12. Fill up coolant (Refer to section 5 in maintenance manual) .
01-15
Section 01: ENGINE
13. Open both heat system supply and return valves.
12. JAKE BRAKE
Refer to both "The Jake Brake Troubleshooting and Maintenance Manual" and "Installation
Manual for Model 790 Engine Brakes" for troubleshooting and installation procedures.
They are annexed at the end of this section.
13. ENGINE MOUNTS
The power plant assembly is mounted to the cradle by means of four rubber mounts.
Two rubber mounts are used at the front of the engine while two others are mounted on each side of the flywheel housing on vehicles equipped with an automatic transmission
(Fig. 18).
It is recommended that new rubber mounts be installed at each major overhaul.
FIGURE 18: POWER PLANT CRADLE INSTALLATION
01032
01-16
14. ENGINE TROUBLESHOOTING GUIDE
START
Section 01: ENGINE go to step 2 no does the engine rotate ?
yes go to step 3 yes does the red
"Stop Engine" indicator illuminate and go off after 5 sec. ?
no faulty 12-volt-system power supply, probable causes :
- battery cables improperly connected
- fuse blown
- faulty battery equalizer
- activate the DDEC self-diagnostic system and contact your Detroit Diesel service center step 2 no is the engine starting ?
yes see note 1 plug the Diagnostics Data
Reader DDR into the receptacle or momentarily depress the stop engine "OVERRIDE" switch to activate the DDEC self-diagnostic system with diagnostic code in hand, contact your
Detroit Diesel service center engine does not rotate there may be a problem with the starter or starter circuit. Contact Detroit
Diesel or Prévost Action
Service yes what is the voltage reading on 24-voltsystem dashboard indicator ?
lower than
24 volts faulty 24-volt-system power supply or low battery voltage. Contact
Prévost Action Services higher than
24 volts is the shift selector to neutral "N" position ?
no place the shift selector to neutral "N" position and start the engine yes is the rear start selector to
"NORMAL" position?
no
Set the rear start selector to "NORMAL"
01-17
Section 01: ENGINE step 3 note 1
REFERENCES
-Operator's Manual chap. 3,4 & 8
-Detroit Diesel pamphlet "DDEC
III/IV diagnostic codes and MPSI reader functions"
-8V92 series engine, switch is located in service compartment with diagnostic code in hand, contact your
Detroit Diesel service center note 2 see the analog voltage indicator on the dashboard or consult the
MCD "Message Center Display" on the telltale panel. See the
Operator's Manual chap. 4 for more details is there motor exhaust fumes
?
yes voir note 1 plug the Diagnostics Data
Reader DDR into the receptacle or momentarily depress the stop engine
"OVERRIDE" switch to activate the DDEC selfdiagnostic system no probable causes :
- 12-volt-system batteries low
- faulty battery equalizer
- 12-volt-system batteries improperly connected
- 12-volt-system battery master switch to "OFF" position (H3-40) lower than
10 volts what is the voltage reading on the
12-volt-system indicator ?
higher than
10 volts see note 2 probable cause :
-no fuel
-check the 2 breakers on the injector feeding system.
Contact Detroit Diesel or Prévost Action Service
01089
15. SPECIFICATIONS
Series 60 Engine
Make .........................................................................................................................................Detroit Diesel
Type............................................................................................................... Diesel four cycle/in-line engine
Description.......................................................................................................Turbo/Air to air charge cooled
No. of cylinders ............................................................................................................................................. 6
Operating range.................................................................................................................... 1200-2100 RPM
Maximum RPM ........................................................................................................................................2100
Displacement, 12.7 Liters:
Bore & Stroke ............................................................................................. 5.12 X 6.30 in (130 X 160 mm)
Displacement, 12.7 Liters:
Bore & Stroke ............................................................................................. 5.12 X 6.30 in (130 X 160 mm)
Horsepower Range ....................................................................................................................... 500 BHP
Lubricant
Heavy-duty engine oil SAE Viscosity Grade 15W-40, API Classification CH-4 and meeting MIL-L-2104 D or E specifications. Synthetic oil may be used if it meets the performance and chemical requirements of non-synthetic oils outlined previously. Some engine operating conditions may require exceptions to this recommendation.
01-18
Section 01: ENGINE
Caution : To avoid possible engine damage, do not use single grade (Monograde) lubricants in Detroit
Diesel four-cycle Series 60 engines, regardless of API classification.
Capacity
Oil reserve tank..................................................................................................................8.4 US qts (8.0 L)
Engine oil level quantity (Series 60)
Oil Pan Capacity, Low Limit.............................................................................................. 26 quarts/25 liters
Oil Pan Capacity, High Limit............................................................................................. 32 quarts/30 liters
Total Engine Oil Capacity with Filters............................................................................... 41 quarts/39 liters
Lubricating oil filter elements
Make .................................................................................................. AC Rochester Div. GMC # 25014505
Make ............................................................................................................................. A/C Filter # PF-2100
Type................................................................................................................................................ Full Flow
Prévost number .................................................................................................................................510458
Torque specification
Engine oil filter ..............................................................................Tighten 2/3 of a turn after gasket contact
Filters
Engine Air Cleaner Filter
Make..............................................................................................................................Nelson # 70337-N
Prévost number .............................................................................................................................530197
Engine Coolant Filter/Conditioner
Make............................................................................................. Nalco Chemical Company # DDF3000
Make................................................................................................................. Detroit Diesel # 23507545
Prévost number ..............................................................................................................................550630
Note: For primary and secondary fuel filters, refer to Specifications in section 03.
01-19
SERIES 60 SERVICE MANUAL
4. Install the bolts that secure the accessory drive housing to the gear case cover and tighten to 30–38 N·m (22–28 lb·ft) torque using the pattern shown. See Figure 1–413.
Figure 1-413 Accessory Drive Housing Bolt Torque Sequence
5. Check the bull gear-to-accessory drive gear backlash. Refer to section 1.21.2.1.
6. Adjust the alternator belts. Refer to section 13.12.10.
7. Tighten the alternator mounting bolts.
8. Install any other components removed for this procedure.
9. Refer to section 11.3 for verification of proper accessory drive installation.
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-521
1.29
JAKE BRAKE
1.29 JAKE BRAKE
The engine brake has been designed to fit on the Series 60 engine with no additional valve cover spacers. There are three styles of valve covers for the Series 60 engine. On engines equipped with a two-piece aluminum valve cover, it is NOT necessary to remove the lower valve cover to install the engine brake. However, one style of upper valve cover may require modification at the breather housing location (inside) for engine brake clearance.
The model, part number and serial number are located on the nameplates at the top of each housing. See Figure 1-414.
1. Identification Plate
Figure 1-414 Nameplate Location on Housing
NOTICE:
Only the specific brake model can be used with the engine model it was designed for. Also, the correct slave piston adjustment specification must be used. Failure to follow these instructions may result in serious engine or engine brake damage.
Listed in Table 1-9 are the different Jake Brake models used and the slave piston adjustment specification.
1-522 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
Model Number
6067WU40
6067GU40
6067WU60
6067GU40
6067GU28
6067GU91
6067WK60
6067GK60
6067GK28
6067EK60
6067PK60
6067TK60
6067TK45
6067MK60
6067BK60
6067HKXX
Model Year
Pre-1991
Pre-1991
1991
1991
1991
1991
1994
1994
1994
1998
1998
1998
1998
1998
1998
1998 (Non-Line
Haul)
Engine
Displacement
11.1L
12.7L
11.1L
12.7L
12.7L
12.7L
11.1L
12.7L
12.7L
11.1L
12.7L
12.7L
12.7L
12.7L
12.7L
14L
Engine Brake
760/760A
760/760A
760/760A
765
765
765
760A
765
765
760B
765A
765A
765A
770
770
770 0.660 mm (0.023 in.)
6067MK28,
6067MK45,
6067MK57,
6067MK60
6067BK28,
6067BK45,
6067BK57, 6067BK60
6067HK45, 6067HK60
6067WK28,
6067WK60
6067LK28, 6067LK45,
6067LK60
6063GK60,
6067GK28,
6067GK45,
6067GK91,
6067PK62, 6067TK28,
6067TK60, 6067TK62
6067HK62
2000
2000
2000
2000
2000
2000
2000
12.7L Standard
12.7L Premium
14L U.S.
11.1L
11.1L
12.7L
14L Australian
790
790
790A
790B
790B
790B
790C
0.660 mm (0.026 in.)
0.660 mm (0.026 in.)
0.660 mm (0.026 in.)
0.660 mm (0.026 in.)
0.660 mm (0.026 in.)
0.660 mm (0.026 in.)
0.660 mm (0.026 in.)
All slave piston adjustments shown here are current as of the date of this manual and supersede all previous adjustments.
XXXX = Model numbers to be determined.
Table 1-9 Jake Brake Model Information
Slave Piston
Adjustment
0.660 mm (0.026 in.)
0.508 mm (0.020 in.)
0.660 mm (0.026 in.)
0.660 mm (0.026 in.)
0.660 mm (0.026 in.)
0.660 mm (0.026 in.)
0.660 mm (0.026 in.)
0.660 mm (0.026 in.)
0.660 mm (0.026 in.)
0.584 mm (0.023 in.)
0.584 mm (0.023 in.)
0.584 mm (0.023 in.)
0.584 mm (0.023 in.)
0.660 mm (0.023 in.)
0.660 mm (0.023 in.)
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-523
1.29
JAKE BRAKE
NOTE:
All engines built after serial number 06R0004455 have the correct engine parts for engine brake installation. The model numbers have changed because of design changes in the engine brakes.
NOTE:
All Series 60 engines with serial numbers 06R0004455 or higher are Jake Brake ready.
Do not install a Jake Brake on engines with lower serial numbers.
Effective December 16,1999, Model 790 Jake Brakes are used on all Series 60 engines requiring an engine brake.
Former Jake Brake production models for the Series 60 engine were the 760A (which replaced model 760), 760B, 765, 765A, and 770.
Detroit Diesel engine model Nos. 6067GU28 and 6067GK28 are for bus/coach applications. Due to interference fits on some coach chassis, a two-housing Jake Brake kit may be required. Contact your Detroit Diesel Distributor for information on these kits.
1-524 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
Energizing the engine brake effectively converts a power-producing diesel engine into a power-absorbing air compressor. This is accomplished through motion transfer using a master-slave piston arrangement which opens cylinder exhaust valves near the top of the normal compression stroke, releasing the compressed cylinder charge to exhaust. See Figure 1-415.
1. Exhaust Valve
2. Slave Piston Assembly
3. Exhaust Valve
4. Leveling Screw
5. Slave Piston Adjusting Screw
6. Accumulator
Figure 1-415 Jake Brake Schematic
7. Oil In
8. Check Valve (Model 760)
9. Solenoid Valve
10. Control Valve
11. Master Piston
12. Injector Pin and Roller
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-525
1.29
JAKE BRAKE
The blowdown of compressed air to atmospheric pressure prevents the return of energy to the engine piston on the expansion stroke, the effect being a net energy loss, since the work done in compressing the cylinder charge is not returned during the expansion process.
Exhaust blowdown occurs as the energized solenoid valve permits engine lube oil to flow under pressure through the control valve to both the master piston and the slave piston. See Figure 1-415.
Oil pressure causes the master piston to move down, coming to rest on the injector rocker arm roller.
The injector rocker arm begins its travel as in the normal injection cycle, moving the master piston upward and directing high-pressure oil to the slave piston. The ball check valve in the control valve traps high-pressure oil in the master-slave piston system.
High pressure oil causes the slave piston to move down, momentarily opening the exhaust valves, while the engine piston is near its top-dead-center position, releasing compressed cylinder air to the exhaust manifold.
At the bottom of its stroke, the slave piston separates from the valve in the slave piston adjusting screw, allowing high pressure oil to flow into the accumulator. This reduces the pressure in the high pressure circuit, permitting the slave piston to retract and the exhaust valves to close in preparation for the normal exhaust valve cycle. The oil pressure reserved in the accumulator ensures that the hydraulic circuit is fully charged for the next cycle. Compressed air escapes to the atmosphere, completing a compression braking cycle.
1-526 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
The Jake Brake is electronically controlled. Jake Brake control system wiring will vary depending on the vehicle manufacturer. For a general overview of the Jake Brake, see Figure 1-416 and see Figure 1-416a.
1. Ball Check Valve (Model 760 Only)
2. Control Valve
3. Solenoid Valve
4. Accumulator Piston
Figure 1-416
5. Power Lash Assembly
6. Slave Piston
7. Bridge
8. Master Piston
Typical Model 760, 765, or 770 Jake Brake Assembly
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-527
1.29
JAKE BRAKE
1. Solenoid Valve
2. Upper Seal
3. Center Seal
4. Lower Seal
5. Master Piston
6. Master Piston Pushrod
7. Master Piston Spring
8. Washer
9. Retaining Ring
10. Control Valve
11. Outer Control Valve Spring
12. Inner Control Valve Spring
13. Washer
14. Retaining Ring
15.J-Lash ® Screw
16. Locknut
17. Slave Piston
18. Slave Piston Bridge
19. Outer Slave Piston Spring
20. Inner Slave Piston Spring
21. Slave Piston Spring Seat
22. Shoulder Bolt
Figure 1-416a Typical Model 790 Jake Brake Assembly
NOTICE:
This application and adjustment information must be strictly followed. Failure to follow these instructions may result in serious engine or engine brake damage.
1-528 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
1.29.1
Repair or Replacement of Jake Brake
To determine if repair is possible or replacement is necessary, perform the following procedure.
See Figure 1-417.
Figure 1-417 Jake Brake Repair or Replacement Flowchart
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-529
1.29
JAKE BRAKE
1.29.2
Removal of Model 760, 765, or 770 Jake Brake
Remove the model 760, 765, or 770 Jake Brake as follows:
NOTE:
The following procedures apply to Model 760, 765, and 777 Jake Brakes. For Model 790
Jake Brake removal procedures, refer to section 1.29.6.
To avoid possible personal injury, never remove any engine brake component with engine running.
1. Disconnect starting power for engine. Refer to OEM guidelines.
2. Remove the engine rocker cover. Refer to section 1.6.2 for one-piece, refer to section 1.6.3
for two-piece and refer to section 1.6.5 for three-piece.
NOTE:
If the engine is equipped with an aluminum two-piece valve cover, remove only the upper valve cover when installing the engine brake.
3. Note the location of the rocker arm shaft, the exhaust valve rocker arm, the fuel injector rocker arm, and the intake valve rocker arm.
4. Disconnect the solenoid wiring harness connectors from the engine brake solenoids.
See Figure 1-418.
1-530 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
1. Cylinder Head
2. Jake Brake Assembly
3. Solenoid
Figure 1-418 Jake Brake Assembly
4. Washers (3 each)
5. Mounting Bolts (3 each)
6. Engine Brake Harness
5. Remove the nine mounting bolts and washers that secure the engine brake assemblies to the cylinder head. See Figure 1-418.
NOTE:
Only the Model 760 Jake Brake uses two different length mounting bolts. Six bolts, 120 mm (4.72 in.) long, are used on the exhaust side of the engine. Three bolts, 110 mm
(4.33 in.) long, are used on the intake side of the engine. These bolts must be reinstalled in their correct positions.
6. Remove the engine brake assemblies and the spacer bar.
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-531
1.29
JAKE BRAKE
1.29.3
Disassembly of Model 760, 765, or 770 Jake Brake
Remove the control valve as follows:
To avoid personal injury, remove control valve covers carefully. Control valve covers are under load from the control valve springs.
1. Press down on control valve washer using an appropriate diameter rod to relieve spring pressure. See Figure 1-419.
1. Jake Brake Assembly
2. Spring
Figure 1-419
3. Snap Ring Retainer
4. Snap Ring Pliers
Relieving Spring Pressure
1-532 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
2. Using retaining ring pliers, remove retaining ring.
3. Slowly remove cover until spring pressure ceases, then remove the two control valve springs and collar. See Figure 1-420.
1. Jake Brake Assembly
2. Control Valve
3. Collar
4. Snap Ring Retainer
Figure 1-420
5. Washer
6. Collar Spring
7. Control Valve Spring
Removing Control Valve Springs and Collar
4. Using needle-nose pliers, reach into the bore and grasp the stem of the control valve.
Remove control valve.
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-533
1.29
JAKE BRAKE
Remove the slave piston adjusting screw as follows:
1. Loosen slave piston adjusting screw locknut.
2. Remove adjusting screw from housing. See Figure 1-421.
1. Jake Brake Assembly
Figure 1-421
2. Slave Piston Adjusting Screw
Removing Slave Piston Adjusting Screw
1-534 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
Remove the solenoid valve as follows:
NOTICE:
To avoid possible engine damage, do not disassemble or tamper with the solenoid valve.
1. Disconnect solenoid valve harness.
2. Using a 7/8 in. socket and extension for former solenoids or a 3/4 in., 6 point socket and extension for current solenoids, unscrew solenoid valve.
3. Remove and discard the three rubber seal rings. See Figure 1-422.
1. Seal Rings (3)
Figure 1-422
2. Solenoid
Removing Rubber Seal Rings
4. If the lower ring stays in the bottom of the housing bore, remove with a piece of wire.
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-535
1.29
JAKE BRAKE
Remove the accumulator as follows:
The accumulator spring is under strong compression. To avoid possible personal injury if the accumulator spring is discharged, wear safety glasses and use caution when removing the retaining ring and cover.
1. Push down on the accumulator cover using the appropriate diameter rod, and remove the retaining ring. See Figure 1-423.
1. Jake Brake Assembly
2. Retaining Ring
Figure 1-423
3. Retaining Ring Pliers
Removing Retaining Ring
2. Relieve pressure on the accumulator cover.
3. Remove the cover and spring.
1-536 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
4. Use a magnet to remove the piston from the accumulator bore. See Figure 1-424.
1. Jake Brake Assembly
2. Piston
3. Spring
Figure 1-424
4. Retaining Ring
5. Washer
Removing Piston from Accumulator Bore with Magnet
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-537
1.29
JAKE BRAKE
Remove the master piston as follows:
1. Remove the screw, washer, and master piston spring from the housing.
2. Remove the master piston. See Figure 1-425.
NOTE:
Use needle-nose pliers, if necessary.
1. Washer and Screw Assembly
2. Jake Brake Assembly
Figure 1-425
3. Master Piston
4. Master Piston Spring
Removing The Master Piston
On Model 760 only, remove the ball check valve as follows:
1. Remove the plug.
2. Remove the ball check valve and spring.
1-538 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
Remove the slave piston as follows:
1. Remove the screw and spring that retains the slave piston return spring.
2. Remove the bridge and the slave piston. See Figure 1-426.
1. Slave Piston Bridge
2. Jake Brake Housing
3. Slave Piston
Figure 1-426
4. Return Spring
5. Washer
6. Screw
Removing Bridge and Slave Piston
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-539
1.29
JAKE BRAKE
3. Loosen the leveling screw locknut and remove the leveling screw from the bridge.
See Figure 1-427.
1. Slave Piston Bridge
Figure 1-427
2. Slave Piston Leveling Screw
Removing the Leveling Screw from the Bridge
The injector rocker arm contains a pin and roller for actuating the engine brake master piston. If excessive wear or damage to the roller is present, replace the rocker arm assembly.
Refer to Section 1.6.2.
1-540 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
1.29.3.1
Cleaning of Model 760, 765, or 770 Jake Brake
Clean the Jake Brake as follows:
NOTE:
Use an OSHA-approved cleaning solvent when washing parts. Be sure to coat parts with clean engine oil when reinstalling them.
1. Wash the control valves with approved cleaning solvent.
2. Push a wire through the hole in the base of the valve to the distance required to ensure that the ball check is free.
NOTE:
The ball should lift with light pressure on the wire.
To prevent possible personal injury when using compressed air, wear adequate eye protection (face plate or safety glasses) and do not exceed 40 psi (276 kPa) air pressure.
3. Dry the valve with compressed air, and wipe clean with a paper towel.
4. Thoroughly clean the control valve bore in the housing using clean paper towels.
5. Clean slave piston adjusting screw in an approved cleaning solvent.
6. Clean out the solenoid valve bore in the housing.
NOTICE:
Use clean paper towels to clean the solenoid valve bore. Never use rags, as they may leave lint and residue which can plug the oil passageways, causing Jake Brake malfunction.
7. Clean the master piston in approved cleaning solvent.
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-541
1.29
JAKE BRAKE
1.29.3.2
Inspection of Model 760, 765, or 770 Jake Brake
The Jacobs engine brake is typically a trouble-free device. However, inspections are necessary and some maintenance is required. Use the following procedures to keep the engine brake in top condition.
Inspect the Jake Brake as follows:
1. Inspect slave piston adjusting screw for protrusion, spring pressure and freedom of movement.
NOTE:
The plunger should protrude from the bottom of the screw, have light spring pressure apparent when depressed, and move freely. Be sure the retaining ring is fully engaged in its groove (groove is located on the bottom of the reset screw and top of the
POWER-LASH assembly).
[a] If the plunger does not protrude, the spring does not have light pressure or does not move freely, replace the entire screw assembly. Refer to Section 1.29.4
[b] If the slave piston adjusting screw meets specifications, continue with inspection.
2. Inspect the accumulator for wear or damage.
[a] If worn or damaged, replace the accumulator. Refer to Section 1.29.4.
[b] If accumulator is not worn or damaged, continue with inspection.
3. Inspect the master piston bore for wear or damage.
NOTE:
Some wear marks are permissible.
[a] If worn or damaged, replace the master piston. Refer to Section 1.29.4.
[b] If not worn or damaged, continue with inspection.
4. Apply clean lube oil to the piston, and insert into bore.
NOTE:
Master piston should move in and out freely with no binding.
[a] If binding occurs, replace master piston and/or housing. Refer to Section 1.29.4.
[b] If no binding occurs, continue with inspection.
5. Inspect master piston spring for relaxation.
NOTE:
The spring should hold the master piston completely in the housing.
[a] If relaxed, replace the spring. Refer to Section 1.29.4.
[b] If spring holds tightly, continue with inspection.
1-542 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
6. Inspect the ball check valve (Model 760 only) for wear or damage.
[a] If worn or damaged, replace ball check valve. Refer to Section 1.29.4.
[b] If not worn or damaged, proceed with inspection.
7. Inspect slave piston components for excessive wear or damage.
[a] If worn or damaged, replace slave piston component.
[b] If not worn or damaged, proceed with inspection.
1.29.3.3
Inspection of Control Valve
Inspect the control valve as follows:
1. Dip the control valves in clean lube oil.
2. Holding the control valve by the stem, let it drop into the bore.
[a] If binding occurs or if the ball sticks in the valve, replace the control valve.
Refer to Section 1.29.4.
[b] If no binding occurs and the ball does not stick in the control valve, assemble the
Jake Brake. Refer to Section 1.29.4.
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-543
1.29
JAKE BRAKE
1.29.4
Assembly of Model 760, 765, or 770 Jake Brake
Install the control valve as follows:
1. Slip the control valve into the bore. See Figure 1-428.
NOTE:
Make sure the control valve collar is installed with the longer sleeve area facing up. If the collar is installed upside down, the engine brake cylinder will not operate.
1. Jake Brake Assembly
2. Control Valve
3. Collar
4. Snap Ring Retainer
Figure 1-428
5. Washer
6. Collar Spring
7. Control Valve Spring
Installing the Control Valve
2. Install the control valve collar and two springs.
NOTE:
Ensure the collar is installed with the longer sleeve area facing up. If the collar is installed upside down, the engine brake cylinder will not operate.
3. Press the cover (washer) into place.
4. While holding the cover tightly in place, install the retaining ring.
5. Rotate retaining ring ears 90 degrees to assure ring is seated in groove.
1-544 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
Install the slave piston adjusting screw as follows:
1. Place the screw in the housing. See Figure 1-429.
SERIES 60 SERVICE MANUAL
1. Jake Brake Assembly
Figure 1-429
2. Slave Piston Adjusting Screw
Installing the Slave Piston Adjusting Screw
2. Torque the slave piston adjusting screw locknut to 35 N·m (25 lb·ft).
Install the solenoid valve as follows:
NOTE:
As of October 19, 1997, former solenoids have been replaced with the current improved solenoids. The current solenoids have an increased installation torque and improved durability. The current solenoid is interchangeable with the former.
1. Coat new solenoid valve seal rings with clean lube oil.
NOTE:
Use current upper seals when installing current solenoids. New seals are identified with yellow stripes.
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-545
1.29
JAKE BRAKE
2. Install the upper and center seal rings on the solenoid valve body and the lower seal ring into the bottom of the bore in the housing. See Figure 1-430.
1. Seal Rings (3)
Figure 1-430
2. Solenoid
Installation of Solenoid Valve Seal Rings
3. Make sure the seals are seated properly.
4. Using a 7/8 in. socket and extension for former solenoids or a 3/4 in., 6 point socket and extension for current solenoids, carefully screw the solenoid valve into the housing without unseating the seals.
5. Torque the former solenoid to 12.4 N·m (9 lb·ft). Torque the current solenoid to 20 N·m
(15 lb·ft.)
NOTE:
Be careful not to twist the seals while installing.
Install the accumulator as follows:
1. Place the piston into the accumulator bore.
2. Insert the spring, and install the cover.
3. Push down the accumulator cover, and insert retaining ring.
1-546 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
Install the master piston as follows:
1. Apply clean lube oil to the piston.
2. Insert master piston into bore. See Figure 1-431.
SERIES 60 SERVICE MANUAL
1. Washer and Screw Assembly
2. Jake Brake Assembly
Figure 1-431
3. Master Piston
4. Master Piston Spring
Inserting Master Piston into Bore
3. Install spring, washer, and screw.
NOTE:
Make sure spring legs are centered around master piston boss.
4. Torque screw to 10 N·m (7.4 lb·ft).
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-547
1.29
JAKE BRAKE
On model 760 only, install the ball check valve as follows:
1. Install the ball check valve and spring. See Figure 1-432.
1. Ball Check Valve
2. Spring
Figure 1-432
3. Pipe Plug
Installation of Ball Check Valve
2. Insert the plug. Torque pipe plug to 11.2 N·m (8.3 lb·ft).
1-548 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
Install the slave piston as follows:
1. Install the screw from the slave piston side of the bridge.
2. Install the leveling screw locknut.
3. Install the bridge with the leveling screw toward the center of the housing.
See Figure 1-433.
1. Washer
2. Screw
3. Torsion Spring
Figure 1-433
4. Bridge Assembly
5. Jake Brake Housing
Installing Bridge with Leveling Screw Toward Center of Housing
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-549
1.29
JAKE BRAKE
4. Install the slave piston assembly torsion spring with the ends over the bridge.
See Figure 1-434.
Figure 1-434 Installing the Slave Piston Assembly Torsion Spring
5. Install the screw over the center part of the spring.
NOTICE:
While tightening the screw on the torsion spring, push the spring toward the slave piston assembly. Failure to do so may result in contact between the intake valve adjusting screw and torsion spring. Serious engine damage may result.
6. Torque the screw to 20 N·m (15 lb·ft.).
7. Torque the slave piston leveling screw locknut to 47 N·m (35 lb·ft.).
1-550 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
1.29.5
Installation of Model 760, 765, or 770 Jake Brake
Install the model 760, 765, or 770 Jake Brake as follows:
NOTE:
The following procedures apply to Model 760, 765, and 770 Jake Brakes. For Model 790
Jake Brake installation procedures, refer to section 1.29.10.
1. Adjust the intake and exhaust valve clearances and set the injector heights.
Refer to section .
To prevent possible personal injury when using compressed air, wear adequate eye protection (face plate or safety glasses) and do not exceed 40 psi (276 kPa) air pressure.
2. Attach the length of tubing to a blow gun nozzle, and blow out the oil from the bolt holes.
3. Cover the holes with hand towels to minimize oil spray.
NOTE:
Removing the oil from the bolt holes prevents the cylinder head from cracking when tightening the bolts.
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-551
1.29
JAKE BRAKE
4. Place the spacer bar on the exhaust manifold side of the cylinder head with the "OUT" markings adjoining each other and facing the exhaust manifold. See Figure 1-435, and see Figure 1-436.
Figure 1-435 Spacer Bars with "Out" Marks Adjoined
1-552 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
Figure 1-436 Location of Spacer Bars
5. Place the three engine brake housings over the rocker shafts with the solenoid valves toward the camshaft side of the engine.
NOTE:
Be sure housings do not interfere with wiring harness.
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-553
1.29
JAKE BRAKE
NOTICE:
Do not mix the rocker arm shaft bolts and the Jake Brake mounting bolts. If the rocker arm shaft bolt is mistakenly used to mount the
Jake Brake housing, the longer shoulder on the bolt will block the oil supply to the Jake Brake on the camshaft side of the housing.
The brake will not retard the engine as designed. This condition could cause loss of vehicle braking control on downgrades, which may create a risk of personal injury to the vehicle operator or other persons and damage to the vehicle or property of others.
NOTE:
The rocker arm shaft mounting bolt and Jake Brake mounting bolt, part of the Jake
Brake assembly, are similar in appearance. Both are M12 x 110 mm (4.33 in.) long and have 12–point heads.
NOTE:
In the event of a housing hold down bolt failure on a Jacobs engine brake housing, replace all bolts on that particular housing.
NOTICE:
Use bolts that have the Jacobs logo, circled "J". Installation of bolts that do not have the circled "J" may result in damage to the engine, engine brake or both.
[a] The Jake Brake bolt has the Jacobs logo (circled "J") and the letters "EF" marked on the head. The bolt length is no longer marked atop the bolt head.
[b] The DDC rocker arm shaft bolt has the DDC logo (spinning arrows) and the vendor
I.D. (F-C) on its head.
[c] Jake Brake model 760 requires two bolts along with one bolt and new washers.
NOTE:
Be sure that only Jake Brake bolts, see Figure 1-437, are installed in the Jake Brake housing.
1-554 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
[d] The DDC bolt shoulder is much longer, 17.0 mm (0.669 in.) versus 4 mm (0.157 in.) than the Jake Brake bolt. See Figure 1-437.
Figure 1-437 Jake Brake and DDC Bolt Identification
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-555
1.29
JAKE BRAKE
NOTICE:
The model 760 uses two lengths of mounting bolts. Six 120 mm bolts should be installed on the exhaust side of the engine. Three
110 mm bolts should be installed on the camshaft side of the engine. Failure to do so will result in engine damage.
6. On model 760, install one washer onto each 120 mm (4.75 in.) bolt, and insert into brake housing on the exhaust manifold side (two per housing). See Figure 1-438.
1. Washer
Figure 1-438
2. Long Bolt
Installation of Brake Housing Bolts on Exhaust Manifold Side
1-556 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
7. On model 760, install one washer on the 110 mm (4.375 in.) bolt, and insert into brake housing at the camshaft side (one per housing). See Figure 1-439.
1. Jake Brake Housing Assembly
Figure 1-439
2. Mounting Bolt
Installation of Brake Housing Bolts on Camshaft Side
8. On models 760A, 760B, 765, and 765A, lubricate each hold down bolt with clean engine oil.
NOTE:
All the housing mounting bolts for these models are the same length of 110 mm
(4.375 in.).
9. On models 760A, 760B, 765, and 765A, install a washer on each bolt, and install into housings (three bolts per housing).
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-557
1.29
JAKE BRAKE
10. On models 760A and 765, move the housing from side to side, and locate the housing in the center position of the movement. See Figure 1-440.
Figure 1-440 Locating Center Position of Housing
11. On models 760B and 765A, move the housing from side to side, and locate as far toward the camshaft side of the engine as possible.
12. On all models, torque the engine brake mounting bolts using the following sequence:
[a] Torque the three bolts on the camshaft side of the engine to 55 N·m (40 lb·ft).
[b] Torque the six bolts on the exhaust manifold side of the engine to 55 N·m (40 lb·ft).
[c] Repeat the tightening sequence and re-torque all bolts to 136 N·m (100 lb·ft).
[d] Check the torque to 136 N·m (100 lb·ft).
13. Secure wire harness to spacer bars with plastic ties.
14. Connect wiring harness solenoid connectors to solenoids.
1-558 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
1.29.5.1
Adjustment of Slave Piston on Model 760, 765, or 770 Jake Brake
Make the following adjustment with the engine stopped and cold, and the oil temperature at 60 C
(140 F) or below. The exhaust valves on the cylinder must be in the closed position (rocker arm roller on the base circle of the camshaft). When setting the engine brake lash, the exhaust valves must be in the closed position. Adjust the slave piston on all models as follows:
NOTE:
The following procdures apply to Model 760, 765, and 770 Jake Brakes. For Model 790
Jake Brake slave piston lash setting procedures, refer to section 1.29.10.1.
NOTE:
Model 770 Jacobs engine brake requires a special procedure for adjusting the slave piston. The procedure is clearly indicated in the following adjustment steps.
NOTICE:
Improper slave piston adjustment can result in engine or brake housing damage.
NOTICE:
Strictly follow the slave piston adjustment procedure. Failure to use the proper adjustment procedure will result in poor engine brake performance and/or serious engine damage.
1. Refer to section 1.29 for proper slave piston clearance setting.
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-559
1.29
JAKE BRAKE
2. Back out the leveling screw in the slave piston assembly until the end of the screw is beneath the surface of the bridge in the slave piston assembly. See Figure 1-441.
NOTE:
The leveling screw is located in the bridge member of the slave piston assembly.
1. Leveling Screw
Figure 1-441
2. Locknut
Location of Leveling Screw
3. On models 760, 760A, 760B, 765, and 765A, place the correct size feeler gage between the solid side of the slave piston (the side without the leveling screw) and the exhaust rocker arm adjusting screw. Feeler gage sizes are listed in Table 1-9.
1-560 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
4. On models 760, 760A, 760B, 765, and 765A, turn the slave piston adjusting screw clockwise until a slight drag is felt on the feeler gage. See Figure 1-442.
1. Slave Piston Bridge
2. Slave Piston Adjusting Screw
Figure 1-442
3. Feeler Gage
Turn Slave Piston Adjusting Screw Clockwise
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-561
1.29
JAKE BRAKE
5. Perform the following additional steps on model 770:
[a] Turn in the J-Lash
®
adjusting screw until the solid side of the slave piston bridge assembly contacts the exhaust valve and the valve springs begin to compress. Turn in one additional turn.
NOTICE:
All oil must be purged from the J-Lash adjusting screw. Oil remaining in the J-Lash screw will cause inaccurate clearance adjustment, resulting in possible engine or engine brake damage.
If oil is below room temperature (below 60 F), wait at least two minutes for oil to be purged from the J-Lash adjusting screw.
NOTE:
Wait at least 30 seconds for oil to be purged from the J-Lash adjusting screw.
[b] Back out the adjusting screw only until the correct size feeler gage can be inserted between the solid side of the slave piston bridge assembly and the exhaust valve.
[c] Adjust the J-Lash so that a light drag is felt on the feeler gage.
NOTE:
Do not back out the J-Lash more than required to obtain a light drag on the feeler gage.
[d] Use a screwdriver to hold the J-Lash in place, and torque the lock nut to 34 N·m
(25 lb·ft).
NOTE:
If the J-Lash screw is backed out until it no longer compresses the slave piston spring, oil will enter the screw and the adjustment will be incorrect. If this occurs, repeat the
J-Lash adjustment procedure.
[e] Recheck the lash settings. If clearance setting is incorrect, repeat the J-Lash adjustment procedure.
NOTE:
Once the engine brake has been run, oil enters the J-Lash screw making the engine brake adjustment unreadable. If unsure of the adjustment, repeat the J-Lash adjustment procedure.
6. On all models, hold the screw in position, and torque the locknut to 35 N·m (26 lb·ft).
7. Check the adjustment, and repeat if necessary.
NOTE:
Do not disassemble the slave piston adjusting screws.
8. Place the correct feeler gage between the leveling screw and the rocker arm adjusting screw.
1-562 From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
9. Turn the leveling screw clockwise until a slight drag is felt on the feeler gage.
See Figure 1-443.
1. Feeler Gage
2. Slave Piston Leveling Screw
Figure 1-443
3. Rocker Arm Adjusting Screw
Setting Clearance on Leveling Screw and Rocker Arm Adjusting
Screw
10. Hold the leveling screw in position, and torque the locknut to 47 N·m (35 lb·ft).
11. Check adjustment, and repeat if necessary.
12. Repeat the adjustment procedures for the remaining cylinders. Refer to step 2 through step 11.
NOTE:
Bar over the engine when necessary to place the exhaust valves in the closed position for slave piston adjustment.
13. Install the engine rocker cover. Refer to section 1.6.2 for one-piece, refer to section 1.6.3
for two-piece, and refer to section 1.6.5 for three-piece.
14. Install all remaining components that were removed for this procedure.
15. Connect starting power for the engine.
16. Verify proper Jake Brake installation by driving the vehicle, then checking engine brake performance.
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-562a
1.29
JAKE BRAKE
1.29.6
Removal of Model 790 Jake Brake Assembly
Remove the Model 790 Jake Brake as follows:
To avoid injury from hot engine surfaces, stop the engine and allow it to cool ambient temperature before working on it.
To avoid injury from accidental engine start-up, disable/disconnect power to the engine starting system.
1. With the engine at ambient temperature and power to the starting system disconnected,
Refer to section of the Series 60 Service Manual, 6SE483 and remove the engine rocker cover.
2. Note the location of the rocker arm shaft, the exhaust valve rocker arm, the fuel injector rocker arm, and the intake valve rocker arm.
3. Disconnect the solenoid wiring harness connectors from the Jake Brake solenoids.
1-562b From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
4. Remove the three (3) 140 mm long mounting bolts that secure the engine brake to the cylinder head. See Figure 1-443a.
1. Mounting Bolt — 170 mm Long
2. Mounting Bolt — 140 MM Long
Figure 1-443a
3. Stud Bolt
4.
Nut
Model 790 Jake Brake Fasteners
5. Remove the three (3) 170 mm long mounting bolts and the two (2) nuts that secure the engine brake to the cylinder head.
6. Remove the engine brake assembly.
7. Repeat steps 1 through step 5 and remove the second Jake Brake assembly from the engine.
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-562c
1.29
JAKE BRAKE
1.29.6.1
Disassembly of Model 790 Jake Brake
Instructions for disassembly of Model 790 Jake Brakes are incomplete at time of publication, but will be provided at a future date. For components of Model 790 Jake Brakes, see Figure 1-443b.
1. Solenoid Valve
3.Center Seal
4. Lower Seal
5. Master Piston
6. Master Piston Pushrod
7. Master Piston Spring
8. Retaining Ring
9.Control Valve
10. Outer Control Valve Spring
11. Inner Control Valve Spring
12. Washer
13. Retaining Ring
14.J-Lash ® Screw
15. Locknut
16. Slave Piston
17. Slave Piston Bridge
18. Outer Slave Piston Spring
19. Inner Slave Piston Spring
20. Slave Piston Spring Seat
21. Shoulder Bolt
22. Shoulder Bolt
Figure 1-443b Typical Model 790 Jake Brake Assembly
1-562d From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
1.29.7
Cleaning of Model 790 Jake Brake
Instructions for cleaning of Model 790 Jake Brake are incomplete at the time of publication, but will be provided at a future date.
1.29.8
Inspection of Model 790 Jake Brake
Instructions for inspection of Model 790 Jake Brake are incomplete at the time of publication, but will be provided at a future date.
1.29.9
Assembly of Model 790 Jake Brake
Instructions for assembly of Model 790 Jake Brake are incomplete at the time of publication, but will be provided at a future date.
1.29.10 Installation of Model 790 Jake Brake Assembly
The installation procedures for the model 790 Jake Brake assemblies differ slightly from the former engine brakes. Two brake housings are used, instead of three, and spacer bars are not required. Install the model 790 Jake Brake assemblies as follows:
1. With the engine at ambient temperature, install front Jake Brake housing (with two solenoids) over the front three cylinders. Position with solenoids on camshaft side of engine.
2. Install the rear housing (with one solenoid) over the rear three cylinders. Position with solenoid on camshaft side of engine.
NOTE:
There is one extra mounting hole drilled on the slave piston side of each housing. These holes are for manufacturing purposes only and are not used for installation.
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-562e
1.29
JAKE BRAKE
3. Install six (6) 170 mm bolts through the housings into the rocker shafts in locations 1 through 6, and install two (2) nuts in locations 7 and 8. See Figure 1-443c.
Figure 1-443c Housing Hold-Down Bolt Locations
NOTICE:
To ensure proper engine brake housing installation, Jake
Brake mounting bolts (identified by a circle "J" on the heads) and required one-piece spacers
must
be used when mounting the brake assemblies.
4. Install six (6) 140 mm bolts into each housing and through the spacers in locations
9 through 14.
5. Torque all mounting bolts to 136 N·m (100 lb-ft) in bolt location number sequence shown.
See Figure 1-443c.
6. Route the wire to the solenoid for cylinder 1 through the front retaining clip on the front housing and connect to the solenoid. Torque screw to 1.13 N·m (10 lb·in.).
7. Route wire to the solenoid for cylinders 3 and 4 through the rear retaining clip on the front housing and connect to the solenoid. Torque screw to 1.13 N·m (10 lb·in.).
8. Route wire to the solenoid for cylinders 4, 5 and 6 through the single retaining clip on the rear housing and secure to the terminal screw on the solenoid. Torque screw to 1.13
N·m (10 lb·in.).
9. Secure any excess wire to the injector harness with wire ties.
1-562f From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
1.29.10.1
Set Slave Piston Lash
The slave piston lash must be set after Jake Brake housings are installed. Adjustments must be made with the engine stopped and cold and the oil temperature at 60 C (140 F) or below. Exhaust valves on the cylinder must be in the closed position (rocker arm roller should be on the base circle of the camshaft).
NOTICE:
The slave piston adjustment procedure
must
be followed exactly. Failure to properly adjust Jake Brakes will result in inefficient engine brake performance and may lead to severe engine or Jake Brake damage.
Adjust Jake Brake Model 790 slave piston lash as follows:
1. Loosen the locknut. Then, using a 5/16 in. Allen wrench, turn the J-Lash adjusting screw counter-clockwise until a 0.660 mm (0.026 in.) feeler gauge can be inserted between the slave piston and the exhaust rocker adjusting screw. Insert the feeler gauge.
2. Using the 5/16 in. Allen wrench, turn the J-Lash adjusting screw in (clockwise) until the slave piston contacts the feeler gauge and the exhaust rocker adjusting screw. When the valve spring begins to compress, turn the screw clockwise one additional turn. Wait at
least 30 seconds for oil to be purged from the J-Lash adjusting screw. See Figure 1-443d.
1. J-Lash Adjusting Screw
2. Slave Piston
3. Exhaust Valve Spring
Figure 1-443d Turn the Adjusting Screw Until the Valve Spring Compresses
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-562g
1.29
JAKE BRAKE
NOTICE:
Oil
must
be purged from the J-Lash adjusting screw. Oil remaining in the J-Lash screw will cause inaccurate clearance adjustment, which could result in damage to the engine or Jake Brake.
If oil is below room temperature (below
16 C or 60 F), wait at least two minutes for oil to be purged from the J-Lash adjusting screw.
3. After waiting the required interval to purge oil from the J-Lash adjusting screw, back out the adjusting screw (turn counter-clockwise) only until a 0.660 mm (0.026 in.) feeler gage can be moved with a slight resistance. See Figure 1-443e. Do not back out the J-Lash
adjusting screw more than required to obtain a light drag on the feeler gage. Using the Allen wrench to hold the J-Lash adjusting screw in place, torque the lock nut to
35 N·m (25 lb-ft).
1. J-Lash Adjusting Screw
2. Locknut
3. Feeler Gage
Figure 1-443e Adjusting Slave Piston Lash
NOTE:
If the J-Lash adjusting screw is backed out until it no longer compresses the slave piston spring, oil will enter the screw and the adjustment will be incorrect. If this occurs, repeat step 1 and step 2.
1-562h From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SERIES 60 SERVICE MANUAL
4. After torquing the adjusting screw lock nut, recheck lash setting. If lash is incorrect, repeat step 1 and step 2.
NOTE:
Once the engine brake has been run, you will not be able to check Jake Brake adjustment. This is because of oil retained in the J-Lash adjusting screw. If unsure of the adjustment, you must repeat step 1 through step 3.
5. Repeat step 1 through step 3 for the remaining slave piston on the same cylinder.
6. Repeat step 1 through step 4 for the remaining cylinders.
7. Complete the installation by installing the rocker cover. Refer to section 1.6 of the service manual.
8. Install all remaining components that were removed for this procedure.
9. Connect starting power for the engine.
10. Start and drive the vehicle to verify proper Jake Brake performance.
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION From Bulletin 16-60-99 1-562i
1.29
JAKE BRAKE
1-562j From Bulletin 16-60-99
All information subject to change without notice.
6SE483 9901 Copyright © 1999 DETROIT DIESEL CORPORATION
SECTION 03: FUEL SYSTEM
CONTENTS
2. FUEL LINES AND FLEXIBLE HOSES ........................................................................................... 03-4
4. FILTERS AND WATER SEPARATOR ........................................................................................... 03-4
4.1 FUEL FILTER/WATER SEPARATOR SERVICING ................................................................. 03-4
4.2 FUEL FILTER SERVICING (PRIMARY AND SECONDARY)................................................... 03-5
4.3 DAVCO FUEL PRO 382 ........................................................................................................... 03-6
4.4 PREHEATER FUEL FILTER .................................................................................................... 03-6
5. FUEL TANK..................................................................................................................................... 03-7
5.1 TANK REMOVAL...................................................................................................................... 03-7
Fuel Tank.................................................................................................................. 03-7
Fuel
5.1.3 Transverse Fuel Tank ....................................................................................................... 03-8
5.2 TANK INSTALLATION.............................................................................................................. 03-8
5.3 FUEL TANK VERIFICATION .................................................................................................... 03-9
5.4 POLYETHYLENE FUEL TANK REPAIR .................................................................................. 03-9
9.1 PRE-CLEANER SERVICING ................................................................................................. 03-11
9.2 AIR CLEANER SERVICING ................................................................................................... 03-11
9.3 GENERAL RECOMMENDATIONS ........................................................................................ 03-11
9.4 AIR CLEANER RESTRICTION INDICATOR.......................................................................... 03-11
11. FUEL PEDAL............................................................................................................................. 03-12
11.1 FUEL PEDAL ADJUSTMENT................................................................................................. 03-12
11.2 POTENTIOMETER REPLACEMENT..................................................................................... 03-12
12. SPECIFICATIONS ..................................................................................................................... 03-13
03- 1
Section 03: FUEL SYSTEM
ILLUTRATIONS
FIGURE 1: FUEL SYSTEM SCHEMATIC ............................................................................................... 03-3
FIGURE 2: MANUAL SHUT-OFF VALVES............................................................................................. 03-4
FIGURE 3: FUEL FILTER/WATER SEPARATOR .................................................................................. 03-5
FIGURE 4: DAVCO FUEL PRO 382 FUEL FILTER ................................................................................ 03-6
FIGURE 5: 180 US GALLONSFUEL TANK (XL2-40) ............................................................................. 03-8
FIGURE 6: 208 US GAL.
MAIN FUEL TANK (XL2-45) & 90 US GAL.
AUXILIARY FUEL TANK
(OPTIONAL) (MTH 45) .................................................................................................................... 03-8
FIGURE 7: 250 US GALLONS FUEL TANKS (MAIN TANK & TRANSVERSE FUEL TANK) (MTH 40 &
MTH 45E)......................................................................................................................................... 03-9
FIGURE 8: FUEL TANK REPAIR ............................................................................................................ 03-9
FIGURE 9: PRIME PUMP SWITCH LOCATION................................................................................... 03-10
FIGURE 10: FUEL PUMP LOCATION .................................................................................................. 03-10
FIGURE 11: RESTRICTION INDICATOR............................................................................................. 03-12
FIGURE 12: ELECTRONIC FOOT PEDAL ASSEMBLY03010............................................................. 03-12
03- 2
Section 03: FUEL SYSTEM
1. FUEL SYSTEM DESCRIPTION
Figure 1 shows a schematic of the fuel system. Fuel is drawn from the fuel tank through a manual shutoff valve, a primary fuel filter or a fuel filter/water separator (optional) before it enters the fuel pump.
Leaving the pump under pressure, the fuel flows through a secondary fuel filter and a shut-off valve, then to the cylinder head. The fuel reaches the injectors in the cylinder head through passages within the head. Excess fuel exits at the rear of the head just above the inlet, through a restrictive return fitting which maintains fuel pressure in the system. Finally, the fuel flows through the check valve and the fuel cooler before it returns to the fuel tank. Three preheaters are available: 41 000 BTU, 45000 BTU or 80
000 BTU. If the vehicle is equipped with the 41 000 BTU preheater, the fuel is drawn from the tank through the fuel pump to the preheater. If the vehicle is equipped with the 45000 BTU or with the 80 000
BTU preheater, the fuel is drawn from the fuel tank through a fuel filter to the preheater. Excess fuel returns to the fuel tank.
FIGURE 1: FUEL SYSTEM SCHEMATIC
03- 3
03005
Section 03: FUEL SYSTEM
2. FUEL LINES AND FLEXIBLE HOSES
Make a visual check for fuel leaks at all enginemounted fuel lines and connections and at the fuel tank suction and return lines. Since fuel tanks are susceptible to road hazards, leaks in this area may best be detected by checking for accumulation of fuel under the tank. Engine performance and auxiliary equipment is greatly dependent on the ability of flexible hoses to transfer lubricating oil, air, coolant and fuel oil.
Diligent maintenance of hoses is an important step in ensuring efficient, economical and safe operation of engine and related equipment.
Check hoses daily as part of the pre-start-up inspection. Examine hoses for leaks and check all fittings, clamps and ties carefully. Make sure that the hoses are not resting on or touching shafts, couplings, and heated surfaces, including exhaust manifolds, any sharp edges or other obviously hazardous areas. Since all machinery vibrates and moves to a certain extent, clamps and ties can fatigue with age. To ensure continued proper support, inspect fasteners frequently and tighten or replace them as necessary. Refer to the schematic diagram of the fuel system (Fig. 1).
Caution: Oil level above the dipstick full mark or a decrease in lube oil consumption may indicate internal fuel leaks. Check oil level frequently.
Manual shut-off valves on engine fuel-supply line are located on the R.H. side of engine compartment (Fig. 2). A manual shut-off valve is located at the inlet side of the primary fuel filter
(fuel filter/water separator, if vehicle is so equipped) under the air compressor. Another manual shut-off valve is located at the outlet side of the secondary fuel filter, under the starter.
No manual valve is required on preheater fuelsupply line, since the positive-displacement fuel pump (located close to the fuel tank) prevents fuel flow when not activated.
FIGURE 2: MANUAL SHUT-OFF VALVES
03006
4. FILTERS AND WATER SEPARATOR
The fuel system is equipped with primary and secondary fuel filters for additional protection of the injectors. A fuel-filter/water-separator may be installed in primary fuel-filter location, to prevent water infiltration in engine fuel system
(Fig. 2). It should be drained periodically, or when the water separator telltale light on the dashboard illuminates. To drain, loosen positive seal drain valve below separator, and tighten after water has been flushed out.
Note: The operating conditions and cleanliness of type of fuel used determine the service intervals of the filter/water separator element and the secondary fuel filter cartridge.
4.1 FUEL FILTER/WATER SEPARATOR
SERVICING
The fuel filter/water separator is located on the starter side of the engine, below the air compressor. The water separator must be drained periodically or when the telltale light on the dashboard illuminates.
03- 4
Section 03: FUEL SYSTEM
7. Fill filter element/bowl assembly with clean diesel fuel and attach onto cover. Hand tighten an additional 1/3 to 1/2 turn after making full seal contact.
8. Open valves of the engine fuel supply line.
9. Run the engine and check for leaks.
Caution : If the water separator continuously requires draining, it is possible that water or sediment has accumulated in the fuel tank. To correct this situation, open the drain plug under the tank when the fuel gauge indicates tank is
1/4 full in order to drain any contaminant.
FIGURE 3: FUEL FILTER/WATER SEPARATOR
03025
Replace the water separator element as follows:
1. Drain the fuel filter/water separator as stated previously.
2. With engine "OFF" and engine fuel supply line valves closed; remove the filter element/bowl assembly from cover (for valve location, see "3. FUEL VALVES" in this section).
3. Separate bowl from filter element. Clean bowl and O-ring groove.
Note: Bowl is reusable, do not discard.
4. Lubricate O-ring with clean diesel fuel or motor oil and place it in bowl groove.
5. Screw new filter element onto bowl snugly by hand.
Caution: Do not use tool to tighten. Tighten by hand only.
6. Lubricate filter seal with clean diesel fuel or motor oil.
03- 5
4.2 FUEL FILTER SERVICING (PRIMARY AND
SECONDARY)
The primary and secondary fuel filters are located on the R.H. side of the engine. The primary filter is located below the air compressor, and the secondary fuel filter is below the starter. They are of a spin-on type and must be replaced every 12,500 miles (20 000 km) or once a year, whichever comes first. The primary fuel filter is equipped with a positive seal drain-valve to prevent water infiltration in engine fuel system. To drain, loosen positive seal drainvalve below filter and tighten after water has been flushed out.
A method of determining when filters are clogged to the extent that they should be changed is based on the fuel pressure at the cylinder head fuel inlet fitting and the inlet restriction at the fuel pump. In a clean system, the maximum pump-inlet restriction should not exceed 6 inches of mercury (20.3 kPa) and must not exceed 12 inches of mercury (41 kPa) with a dirty system.
At normal operating speeds and with the standard 0.080" restriction fittings, the fuel pressure at the cylinder head inlet is 50-75 psi
(345-577 kPa). Change the fuel filters whenever the inlet restriction at the fuel pump reaches 12 inches of mercury (42 kPa) at normal operating speeds. Also, change whenever the fuel pressure at the cylinder head inlet fitting falls to the minimum fuel pressure given above.
Change the filter cartridge(s) as follows:
Note: Use a suitable band wrench or filter wrench, such as J22775, to remove the filters.
Section 03: FUEL SYSTEM
1. Stop engine, shut off the engine fuel supply line valves (for valve location, See "3. FUEL
VALVES").
Unscrew and discard filters.
2. Fill new filter replacement cartridge(s) with clean fuel oil, about two thirds (2/3). Apply a thin coat of clean fuel oil on gasket.
3. Install new filters. Tighten until filter is snug against the gasket, with no side movement.
Rotate an additional 1/2 turn by hand.
4. Open engine fuel supply line valves.
Caution: Mechanical tightening of the fuel filters is not recommended and may result in seal and/or cartridge damage. Tighten the fuel filters by hand only.
5. Start the engine and check for leaks.
Note: There is a fuel system shut-off valve on the discharge side of the secondary fuel filter.
This check valve is designed to prevent fuel loss at time of filter replacement.
4.3 DAVCO FUEL PRO 382
The optional Fuel Pro 382 diesel fuel filter system consists of a permanently mounted fuel processor, a replaceable filter element, a filter element cover and collar and a fluid filter base assembly. This system is installed between the fuel tank and the fuel pump and is designed to be the only fuel filter in the fuel system. The filter serves as a water separator as well as a fuel filter.
When new, the fuel level as seen through the clear cover in the 382 filter is very low. It rises as dirt collects on the filter from the bottom up.
Restriction remains consistently low because fuel always flows through clean, new media.
Change filter when fuel level reaches the top of filter element.
Filter renewal:
1. Stop engine;
2. Drain fuel by opening the drain valve;
3. Untighten upper collar, remove cover;
4. Replace filter element;
5. Check O-Rings and components for wear;
6. Replace cover, hand tighten collar;
03- 6
7. Pour fuel up to bottom of filter element through spin off cap located on top of cover.
8. Start engine, raise rpm for 2-3 minutes, hand tighten collar again.
FIGURE 4: DAVCO FUEL PRO 382 FUEL FILTER
03032
Note : Fuel Pro 382 also accepts standard secondary spin-on fuel filters.
Environmental Notice : Diesel fuel is an environmentally hazardous product. Dispose in an environmentally friendly manner.
4.4 PREHEATER FUEL FILTER
The preheater fuel filter is installed only on vehicles with the optional 45000 BTU or 80 000
BTU preheaters. The filter is located beside the preheater, in the L.H. side rear service compartment or on the R.H. side of engine compartment. Replace the filter every 50,000 miles (80 000 km) or once a year, whichever comes first.
Section 03: FUEL SYSTEM
All XL2 series vehicles are equipped with a highdensity cross-link polyethylene fuel tank. XL2-40 coach has a capacity of 180 US gallons (681 liters) and XL2-45 coach has a capacity of 208
US gallons (787 liters). MTH 40 and MTH 45E fuel tanks have a total capacity of 250 US gallons (945 liters) while MTH 45 can be equipped with an optional 90 US gallons (341
Liters) auxiliary stainless steel tank forward of the standard 208 US gallons (787 liters) fuel tank. The main tank is located just forward of the rear baggage compartment, between the A/C condenser and evaporator. The auxiliary tank is located in the baggage compartment just forward of the main tank.
It is possible to drain both tanks through only one plug, but the other tank will not drain completely since the connecting hose is not on the bottom.
5.1.1 Main Fuel Tank
1. Open the condenser door and remove the fuel tank access panel. The rear baggage compartment fuel tank access panel may also be removed to facilitate access to components.
2. If applicable, unscrew clamps retaining L.H. side filler tube to the fuel tank, then disconnect tube and remove it.
On XL2-40 vehicles, fuel filler neck is accessible by opening a small door located amidships, on
R.H. side of vehicle. On all other vehicles, fuel filling access doors on both sides of vehicle provide direct access to filler necks; offering the added advantage of refueling from either side of vehicle.
3. Unscrew clamps retaining R.H. side filler tube to fuel tank and filler neck. Disconnect tube and remove it.
4. If applicable, unscrew preheater supply line, preheater return line, auxiliary return line and/or auxiliary return line from fuel tank connection-panel.
A pressure relief valve on the fuel tank connection-panel relieves high-pressure buildup and an overflow tube allows offset air in the tank to escape during filling. For 95% of the tank volume, 5% of tank inside space is kept filled with air with no exit opening, allowing for a fuel expansion safety margin. A drain plug, accessible from under the vehicle, is fitted at the bottom of the tank(s).
5. Unscrew engine supply and return lines from fuel tank connection-panel, identify them for reinstallation.
Note : For vehicles equipped with a transverse tank or an auxiliary tank, the two hoses joining the tanks should be disconnected.
6. Disconnect electrical wiring from tank on connection plate.
5.1 TANK REMOVAL
Warning: Park vehicle safely, apply parking brake, stop engine and set battery master switch
(es) to the OFF position before working on the vehicle.
Warning: Before removing the bolts securing the tank support to the frame, make sure the tank is supported adequately. Failure to do so could result in injury as well as damage to the tank.
Before working under an air-suspended vehicle, it is strongly recommended to support the body at the recommended jacking points.
Note: Before removal, the fuel tank should be completely drained by unscrewing the drain plug. Ensure that the container used has a capacity equal to the amount of fuel remaining in the tank(s).
7. From under the vehicle, on R.H. side, unscrew the 4 bolts (2 in front, 2 in back) retaining the tank support to the frame.
8. From under the vehicle, on the L.H. side, unscrew the 2 bolts (1 in front, 1 in back) retaining the tank support to the frame.
9. Carefully remove tank from under the vehicle.
5.1.2 Auxiliary Fuel Tank (if so equipped)
For vehicles equipped with a transverse tank or an auxiliary tank, drain it as well since it is directly connected to the main tank.
03- 7
1. Open the baggage compartment just forward of condenser compartment, disconnect the
(2) hoses previously joining the tanks.
Section 03: FUEL SYSTEM
2. From underneath vehicle, unscrew the two
(2) bolts retaining the tank strap (one on each side).
3. From inside the baggage compartment just forward of condenser compartment, slightly raise the strap and pull out auxiliary fuel tank using the same care as for the main fuel tank.
Caution : Protective cushions or rags should be placed on the baggage compartment floor to prevent it from being scratched by the fuel tank during removal.
5.1.3 Transverse Fuel Tank
1. The transverse fuel tank must be removed from R.H. side. The stainless steel panel must be removed by first removing the adhesive.
2. From underneath the vehicle, unscrew the bolt on left and right hand side securing the tank foot. Unscrew the two screws at the center of the tank then disconnect the two hoses previously joining the tanks.
3. Unscrew clamps retaining L.H. side filler tube to the fuel tank, then disconnect tube and remove it.
4. Unscrew clamps retaining R.H. side filler tube to fuel tank and filler neck. Disconnect tube and remove it.
5. Remove plastic molded panel from inside baggage compartment located forward of A/C
& Heating compartment.
6. Slide the tank out carefully.
5.2 TANK INSTALLATION
To install Main, Auxiliary and Transverse Fuel
Tanks, simply reverse the "Tank Removal" procedure.
FIGURE 5: 180 US GALLONSFUEL TANK (XL2-40) 03027
FIGURE 6: 208 US GAL. MAIN FUEL TANK (XL2-45) & 90 US GAL. AUXILIARY FUEL TANK (OPTIONAL) (MTH 45)
03028
03- 8
Section 03: FUEL SYSTEM
FIGURE 7: 250 US GALLONS FUEL TANKS (MAIN TANK & TRANSVERSE FUEL TANK) (MTH 40 & MTH 45E) 03029
5.3 FUEL TANK VERIFICATION
2. If necessary, remove fuel tank as per instructions in this section.
Inspect fuel tank from under vehicle for leaks or fuel traces. If a leak is detected, repair immediately as per "Polyethylene Fuel Tank
Repair" in this section.
3. Drill perforation with a 23/64" bit. Make sure drill hole is perfectly round.
Warning: Park vehicle safely, apply parking brake, stop engine and set battery master switch(es) to the OFF position before working on the vehicle.
4. Insert a screw (Prevost #500196) and a washer (Prévost #5001244) into anchor nut
(Prévost #500331).
5. Place assembly in drill hole. tighten screw by
10 complete turns. Refer to Fig. 7.
Before working under an air-suspended vehicle, it is strongly recommended to support the body at the recommended jacking points.
6. Apply sealant on head plug (Prévost
#507300) and seal hole with the head plug.
SCREW NYLON WASHER
5.4 POLYETHYLENE FUEL TANK REPAIR
Note : Fuel level must be lower than perforation to carry out this procedure.
Warning : Park vehicle safely, apply parking brake, stop engine and set battery master switches to the OFF position before working on the vehicle.
1. Locate perforation on fuel tank.
FUEL TANK INTERIOR
FIGURE 8: FUEL TANK REPAIR
ANCHOR NUT
03014
03- 9
Section 03: FUEL SYSTEM
6. PRIMING FUEL SYSTEM
The problem with restarting a diesel engine that has run out of fuel, is that after the fuel is exhausted from the tank, it is pumped from the primary fuel filter or the fuel filter/water separator
(if vehicle is so equipped), and sometimes partially removed from the secondary filter. This results in an insufficient fuel supply to sustain engine firing. The primary fuel filter or fuel filter/water separator and secondary filter must be free of air in order for the systems to provide adequate fuel for the injectors. When the engine runs out of fuel, the following operations must be performed before restarting:
Fill fuel tank with the recommended fuel oil. If only partial filling is possible, add a minimum of
10 gallons (38 liters) of fuel.
• If the vehicle is equipped with a Fuel Pro 382 fuel filter/water separation, pour fuel through spin on cap as per "4.3 DAVCO FUEL PRO
382".
• If the vehicle is equipped with an optional priming pump see Figure 1.
Press the priming switch, located in the engine compartment rear junction box just below the switches and cables. Start the engine and check for leaks.
FIGURE 9: PRIME PUMP SWITCH LOCATION
01037
If the vehicle is not equipped with a priming pump:
1. Unscrew the cap on the priming valve located on the secondary filter;
2. Direct fuel under pressure 25 psi (172 kPa) to the priming valve using a quick coupling;
3. Start the engine and check for leaks.
7. FUEL PUMP INSTALLATION
The fuel pump is driven off the rear of the air compressor.
FIGURE 10: FUEL PUMP LOCATION
03026
1. If removed, install inlet and outlet fittings in the cover of the fuel pump.
Note: New fittings have sealant already applied.
When reusing fittings, coat the threads lightly with Locktite Pipe Sealant, Detroit Diesel number J 26558-92, or equivalent, before installing. To prevent sealant from entering fuel system, do not apply to the first two threads of the fitting. Do not use Teflon tape or paste on the fittings.
2. Install drive coupling in drive hub of the fuel pump. Install a new gasket to the mounting flange of the pump.
3. Index the drive coupling with the drive hub on the end of the air compressor crankshaft and align the pump mounting boltholes with those in the air-compressor rear cover.
Note : When correctly positioned, the outlet fitting on the pump should be in approximately an 8 o'clock position when viewed from the rear, and the drain opening in the pump body facing down.
4. Seat the fuel pump squarely against the air compressor. Pilot the flange on the pump body, in the opening in the rear cover of the compressor. Install three mounting bolts and tighten them to 22-28 lbs•ft (30-38 N•m).
5. Connect the fuel inlet and outlet lines to the fuel pump and tighten.
6. Prime engine fuel system before starting engine to ensure pump seal lubrication and prompt engine starting.
03- 10
8. FUEL OIL SPECIFICATIONS
The quality of fuel oil used for high-speed diesel engine operation is a very important factor in
obtaining satisfactory engine performance, long engine life and acceptable exhaust emission levels. The fuel oil should meet ASTM designation D 975. Grade 1-D is recommended, however grade 2-D is acceptable.
Note: These fuel grades are very similar to grade DF-1 or DF-2 of Federal Specifications
VV-F-800. For detailed fuel recommendations, refer to publication "Engine Requirements-
Lubricating Oil, Fuel, and Filters" #7SE270 available from Detroit Diesel Distributors.
9. AIR CLEANER (DRY TYPE)
The vehicle is equipped with a dry-type replaceable element air cleaner, located in the engine compartment. Access the air cleaner through the engine R.H. side door. Engine air enters the air cleaner through (2) two intake ducts located just above engine side doors. It then flows through a pre-cleaner and finally through the air cleaner. The pre-cleaner removes dust and moisture by means of a discharge tube at the bottom of the element. It is in series with a replaceable impregnated paper filter element (air cleaner).
9.1 PRE-CLEANER SERVICING
The pre-cleaner is designed to be self-cleaning ; however, it should be inspected and any accumulated foreign material removed during the periodic replacement of the impregnated paper filter element.
9.2 AIR CLEANER SERVICING
Stop the engine, open the R.H. side engine compartment door, and loosen the wing nut retaining the air cleaner element to the air cleaner. Remove the element by pulling on the handle in the center of the air cleaner element.
Install cleaner element as follows:
1. Inspect the gasket-sealing surface inside the air cleaner. It must be smooth, flat and clean;
2. Install the air cleaner element;
3. Make sure that the element seals securely;
4. Inspect element cover gasket and replace if necessary.
Whenever it becomes necessary to remove the air cleaner assembly (dry type) for maintenance or other repair in this area, great care should be taken when installing air cleaner assembly.
03- 11
Section 03: FUEL SYSTEM
The pre-filter should be installed snugly in the air duct and clamped tightly to the air cleaner inlet to prevent any dust infiltration into the air cleaner.
9.3 GENERAL RECOMMENDATIONS
The following maintenance procedures will ensure efficient air cleaner operation:
1. Keep the air cleaner housing tight on the air intake pipe;
2. Make sure the correct filters are used for replacement;
3. Keep the air cleaner properly assembled so the joints are air-tight;
4. Immediately repair any damage to the air cleaner or related parts;
5. Inspect, clean or replace the air cleaner or elements as operating conditions warrant.
Whenever an element has been removed from the air cleaner housing the inside surface of the housing must be cleaned with a soft clean cloth;
6. Periodically inspect the entire system. Dustladen air can pass through an almost invisible crack or opening which may eventually cause damage to an engine;
7. Never operate the engine without an element in the air cleaner assembly;
Caution : Do not ignore the Warning given by the air restriction indicator. This could result in serious engine damage.
8. Store new elements in a closed area free from dust and possible damage.
9.4 AIR CLEANER RESTRICTION INDICATOR
A resettable restriction indicator may be installed on the engine air-intake duct, clearly visible from the rear engine compartment. The indicator monitors the vacuum level between the air filter and the engine. A red marker is displayed when the air filter is clogged and must be replaced.
Reset by pressing on the indicator's extremity.
Section 03: FUEL SYSTEM
FIGURE 11: RESTRICTION INDICATOR
01052
The fuel cooler serves to cool the surplus diesel fuel after it has exited the cylinder head, on its way back to the fuel tank. It is accessible through the engine radiator door, and it is located just in front of the coolant radiator.
REPLACEMENT
1. Disconnect cable harness connector.
Caution: Note the routing and clamping locations of the cable before disassembly.
Proper cable routing and fastening is critical to the operation of this system. Marking the foot pedal assembly to record cable routing is recommended.
Loosen the two screws and remove potentiometer. Retain for re-assembly.
3. Discard potentiometer (Fig. 12).
Position new potentiometer. Press potentiometer onto the potentiometer shaft, matching cutouts in shaft to drive tangs of potentiometer. Apply hand pressure until potentiometer has bottomed out in housing.
Reinstall screws (Fig. 12) and tighten just enough to secure potentiometer lightly. Tighten screws to 10 - 20 lbf•in (1.5 - .2 N•m).
5. Reconnect electronic foot pedal assembly's cable harness to the ECM connector. If potentiometer calibration is necessary (see
"FUEL PEDAL ADJUSTMENT" in this section).
Caution: Make sure the cable harness is routed correctly, and securely installed so that it does not become pinched, stretched, or otherwise damaged during vehicle operation.
The EFPA (Electronic Foot Pedal Assembly) connects the accelerator pedal to a potentiometer (a device that sends an electrical signal to the ECM, which varies in voltage, depending on how far down the pedal is depressed). The EFPA is installed in the space normally occupied by a mechanical foot pedal. It has maximum and minimum stops that are built into the unit during manufacturing.
11.1 FUEL PEDAL ADJUSTMENT
The EFPA contains a throttle position sensor that varies the electrical signal sent to the ECM.
The sensor must be adjusted whenever an
EFPA is serviced. In addition, the sensor should be adjusted any time codes 21 and 22 are flashed.
With the ignition "ON" and the proper diagnostic tool (DDR) (for information regarding the DDR, see "01 ENGINE" in this manual), check the throttle counts at idle and full throttle positions.
Proper pedal output should be 20/30 counts at idle and 200/235 at full throttle. If adjustment is necessary, remove the potentiometer retaining screws and rotate the potentiometer clockwise to increase counts or counterclockwise to decrease. When correct output is confirmed, tighten retaining screws.
03- 12
FIGURE 12: ELECTRONIC FOOT PEDAL ASSEMBLY 03035
Section 03: FUEL SYSTEM
12. SPECIFICATIONS
Davco FuelPro 382 Fuel Filter / Water Separator Element
Supplier number .....................................................................................................................................23521528
Prévost number ..........................................................................................................................................531437
Primary Fuel Filter / Water Separator (optional)
(May be used instead of primary filter (never use with a primary filter).
Make ............................................................................................................................................................. Racor
Type ........................................................................................................................................................... Spin-on
ELEMENT
Supplier number ......................................................................................................................................... S 3202
Prévost number ..........................................................................................................................................531390
BOWL
Supplier number ......................................................................................................................................RK30051
Prévost number ..........................................................................................................................................531389
DRAIN VALVE AND SEAL
Supplier number ......................................................................................................................................RK30058
Prévost number ..........................................................................................................................................531397
O-RING
Supplier number ......................................................................................................................................RK30076
Prévost number ..........................................................................................................................................531398
PROBE/WATER SENSOR
Supplier number ......................................................................................................................................RK21069
Prévost number ..........................................................................................................................................531391
Primary Fuel Filter
Make ..................................................................................................................................................................AC
Type ........................................................................................................................................................... Spin-on
Filter No. .....................................................................................................................................................T-915D
Service Part No. .....................................................................................................................................25014274
Prévost number ..........................................................................................................................................510137
OR
Service Part No (Type with Water Separator).......................................................................................23512317
Prévost number ..........................................................................................................................................531407
Element torque ......................................................................................................... 1/2 turn after gasket contact
Secondary Fuel Filter
Make ..................................................................................................................................................................AC
Type ........................................................................................................................................................... Spin-on
Filter No. .....................................................................................................................................................T-916D
Service Part No. .....................................................................................................................................25014342
Prévost number ..........................................................................................................................................510128
Element torque ......................................................................................................... 1/2 turn after gasket contact
Fuel tank(s) Capacity (ies)
03- 13
Section 03: FUEL SYSTEM
Standard (XL2-40).......................................................................................................180 US gallons (681 liters)
Standard (XL2-45 & MTH 45) .....................................................................................208 US gallons (787 liters)
Standard (MTH 40 & MTH 45E) .................................................................................250 US gallons (945 liters)
Optional (MTH 45).........................................................................................................90 US gallons (341 liters)
Air Cleaner
Make ........................................................................................................................................................... Nelson
Prevost Number .........................................................................................................................................530206
Service Part No ........................................................................................................................................ 7182 8N
Supplier number (element cartridge) ........................................................................................................ 70337N
Prévost number (element cartridge) ..........................................................................................................530197
Air Cleaner Restriction Indicator
Make ..................................................................................................................................................... Donaldson
Model .................................................................................................................................................RBX00-2220
Indicates .........................................................................................................................at 20" (508 mm) of water
Prévost number ..........................................................................................................................................530161
Preheater Fuel Filter (45 000 BTU or 80 000 BTU)
Make ........................................................................................................................................................ Webasto
Supplier number ........................................................................................................................................603.359
Prévost number ..........................................................................................................................................871037
Preheater Line Fuel Pump (41 000 BTU)
Make ............................................................................................................................................................. Espar
Supplier number .........................................................................................................................25-1571-45-0000
Prévost number ..........................................................................................................................................870973
Fuel Cooler
Make ..................................................................................................................................................... Berendsen
Supplier number ...................................................................................................................................... DB-1240
Prévost number ..........................................................................................................................................950109
03- 14
SECTION 04 : EXHAUST SYSTEM
CONTENTS
1. DESCRIPTION ...................................................................................................................................4-2
2. MAINTENANCE .................................................................................................................................4-2
3. MUFFLER REMOVAL & INSTALLATION .......................................................................................4-4
5. HEAT BLANKETS (CONVERTED VEHICLES ONLY) .....................................................................4-4
5.1 EXHAUST....................................................................................................................................4-4 on XL2-45 Shells................................................................................................4-4
5.1.2 Installation on XL2-40 & XL2-45E Shells .............................................................................4-5
5.2 TURBO (ALL SHELLS)................................................................................................................4-5
ILLUSTRATIONS
FIGURE 1: EXHAUST SYSTEM XL2-40 & 45E (COACH & SHELL) INSTALLATION.............................4-2
FIGURE 2: EXHAUST SYSTEM XL2-45 (COACH & SHELL) INSTALLATION .......................................4-3
FIGURE 3: FLEXIBLE TUBE INSTALLATION ...........................................................................................4-4
FIGURE 4: EXHAUST BLANKET INSTALLATION ....................................................................................4-4
FIGURE 5: LACING WIRE INSTALLATION...............................................................................................4-5
FIGURE 6: TURBO BLANKET INSTALLATION ........................................................................................4-5
4 - 1
Section 04: EXHAUST SYSTEM
1. DESCRIPTION
The muffler is rubber mounted on the vehicle frame. This feature reduces the transmission of vibrations to the muffler thus resulting in extended life of muffler, brackets and other components.
2. MAINTENANCE
The exhaust system should be inspected periodically for restrictions and leaks. The exhaust systems are shown on figures 1 & 2 (fig. 1 = XL2-40 & 45E and fig. 2 = XL2-45). Restrictions such as kinked or crimped pipes result in excessive back pressure that can lead to increased fuel consumption, power loss, and possible damage to engine combustion chamber components. Exhaust leaks are commonly the result of loose clamp bolts, corroded pipes, or a punctured muffler. In addition to objectionable noise, a leaking exhaust system could allow toxic gases to enter the vehicle. Inspect the exhaust system as follows :
• At vehicle inspection intervals ;
• Whenever a change is noticed in the sound of the exhaust system ; and
• Whenever the exhaust system is damaged.
Replace damaged or corroded exhaust system components without delay.
When operating the engine in a service garage or in a closed area, the exhaust must be vented to the outside. Place the shop vent hose over the exhaust outlet pipe.
Warning: Avoid breathing exhaust gases since they contain carbon monoxide which is odorless and colorless but harmful. Carbon monoxide is a dangerous gas that can cause unconsciousness and can be lethal. If, at any time you suspect that exhaust fumes are entering the vehicle, locate and correct the cause(s) as soon as possible.
FIGURE 1: EXHAUST SYSTEM - XL2-40 & 45E (COACH & SHELL) INSTALLATION
4 - 2
04004
Section 04: EXHAUST SYSTEM
FIGURE 2: EXHAUST SYSTEM - XL2-45 (COACH & SHELL) INSTALLATION
4 - 3
04005
Section 04: EXHAUST SYSTEM
3. MUFFLER REMOVAL &
INSTALLATION
Warning: Make sure that muffler and components are cold before handling.
1. Remove bolts and clamps securing exhaust pipe bellows to the muffler.
2. Support the muffler from underneath vehicle.
3. Remove U-clamp retaining the tail pipe to the muffler.
4. Remove bolt holding the tail pipe to the frame bracket.
5. Remove the tail pipe.
6. Remove the fasteners holding the four rubber mounts to the frame brackets.
7. Remove the fasteners securing the rubber mounts to the muffler brackets.
8. Remove rubber mounts then muffler from underneath vehicle.
9. Remove parts which are attached to the muffler such as brackets and collar.
10. Inspect and replace parts if necessary.
Reinstall parts on the new muffler.
For installation, reverse the removal procedure.
Warning: Check connections for tightness and fasteners for proper assembly.
4. FLEXIBLE TUBE INSTALLATION
The flexible exhaust tube contains an inside rigid pipe. To allow appropriate flexibility for assembly, make sure that the rigid pipe is concentric to the flexible part.
To maintain the pipe centered at the time of installation, cardboard spacers must be inserted at four places at equal distance around tubing
(Fig. 3). These spacers may be left in place and will deteriorate over time.
FIGURE 3: FLEXIBLE TUBE INSTALLATION
04003
(CONVERTED VEHICLES ONLY)
5.1 EXHAUST
5.1.1 Installation on XL2-45 Shells
1. Open L.H. side rear service compartment door, then working from inside compartment, cover bellows and exhaust pipe with blanket #040507 (Fig. 4). Position blanket so its recess is facing square tubing.
Note: If access from L.H. side rear service compartment is limited, remove engine access panel from inside vehicle then work from this area.
FIGURE 4: EXHAUST BLANKET INSTALLATION
01034
4 - 4
2. Form and compress blanket always working towards seams. Use temporary ties to position and hold blanket for forming, then shoelace for length of blanket using wire
#509754 (fig. 5 shows typical installation).
Perform a single loose wrap on each capstan. Align the small hole provided in the blanket with the exhaust port fitted on the exhaust pipe.
Section 04: EXHAUST SYSTEM
3. Form and compress blanket always working towards seams. Use temporary ties to position and hold blanket for forming, then shoelace for length of blanket using lacing wire #509754 (see figure 5 showing typical installation). Perform a single loose wrap on each capstan. Align the small hole provided in the blanket with the exhaust port fitted on the exhaust pipe.
Caution: Ensure radiator fan does not touch the exhaust blanket.
5.2 TURBO (ALL SHELLS)
Attach a section of lacing wire #509754 to both upper capstans of turbo blanket #040505, then cover turbine housing (Fig. 6). Attach upper capstans with lower capstans to secure blanket in place.
FIGURE 5: LACING WIRE INSTALLATION
01035
3. Install the turbo blanket as described further in this section.
5.1.2 Installation on XL2-40 & XL2-45E
Shells
1. Working from inside vehicle, locate engine access panel located at rear of vehicle (just over engine), unscrew bolts (4 or 6) retaining panel then remove.
2. Cover bellows and exhaust pipe with blanket
#040511. Position blanket so its recess is facing radiator shroud & fan. Refer to figure
4 showing installation on XL2-45 vehicles; on this model, the blanket is not provided with a recess since the clearance between radiator fan and exhaust pipe is sufficient.
Note: It may be necessary to work from under the vehicle to install the blanket lower section.
FIGURE 6: TURBO BLANKET INSTALLATION 01036
Note: The compressor housing does not require a blanket.
4 - 5
SECTION 05: COOLING SYSTEM
CONTENTS
1. DESCRIPTION .................................................................................................................................05-3
2. MAINTENANCE ...............................................................................................................................05-4
2.1 VEHICLES WITHOUT COOLANT FILTERS .............................................................................05-4
2.2 VEHICLES WITH COOLANT FILTERS.....................................................................................05-4
3. HOSES .............................................................................................................................................05-5
3.1 CONSTANT-TORQUE HOSE CLAMPS ...................................................................................05-5
3.1.1 Installation ..........................................................................................................................05-5
3.1.2 Maintenance.......................................................................................................................05-5
4. COOLANT ........................................................................................................................................05-6
4.1 COOLANT LEVEL VERIFICATION ...........................................................................................05-6
4.2 COOLANT LEVEL SENSOR .....................................................................................................05-6
4.3 THAWING COOLING SYSTEM.................................................................................................05-6
4.4 COOLANT REQUIREMENTS ...................................................................................................05-6
4.5 COOLING SYSTEM RECOMMENDATIONS...............................................................................05-6
4.6 INHIBITORS ..............................................................................................................................05-7
Test Procedures ...................................................................................................05-7
4.7 COOLANT RECOMMENDATIONS...........................................................................................05-7
Without Coolant Filters ........................................................................................05-8
With Coolant Filters .............................................................................................05-8
7. FLUSHING......................................................................................................................................05-10
7.1 COOLING SYSTEM DESCALERS..........................................................................................05-10
7.2 REVERSE FLUSHING ............................................................................................................05-10
9. RADIATOR .....................................................................................................................................05-12
9.1 MAINTENANCE.......................................................................................................................05-12
10. VARIABLE SPEED RADIATOR FAN ........................................................................................05-12
10.1 MAINTENANCE.......................................................................................................................05-12
10.2 INSPECTION...........................................................................................................................05-13
10.3 THERMOSTAT OPERATION..................................................................................................05-13
11.1 MAINTENANCE.......................................................................................................................05-13
11.2 OIL CHANGE...........................................................................................................................05-13
12. RADIATOR FAN BELT REPLACEMENT..................................................................................05-14
12.1 BELT TENSION ADJUSTMENT..............................................................................................05-14
14. SPECIFICATIONS ......................................................................................................................05-16
05- 1
Section 05: COOLING SYSTEM
ILLUSTRATIONS
FIGURE 1: COOLING SYSTEM ............................................................................................................05-3
FIGURE 2: SURGE TANK ENGINE COMP'T ........................................................................................05-4
FIGURE 3: CONSTANT-TORQUE CLAMP ............................................................................................05-5
FIGURE 4: SURGE TANK SIGHT GLASS...............................................................................................05-6
FIGURE 5: HEATER LINE SHUT-OFF VALVE........................................................................................05-8
FIGURE 6: ENGINE COMPARTMENT ....................................................................................................05-8
FIGURE 7: HEATER LINE SHUT-OFF VALVES .....................................................................................05-9
FIGURE 8: ENGINE COOLANT DRAIN COCKS ...................................................................................05-9
FIGURE 9: WATER PUMP DRAIN COCK ...............................................................................................05-9
FIGURE 10: COOLANT FILTER ............................................................................................................05-11
FIGURE 11: MECHANICAL LOCKING DEVICE ................................................................................05-12
FIGURE 12: THERMOSTAT AND RELATED PARTS ..........................................................................05-13
FIGURE 13: FAN GEARBOX ...............................................................................................................05-13
FIGURE 14: PRESSURE RELEASING VALVE .....................................................................................05-14
FIGURE 15: REGULATOR VALVE ........................................................................................................05-14
FIGURE 16: BELT TENSIONER.............................................................................................................05-14
FIGURE 17: ANGLE SUPPORT ............................................................................................................05-15
FIGURE 18: PULLEY ALIGNMENT .......................................................................................................05-15
FIGURE 19: PULLEY VERTICAL ANGLE .............................................................................................05-15
05-2
Section 05: COOLING SYSTEM
1. DESCRIPTION
A radiator and thermo-modulated fan are used to effectively dissipate the heat generated by the engine.
A centrifugal-type water pump is used to circulate the engine coolant (Fig. 1).
Two full blocking-type thermostats are used in the water outlet passage to control the flow of coolant, providing fast engine warm-up and regulating coolant temperature.
The engine coolant is drawn from the lower portion of the radiator by the water pump and is forced through the oil cooler and into the cylinder block. For vehicles with automatic transmissions, the coolant circulates in the transmission cooler before going through the oil cooler and the cylinder block.
FIGURE 1: COOLING SYSTEM
From the cylinder block, the coolant passes up through the cylinder head and, when the engine is at normal operating temperature, it goes through the thermostat housing and into the upper portion of the radiator. The coolant then passes through a series of tubes where its heat is dissipated by air streams created by the revolving fan and the motion of the vehicle.
05-3
05075
Upon starting a cold engine or when the coolant is below normal operating temperature, the closed thermostats direct coolant flow from the thermostat housing through the by-pass tube to the water pump. Coolant is recirculated through the engine to aid engine warm up. When the thermostat opening temperature is reached, coolant flow is divided between the radiator inlet
Section 05: COOLING SYSTEM and the by-pass tube. When the thermostats are completely open, all of the coolant flow is to the radiator inlet.
FIGURE 2: SURGE TANK - ENGINE COMP'T 05079
The cooling system is filled through a filler cap on the surge tank (Fig. 2). A pressure cap on top of surge tank or underneath later is used to maintain pressure within the system. When system exceeds normal pressure rating (14 psi -
96.53 kPa), the cap releases air and if necessary, coolant through the overflow tube
(Fig. 2). Two thermostats are located in the housing attached to the right side of the cylinder head (Fig. 1). Furthermore, a water temperature sensor mounted on the cylinder head (radiator side) is also supplied for engine protection purposes.
The engine cooling system also provides hot coolant fluid for the vehicle heating system. Refer to section 22, "”HEATING AND AIR
CONDITIONING" in this manual for information relating to heating system water circulation.
2. MAINTENANCE
A systematic routine inspection of cooling system components is essential to ensure maximum engine and heating system efficiency.
• Check coolant level in the surge tank daily, and correct if required. Test antifreeze strength.
• Maintain the prescribed inhibitor strength levels as required. Coolant and inhibitor concentration must be checked at each oil change, every 12,500 miles (20 000 km) or
05-4 once a year, whichever comes first to ensure inhibitor strength. For vehicles equipped with coolant filters replace precharge element filter with a maintenance element filter as per
“COOLANT FILTER” in this section. If the vehicle is not equipped with a filter, add the recommended inhibitor concentration to the antifreeze/water solution.
• Drain, flush, thoroughly clean and refill the system every two years or every 200,000 miles (320 000 km), whichever comes first.
For vehicle equipped with coolant filters, change the precharge element filter or the existing maintenance element filter for a new maintenance element filter. If the vehicle is not equipped with filters add the recommended inhibitor concentration to the antifreeze/water solution.
Note: Do not add inhibitors to the antifreeze / water solution if vehicle is equipped with a coolant filter.
Coolant must be discarded in an environmentally safe manner.
2.1 VEHICLES WITHOUT COOLANT FILTERS
Refer to Nalcool 3000 with Stabil-Aid bulletin annexed to the end of this section for preventive maintenance (at each oil change) and initial treatment instructions (each time the cooling system is drained and flushed).
2.2 VEHICLES WITH COOLANT FILTERS
Change the coolant precharge element filter for a maintenance element filter at initial oil change
(see "Specifications" at the end of this section) and replace existing maintenance element filter with a new one as per "COOLANT FILTER" in this section. A precharge element filter must be installed each time the cooling system is drained and flushed prior to installing a maintenance element filter.
• Check belts for proper tension; adjust as necessary and replace any frayed or badly worn belts.
• Check radiator cores for leaks and make sure the cores are not clogged with dirt or insects. To avoid damaging the fins, clean cores with a low-pressure air hose. Steam clean if required.
• Inspect the water pump operation. A leaky pump sucks in air, increasing corrosion.
• Repair all leaks promptly. Unrepaired leaks can lead to trouble. Inspect and tighten radiator mounts periodically. Test and replace thermostats regularly.
Note: In order to ensure the integrity of the system, it is recommended that a periodic cooling system pressure check be made.
Pressurize the cooling system to 103-138 kPa
(15-20 psi) using Radiator and Cooling System
Tester, J24460-1. Do not exceed 138 kPa (20 psi).
Any measurable drop in pressure may indicate a leak. Whenever the oil pan is removed, the cooling system should be pressure checked as a means of identifying any incipient coolant leaks. Make sure the cause of the internal leak has been corrected before flushing the contaminated system.
Leaks at the thermostat housing hose connections may be caused by deformation of connections or by rough surfaces on the castings of the hose mounting surfaces. It is recommended that "Dow Corning RTV-102
Compound" or any equivalent product be applied on cast surfaces prior to hose installation.
Caution: Castings should be clean and free of oil and grease before applying compound. No other sealer should be used with RTV-102 compound.
3. HOSES
Rotten, swollen, and worn out hoses or loose connections are frequent causes of cooling system problems.
Serious overheating is often caused by an old hose collapsing or from rotten rubber shedding from hoses and clogging the coolant passages.
Connections should be inspected periodically and hose clamps tightened. Replace any hose found to be cracked or swollen.
When installing a new hose, clean pipe connections and apply a thin layer of a non-hardening sealing compound. Replace worn out clamps or clamps that pinch hoses.
Section 05: COOLING SYSTEM
3.1 CONSTANT-TORQUE HOSE CLAMPS
All hose clamps of 1 3/8" ID and over, used on the heating and cooling systems, are of the
"Constant-torque" type. These clamps are worm-driven, made of stainless steel, and supplied with a series of Belleville spring washers. They also feature an extended integral liner that covers the band slots to protect soft/silicone hoses from damage, and help maintain consistent sealing pressure.
This type of clamp is designed to automatically adjust its diameter to compensate for the normal expansion/contraction of a hose and metal connection that occurs during vehicle operation and shutdown. The constant-torque clamp virtually eliminates coolant losses due to "Cold flow" leakage and greatly minimizes clamp maintenance.
3.1.1 Installation
A torque wrench should be used for proper installation. The recommended torque is 90 to
100 lbf·in. (10 to 11 N·m). The Belleville spring washer stacks should be nearly collapsed flat and the screw tip should extend ¼" (6 mm) beyond the housing (Fig. 3).
FIGURE 3: CONSTANT-TORQUE CLAMP 05037
Caution: The hose clamps will break if overtorqued. Do not over-tighten, especially during cold weather when hose has contracted.
3.1.2 Maintenance
The constant-torque clamps contain a "Visual torque check “ feature. When the tip of the screw is extending ¼" (6 mm) out of the housing, the clamp is properly installed and maintains a leak-proof connection. Since the constant-torque clamp automatically adjusts to keep a consistent sealing pressure, there is no need to re-torque hose clamps on a regular basis. During vehicle operation and shutdown, the screw tip will adjust according to the temperature and pressure
05-5
Section 05: COOLING SYSTEM changes. Checking for proper torque should be done at room temperature.
4. COOLANT
4.1 COOLANT LEVEL VERIFICATION
Coolant level is correct when cold coolant is visible through the surge tank sight glass
(Fig. 4). If coolant level is low, fill cooling system.
FIGURE 4: SURGE TANK SIGHT GLASS
05080
4.2 COOLANT LEVEL SENSOR
This warning device consists of a fluid level probe mounted on the surge tank. The probe sends a signal to the ECM to indicate coolant level. If the coolant level drops below the probe, the "Check Engine" light flashes and a diagnostic code is registered (see section 01 "
ENGINE" ).
Caution: Do not run engine with the “Check
Engine” light flashing.
The level probe is mounted on the R.H. side of the surge tank while the electronic module is mounted inside the rear electric junction box.
4.3 THAWING COOLING SYSTEM
If the cooling system becomes frozen solid, place the coach in a warm area until the ice is completely thawed. Under no circumstances should the engine be operated when the cooling system is frozen, as it will result in engine overheating due to insufficient coolant.
05-6
Once thawed, check engine, radiator and related components for damage caused by expansion of frozen coolant fluid.
4.4 COOLANT REQUIREMENTS
The coolant provides a medium for heat transfer and controls the internal temperature of the engine during operation. In an engine having proper coolant flow, some of the combustion heat is conveyed through the cylinder walls and the cylinder head into the coolant. Without adequate coolant, normal heat transfer cannot take place within the engine, and engine temperature rapidly rises. Coolant must therefore be carefully selected and properly maintained.
Select and maintain coolant in order to meet the following basic requirements:
• Provide for adequate heat transfer.
• Provide protection from cavitation damage.
• Provide a corrosion and erosion resistant environment within the cooling system.
• Prevent formation of scale or sludge deposits in the cooling system.
• Be compatible with the cooling system hose and seal materials.
• Provide adequate freeze protection during cold weather operation.
Combining suitable water with reliable inhibitors satisfies the first five requirements. When freeze protection is required, a solution of suitable water and antifreeze containing adequate inhibitors will provide a satisfactory coolant fluid.
Ethylene glycol-based antifreeze is recommended for use in Series 60 engines. The cooling system capacity is 24 US gal (91 liters).
Note: In general, antifreeze does not contain adequate inhibitors. For this reason, supplemental coolant additives are required.
For a complete overview of engine coolants used with Detroit Diesel Engines, refer to
"Specifications" in the Detroit Diesel Series 60
"Engine Operator's Guide" .
4.5 COOLING SYSTEM RECOMMENDATIONS
Always maintain cooling system at the proper coolant level. Check daily.
Section 05: COOLING SYSTEM
The cooling system must be pressurized to prevent localized boiling of coolant. The system must be kept clean and leak-free. The filler and pressure caps must be checked periodically for proper operation.
4.6 INHIBITORS
A coolant solution, which has insufficient inhibitors or no inhibitors at all, invites the formation of rust, scale, sludge and mineral deposits within the cooling system. These deposits can cause water pump seal wear and coat the interior of coolant system passages.
Heat transfer is reduced as deposits build up, leading to an overheating condition. Continued operation with this condition can lead to serious engine damage: liner scuffing, scoring, piston seizure and cylinder head cracking. These damages can occur quickly or over a longer period of time, depending of location and amount of deposits. Improperly inhibited coolants can become corrosive enough to "eat away" coolant passages and seal ring grooves and cause leaks to develop. Hydrostatic lock can occur if leak is internal and accumulates on top of a piston. The result may be a bent connecting rod. Cavitation erosion may occur in improperly inhibited coolants. Cavitation erosion is caused by the implosion of tiny bubbles against localized surfaces of the system. Such implosion causes pinpoint pressures high enough to erode pump impellers, cylinder liners and cylinder blocks. In extreme cases, their surfaces are so deeply pitted that they appear to be spongy, and holes can develop completely through them.
4.6.1 Inhibitor Test Procedures
Test Kits are commercially available to check engine coolant for nitrite concentration. Nitrite concentration is an indication of Supplemental
Coolant Additive (SCA) level. Nitrite must be maintained within recommended levels. Coolant must be tested at each oil change to insure that inhibitor levels are maintained within the ranges shown below:
Detroit Diesel Selected Products System
Boron (B)
Nitrite (NO2)
Min. PPM Max PPM
1000
800
1500
2400
05-7
Nitrates (NO3)
Silicon (Si)
Phosphorous (P)
1000
50
300
2000
250
500
Note : Above SCA values with GM6038-M or
ASTM 4985. Use Nalco Chemical Company nitrite test kits (CO-318). A factory coolant analysis program is available through Detroit
Diesel distributors under part number 23508774.
4.7 COOLANT RECOMMENDATIONS
Always use recommended antifreeze, inhibitor and water at proper concentration levels. A 50% coolant/water solution is normally used as factory fill. Antifreeze concentration over 70% is not recommended because of poor heat transfer capability, adverse freeze protection and silicate dropout. Antifreeze concentration below 30% offers little freeze, boilover or corrosion protection.
2. Use only ethylene glycol antifreeze meeting the GM 6038-M or ASTM D 4985 formulation or an equivalent antifreeze with a 0.15% maximum silicate content meeting GM 1899-
M performance specifications.
3. Use an antifreeze solution year-round for freeze and boil-over protection. Seasonal changing of coolant from an antifreeze solution to an inhibitor/water solution is recommended.
4. Pre-mix coolant makeup solutions at proper concentrations before adding to the cooling system.
5. Maintain the prescribed inhibitor strength levels as required.
6. Do not mix different base inhibitor packages.
7. Always maintain proper coolant level.
Caution: Always test the solution before adding water or antifreeze.
8. If cooling system is not at the proper protection level. Mix coolant/water solution to the proper concentration before adding to the cooling system
9. Use only non-chromate inhibitors.
10. Distilled water is recommended.
Section 05: COOLING SYSTEM
DO NOT USE THE FOLLOWING:
• Soluble
• Chromate
• Methoxy propanol-base antifreeze
• Methyl alcohol-base antifreeze
• Sealer additives or antifreezes containing sealer additives
Warning: Never remove filler cap while coolant is hot. When coolant is at ambient temperature, release pressure from system by turning the pressure cap counterclockwise 1/4 turn; then remove filler cap slowly. A sudden release of pressure from the heated cooling system can result in severe burns from the expulsion of hot coolant fluid.
4.7.1 Vehicles Without Coolant Filters
Refer to Nalcool 3000 with Stabil-Aid bulletin annexed to the end of this section for preventive maintenance (at each oil change) and initial treatment instructions (each time the cooling system is drained and flushed).
FIGURE 5: HEATER LINE SHUT-OFF VALVE 05070
Another valve is located in the engine compartment under the radiator fan gearbox
(Fig. 6).
Note : Refer to section 22 under "Preheating
System" for information about preheater access and heater line shutoff valve.
4.7.2 Vehicles With Coolant Filters
Change the coolant precharge element filter for a maintenance element filter at initial oil change
(see Specifications at the end of this section) and replace existing maintenance element filter with a new one as per "COOLANT FILTER" in this section. A precharge element filter must be installed each time the cooling system is drained and flushed before installing a maintenance element filter.
Note: The coolant filter contains inhibitors.
5. DRAINING COOLING SYSTEM
Use the following procedures to drain the cooling system partially or completely.
To drain engine and related components:
1. Stop engine and allow engine to cool. Close both heater line shutoff valves.
On XL2-40 & 45E vehicles , the valves are located in engine compartment. One is on the
R.H. side of compartment and is accessible through engine compartment R.H. side door (Fig.
5).
05-8
FIGURE 6: ENGINE COMPARTMENT 05078
On XL2-45 vehicles , the valves are located in the engine compartment, on the L.H. side of engine and are accessible through L.H. side rear service compartment (Fig. 7).
Section 05: COOLING SYSTEM
FIGURE 7: HEATER LINE SHUT-OFF VALVES
05067
Warning: Before proceeding with the following steps, make sure the coolant has cooled down.
The sudden release of pressure from a heated cooling system can result in loss of coolant and possible personal injury (scalding) from the hot liquid.
2. Unscrew the surge tank pressure cap counterclockwise, ¼ turn to let air enter the system and permit the coolant to drain completely from system.
FIGURE 8: ENGINE COOLANT DRAIN COCKS 05074
3. Open the water pump housing inlet line drain cock (Fig. 9).
FIGURE 9: WATER PUMP DRAIN COCK
05072
4. Open drain cock at bottom of thermostat housing to drain the coolant trapped above the thermostats (1, Fig. 8).
5. Open the radiator drain cock (Fig. 6).
6. Open engine drain cock (2, Fig. 8).
7. Remove the transmission oil cooler. Drain, flush and inspect. Refer to Section 7,
“TRANSMISSION” for oil cooler maintenance or preventive replacement.
Caution: Drain water pump completely before extended storage to avoid possible water pump damage.
Caution: If freezing weather is anticipated and the engine is not protected with antifreeze, drain the cooling system completely when vehicle is not in use. Trapped water in the cylinder block, radiator or other components may freeze and expand resulting in damages. Leave the drain plugs open until the cooling system can be filled with coolant fluid. Do not run engine with cooling system empty.
To drain the entire system, do the previous steps while maintaining the shutoff valves in the open position; then follow the procedure under
“9.2 Draining Heating System” in Section 22.
6. FILLING COOLING SYSTEM
If only the engine and related components were drained, maintain the two heater line shutoff valves in their closed position, then proceed as follows.
05-9
Section 05: COOLING SYSTEM
1. Close all drain cocks. Refer to draining procedure for the location of draining points.
2. Refill cooling system from the surge tank filler cap inlet with a recommended ethylene glycol-based antifreeze and water solution of the required concentration. Add Detroit
Diesel selected product cooling system inhibitors (if required).
Note: The coolant level should remain within two inches of the surge tank filler neck.
Note: Make sure the vent line at top of thermostat housing is properly connected and not obstructed. The vent line (thermostat housing dome to radiator top tank) is required to ensure complete engine fill and proper venting of air in the system.
3. Install the filler and pressure caps, then start the engine and run it at fast idle until reaching normal operating temperature.
Check for leaks.
Note: If for any reason, the coolant level drops below the surge tank level probe, the Check
Engine light will flash.
4. Stop engine and allow to cool.
5. Open the two heater line shutoff valves, check the coolant level in the surge tank, and then add as required.
Caution: Never pour cold coolant into a hot engine. The sudden change in temperature may crack the cylinder head or block.
If the entire system has been drained, redo the previous steps while maintaining the two heater line shutoff valves in the "Open" position. With engine running, activate the driver's and central heating systems to permit coolant circulation.
Complete the procedure by bleeding the heater cores as explained in Section 22, under “9.4
Bleeding Heating System”.
7. FLUSHING
If the cooling system is contaminated, flush the cooling system as follows:
1. Drain the coolant from the engine.
2. Refill with clean water.
05-10
Caution: If the engine is hot, fill slowly to prevent rapid cooling and distortion of the engine castings.
3. To thoroughly circulate the water, start and run the engine for 15 minutes after the thermostats have opened.
4. Fully drain system.
5. Refill with clean water and operate for 15 minutes after the thermostats have opened.
6. Stop engine and allow to cool.
7. Fully drain system.
Vehicles without coolant filters:
Fill with a 50/50-antifreeze/water solution and add required inhibitors.
Vehicles with coolant filters:
Replace the coolant filter with a precharge element filter; in this case do not mix inhibitors with antifreeze/water solution.
Dispose of spent fluids in an environmentally responsible manner according to regulations in effect in your area.
7.1 COOLING SYSTEM DESCALERS
If the engine overheats and the fan belt tension, coolant level and thermostat operation have been found to be satisfactory, it may be necessary to de-scale and flush the entire cooling system.
Remove scale formation by using a reputable and safe de-scaling solvent. Immediately after using the de-scaling solvent, neutralize with a neutralizing agent. It is important that product directions be thoroughly read and followed.
After using the solvent and neutralizer, fully drain the system, then reverse flush the engine and radiator (see "Reverse Flushing" in this section) before filling the system with coolant solution.
7.2 REVERSE FLUSHING
After the engine and radiator have been thoroughly de-scaled, they should be reverseflushed. The water pump should be removed and the radiator and engine reverse-flushed separately to prevent dirt and scale deposits from clogging the radiator tubes or being forced through the pump. Reverse flushing is
accomplished by hot water, under pressure, being forced through the cooling system in a direction opposite to the normal flow of coolant, loosening and forcing deposits out.
The radiator is reverse flushed as follows:
1. Remove the radiator inlet and outlet hoses and replace existing radiator cap with a new one.
2. Attach a hose to the top of the radiator to lead water away from the engine.
3. Attach a hose at the bottom of the radiator and insert a flushing gun in the hose.
4. Connect the water hose of the gun to the water outlet and the air hose to the compressed air outlet.
5. Turn on the water and when the radiator is full, turn on the air in short blasts, allowing the radiator to fill between blasts.
Note: Apply air gradually. Do not exert more than 138 kPa (20 psi) air pressure. Too great a pressure may rupture a radiator tube.
6. Continue flushing until only clean water is expelled from the radiator.
The cylinder block and cylinder head water passages are reverse flushed as follows:
1. Remove the thermostats and the water pump.
2. Attach a hose to the water inlet of oil cooler housing to drain water away from engine.
3. Attach a hose to the water outlet at the top of the cylinder head (thermostat housing) and insert the flushing gun in the hose.
4. Turn on the water until the jackets are filled, and then turn on the air in short blasts. Allow jackets to fill with water between air blasts.
5. Continue flushing until the water from the engine runs clean.
If scale deposits in the radiator cannot be removed by chemical cleaners or reverse flushing as outlined above, it may be necessary to remove the upper tank and rod out the individual radiator tubes with flat steel rods.
Circulate the water through the radiator core from the bottom to the top during this operation.
Section 05: COOLING SYSTEM
8. SPIN-ON COOLANT FILTER
The optional engine cooling system filter is used to filter out impurities such as scale or sand from the coolant and it also eliminates the process of adding inhibitors to the antifreeze/water solution.
The filter is mounted to the engine cradle
(Fig. 10).
The precharge element filter lasts for 12,500 miles (20 000 km) or one year, whichever comes first. Replace the precharge element filter with a maintenance element filter, which lasts for
200,000 miles (320 000 km) or two years, whichever comes first. Each time the coolant is renewed, a precharge element filter must be installed before installing a maintenance element filter.
05-11
FIGURE 10: COOLANT FILTER 05072
Note: If a coolant filter is to be installed on an engine already in service, drain and flush the cooling system before installing the filter.
To replace a filter:
1. Close the two filter shutoff cocks on the filter mounting head and unscrew the old filter from mounting.
Warning: Failure to relieve cooling system pressure may result in personal injury.
2. Remove and discard the filter.
3. Clean the filter adapter with a clean, lint-free cloth.
4. Coat surface of gasket with oil, tighten 2/3 to
1 turn after gasket makes contact with head.
5. Open the two filter shutoff cocks.
Section 05: COOLING SYSTEM
6. Start engine and check for leaks.
Caution: Do not exceed recommended service intervals.
9. RADIATOR
The radiator is mounted on the L.H. side of engine compartment. It is designed to reduce the temperature of the coolant under all operating conditions. It is essential that the radiator core be kept clean and free from corrosion and scale at all times.
9.1 MAINTENANCE
Inspect the exterior of the radiator core every
25,000 miles (40 000 km) or once a year, whichever comes first. Clean with a quality grease solvent, such as a mineral spirits and dry with compressed air. Do not use fuel oil, kerosene, gasoline, or any caustic material. It may be necessary to clean the radiator more frequently if the vehicle is operated in extremely dusty or dirty areas. Refer to coolant system flushing and reverse flushing in this section for maintenance of radiator interior.
10. VARIABLE SPEED RADIATOR FAN
The radiator fan has two thermostatically controlled speeds. The ECM controls the speed by comparing data from engine temperature, coolant temperature and air inlet temperature to a set of calibration data. The fan drive clutch is electromagnetic; the ECM sends an electric current to regulate speed by activating one magnetic coil for the first speed and two magnetic coils for the second speed.
The settings are:
For Series 60 engines with motor serial numbers up to 06R0194000 inclusively
• 204°F (96°C) first speed
• 208°F (98°C) second speed
For Series 60 engines with motor serial numbers from 06R0194000
• 196°F (91°C) first speed
• 203°F (95°C) second speed
Note: In case of an electrical power failure: remove the bolt from the end of the shaft and screw it into the locking plate. This procedure will prevent engine from overheating by forcing fan rotation (Fig. 11).
FIGURE 11: MECHANICAL LOCKING DEVICE
05061
10.1 MAINTENANCE
1. Clean the fan and related parts with clean fuel oil and dry them with compressed air. Do not clean with steam or high-pressure jet.
2. Check the fan blades for cracks or other damage. Replace the fan if the blades are cracked or deformed.
3. Remove any rust or rough spots in the grooves of the fan pulley. If the grooves are damaged or severely worn, replace the pulley.
4. Do not add any fluids or lubricants to the fan driving mechanism.
5. Do not restrict fan rotation during engine operation for any reason.
6. Do not operate fan-driving mechanism with a damaged fan assembly. Replace a damaged fan as soon as the fault is noted.
7. Immediately investigate and correct any operator complaint involving driving mechanism or cooling system performance.
8. When questions arise, obtain answers before proceeding. Assistance is available through the authorized Field Sales distributor serving your area.
05-12
10.2 INSPECTION
Warning: Set the starter selector switch in engine compartment to the "Off" position to prevent accidental starting of the engine.
• Check security of fasteners securing fan blade assembly to fan driving mechanism.
• Check coupling installation between fan blade assembly and gearbox.
• Visually inspect fan driving mechanism, fan blade assembly, shroud, radiator, and surrounding area for evidence of contact between rotating and non-rotating parts.
• Check fan transfer belt for fraying, cracking, and proper tension.
• Turn fan through at least 360° of rotation. It should turn smoothly with no resistance.
10.3 THERMOSTAT OPERATION
Coolant temperature is controlled by two blocking-type thermostats located in a housing attached to the cylinder head, on the turbo side of the engine (Fig. 12).
Section 05: COOLING SYSTEM the bypass system, and allowing a portion of the coolant to recirculate through the radiator. When the coolant temperature reaches approximately
205-207°F (96-97°C) thermostat valves are fully open, the bypass system is blocked off and the coolant is directed through the radiator.
11. FAN GEARBOX
The radiator fan is belt driven from the engine crankshaft pulley through a standard gearbox, which is designed with two output shafts.
FIGURE 12: THERMOSTAT AND RELATED PARTS
05034
At coolant temperature below approximately
190°F (88°C), the thermostat valves remain closed and block the flow of coolant from the engine to the radiator. During this period, all of the coolant in the system is recirculated through the engine and directed back to the suction side of the water pump via a bypass tube. As the coolant temperature rises above 190°F (88°C) the thermostat valves start to open, restricting
05-13
FIGURE 13: FAN GEARBOX
05062
11.1 MAINTENANCE
Change the gearbox oil at 3,000 miles (4,800 km) and subsequently every 50,000 miles
(80,000-km) or once a year, whichever comes first.
11.2 OIL CHANGE
1. Stop engine and make sure that all engine safety precautions have been observed.
2. Remove the drain plug located underneath the gearbox case.
3. Drain gearbox.
4. Replace drain plug.
5. Remove the dipstick located on top of gearbox and wipe with a clean rag (Fig. 13).
6. Adjust level to ″ Full ″ mark using Mobil SHC
630 (Prévost #180217) synthetic oil.
7. Insert dipstick in gearbox case, then remove again to check mark.
Section 05: COOLING SYSTEM
8. Reinsert the dipstick.
Caution : Vehicles up to V.I.N.
#2PCH3341XX1012847 use Mobil SHC 634
(Prévost #180185). Do not mix these two types of oil. to provide a 2-3/8" to 2-½" (60 to 64 mm) bracket extension under normal pressure of 50 psi - 345 kPa. Refer to figure 16 for more information.
12. RADIATOR FAN BELT REPLACEMENT
Locate the belt tensioner pressure-releasing
14), then turn handle counterclockwise in order to release pressure in belt tensioner air bellows, thus releasing tension on belts.
FIGURE 14: PRESSURE RELEASING VALVE
01063
Remove existing belts (3 ″ V ″ belts & 1 Poly) from fan assembly and replace with new ones.
Turn the pressure-releasing valve clockwise to its initial position to apply tension on the new belts.
Note: For proper operation of the belts, adjust the air bellows tensioner pressure regulating valve (located next to control valve) to 50 psi
(345 kPa) for vehicles with Series 60 engines.
12.1 BELT TENSION ADJUSTMENT
The regulator is located in the engine compartment behind the belt tension pressure releasing valve panel. Turn the screw located under the regulator assembly to change the tension pressure. Check proper pressure using the pressure check valve (Fig. 15).
Use Belt Tension Gauge #68-2404 to measure tension of engine belts. For proper operation of air tensioners, adjust upper tensioning bracket
05-14
FIGURE 15: REGULATOR VALVE
FIGURE 16: BELT TENSIONER
12151
01059
13. FAN DRIVE ALIGNMENT
1. Install both attachment assembly plates (P/N
051779) (48, Fig. 17) through lower plating and secure with four spring nuts (P/N 500666), (70,
Fig. 17). Then install one spacer (P/N 050705),
(49, Fig. 17) on each spring nut at both anchoring locations (Fig. 17).
Section 05: COOLING SYSTEM
Note: Use a straight edge to measure engine pulley's vertical angle (Fig. 19).
FIGURE 17: ANGLE SUPPORT 05014
2. Center seat assembly in the fan shroud using the horizontal displacement of the fan driving mechanism support. Center with the slots in the floor at anchoring angle support (on some vehicles only). Vertical displacement of the fan clutch is made possible by slots at the base of the fan clutch (on some vehicles only) or by shimming with additional spacers at anchoring locations. Temporarily secure assembly with two nuts (P/N 500709), (74,
Fig. 17) at both anchoring locations.
Caution: Tilt fan and check for clearance.
3. Using a straight edge, align the 3"V"pulley on gearbox central shaft pulley with engine pulley, while taking pulleys outer edge thickness under consideration i.e. 3"V"pulley's outer edge is thicker than that of engine pulley's (Fig. 18).
FIGURE 18: PULLEY ALIGNMENT 05064
4. Using a universal protractor, check 3"V" pulley's vertical angle with that of engine pulleys. If angles do not correspond, raise seat assembly by shimming with additional spacers (#49 - P/N 050705).
05-15
FIGURE 19: PULLEY VERTICAL ANGLE
05063
5. Check alignments again (steps 3, 4 & 5) then replace temporary anchoring nuts
(P/N 500709) (74, Fig. 17) with four nuts
(P/N 500714) (47, Fig. 17) and tighten using a wrench.
6. Align multi "V" pulley with fan pulley. Adjust the depth of the pulley on the gearbox shaft.
7. Set belt tensioner pressure regulating valve to 50 PSI - 345 kPa.
.
Caution: In order for tensioning system to work properly, the distance between the inside faces of belt tensioning brackets should be between 2-
3/8" (60 mm) and 2 ½" (64 mm). Otherwise, release tension on system and readjust distance using bolts securing upper tensioning bracket
(Fig. 16).
Section 05: COOLING SYSTEM
14. SPECIFICATIONS
Cooling System Capacity (Approximation)
Includes heating system........................................................................................................ 24 US gal (91 liters)
Thermostat
Number used........................................................................................................................................................ 2
Start to open .........................................................................................................................186-193°F (86-89°C)
Fully open ......................................................................................................................................... 207°F (97°C)
Radiator
Make ...............................................................................................................................................................Long
Location .......................................................................................................................................... Rear L.H. side
XL2 Buses
Supplier number.......... ......................................................................................................................... 7601-8361
Prevost number........... ...............................................................................................................................550742
XL2 MTH
Supplier number.... ............................................................................................................................... 7601-8357
Prevost number........... ...............................................................................................................................550748
Surge Tank Filler Cap
Make .............................................................................................................................................................. Stant
Model ................................................................................................................................................................. R3
Prevost number ..........................................................................................................................................052355
Pressure Cap
Make .............................................................................................................................................................. Stant
Pressure setting........................................................................................................................ 14 psi (96.53 kPa)
Supplier number .............................................................................................................................................. R12
Prevost number ..........................................................................................................................................550606
Fan Clutch
Make ............................................................................................................................................................. Linnig
Type ...........................................................................................................................................................3 speed
XL2 Buses
Supplier number ..................................................................................................................................LA1.2.024Y
Prevost number ..........................................................................................................................................550803
XL2 MTH
Supplier number.... ................................................................................................................................ LA1.2.073
Prevost number........... ...............................................................................................................................550802
Note: The fan clutch is controlled by DDEC (not by thermoswitch).
Fan Gearbox
Make ..........................................................................................................................................Superior Gearbox
Ratio...................................................................................................................................................................1:1
Supplier number .............................................................................................................................411ACF-097-6
Prevost number ..........................................................................................................................................550789
Lubricating Oil............................................................................................................................. MOBIL SHC 630
Prevost number (Oil) ..................................................................................................................................683666
05-16
Section 05: COOLING SYSTEM
Caution : Vehicles up to V.I.N. #2PCH3341XX1012847 use Mobil SHC 634 (Prévost #682268). Do not mix these two types of oil.
Fan Belt (gearbox-fan)
Make .............................................................................................................................................................Dayco
Type .......................................................................................................................................Multi-V, Poly rib, 51”
Qty ........................................................................................................................................................................1
Supplier number .......................................................................................................................................5100495
Prevost number ..........................................................................................................................................506663
Fan Belt (gearbox-motor)
Make ............................................................................................................................................................. Gates
Type ...............................................................................................................................................................V belt
Qty ........................................................................................................................................................................3
Series 60 Engines:
Supplier number ............................................................................................................................................AX74
Prevost number ..........................................................................................................................................506690
Corrosion Inhibitor and Coolant Stabilizer
Supplier number.......Detroit Diesel........................................................................................................23507857
Supplier number.......Nalco.................................................................................................................. DD3000-15
Coolant Filter
Number used........................................................................................................................................................ 1
Make ..............................................................................................................................................................Nalco
Type ........................................................................................................................................................... Spin-on
MAINTENANCE ELEMENT FILTER
Supplier number. ....Detroit Diesel........................................................................................................23507545
Supplier number......Nalco...................................................................................................................... DDF3000
Prevost number ..........................................................................................................................................550630
PRECHARGE ELEMENT FILTER
Supplier number. ....Detroit Diesel........................................................................................................23507189
Supplier number......Nalco.......................................................................................................................... DDF60
Prevost number ..........................................................................................................................................550629
05-17
SECTION 06: ELECTRICAL
CONTENTS
1.1 WIRING DIAGRAMS .................................................................................................................06-6
Diagram Keys..........................................................................................................06-6
Wiring Diagrams.......................................................................................................06-6
1.1.3 Testing Circuits...................................................................................................................06-6
1.2 WIRE SIZES AND COLORS......................................................................................................06-6
1.3 SPARE WIRES ..........................................................................................................................06-7
1.4 CLEANING CONNECTORS......................................................................................................06-7
1.5 CIRCUIT BREAKERS................................................................................................................06-7
1.6 RELAYS.....................................................................................................................................06-7
2. XL2 COACHES ELECTRICAL COMPARTMENTS AND JUNCTION BOXES ............................06-10
2.1 MAINTENANCE.......................................................................................................................06-11
2.2 BOOSTER BLOCK ..................................................................................................................06-11
2.3 BATTERY SAFETY SWITCH ..................................................................................................06-11
2.4 BATTERIES.............................................................................................................................06-11
2.5 CIRCUIT BREAKERS..............................................................................................................06-12
2.6 FRONT SERVICE COMPARTMENT ......................................................................................06-12
2.6.1 L.H. Side of Front Baggage Compartment (Vehicle Equipped With Video System) .......06-13
2.7 ENGINE COMPARTMENT (REAR JUNCTION BOX).............................................................06-13
3. XL2 MOTORHOMES ELECTRICAL COMPARTMENTS AND JUNCTION BOXES ...................06-14
3.1 MAINTENANCE.......................................................................................................................06-15
3.2 BOOSTER BLOCK ..................................................................................................................06-15
3.3 BATTERY SAFETY SWITCH ..................................................................................................06-15
3.4 BATTERIES.............................................................................................................................06-16
3.5 CIRCUIT BREAKERS..............................................................................................................06-16
3.6 FRONT SERVICE COMPARTMENT ......................................................................................06-17
3.7 ENGINE COMPARTMENT (REAR JUNCTION BOX).............................................................06-18
4. BATTERIES....................................................................................................................................06-18
4.1 BATTERY REMOVAL AND INSTALLATION...........................................................................06-19
4.1.1 XL2-40 Coach ..................................................................................................................06-19
4.1.2 XL2-45 Coach ..................................................................................................................06-19
4.1.3 Xl2-40, XL2-45E and XL2 45 Bus Shells .........................................................................06-20
4.2 BATTERY RATING..................................................................................................................06-20
4.3 BATTERY TESTING................................................................................................................06-21
Inspection ..............................................................................................................06-21
4.3.2 Removing
4.3.3 Load
Surface Charge...............................................................................................06-21
Test..........................................................................................................................06-21
Battery Cables .....................................................................................................06-22
4.4 BATTERY CHARGING............................................................................................................06-23
Charging Guide....................................................................................................06-24
4.4.2 Emergency Jump Starting With Auxiliary (Booster) Battery ............................................06-24
4.5 CLEANING AND INSPECTION...............................................................................................06-25
4.6 COMMON CAUSES OF BATTERY FAILURE.........................................................................06-25
4.7 TROUBLESHOOTING ............................................................................................................06-25
5.1 TELLTALE LIGHT DEFINITIONS............................................................................................06-26
06-1
Section 06: ELECTRICAL
8. CHARGING SYSTEM TROUBLESHOOTING...............................................................................06-28
8.1 ALTERNATOR OR VOLTAGE REGULATOR.........................................................................06-28
8.2 ALTERNATOR DIAGNOSIS....................................................................................................06-29
8.2.1 Diode
8.2.2 Field
8.2.3 Stator
8.3 DIODE REPLACEMENT .........................................................................................................06-31
Replacement (in Support)......................................................................................06-32
8.3.2 Diode (in End Frame).................................................................................06-32
8.4 FIELD REMOVAL ....................................................................................................................06-32
8.5 FIELD INSTALLATION ............................................................................................................06-32
8.6 STATOR REPLACEMENT ......................................................................................................06-33
8.6.1 Removal ...........................................................................................................................06-33
Stator Terminal Leads......................................................................................06-33
8.6.3 Installation ........................................................................................................................06-33
8.7 DIODE END COVER INSTALLATION.....................................................................................06-33
8.8 ALTERNATOR REMOVAL (DELCO) ......................................................................................06-33 of Alternator ................................................................................................06-34
Cleaning and Inspection ..................................................................................06-34
8.8.3 Bearing or Rotor Replacement.........................................................................................06-35
8.8.4 Alternator Reassembly .....................................................................................................06-35
8.8.5 Output check ....................................................................................................................06-36
8.9 ALTERNATOR DRIVE BELT...................................................................................................06-36
8.9.1 Adjustment........................................................................................................................06-36
9.1 TROUBLESHOOTING PROCEDURES ..................................................................................06-37
9.1.1 Undercharged Battery ......................................................................................................06-38
9.1.2 Overcharged Battery ........................................................................................................06-38
9.2 REGULATOR CHECKS ..........................................................................................................06-38
9.3 ADJUSTING VOLTAGE ..........................................................................................................06-39
11. STARTER ...................................................................................................................................06-40
11.1 MAINTENANCE.......................................................................................................................06-40
11.2 TROUBLESHOOTING ............................................................................................................06-40
11.2.1 No-Load Test....................................................................................................................06-40
11.2.2 Lock-Torque Test .............................................................................................................06-41
11.3 DISASSEMBLY .......................................................................................................................06-41
11.3.1 Cleaning ...........................................................................................................................06-42
11.3.2 Armature Servicing...........................................................................................................06-42
Coil Checks .............................................................................................................06-42
Coil Removal ...........................................................................................................06-42
11.3.5 Reassembly......................................................................................................................06-43
11.4 PINION CLEARANCE .............................................................................................................06-43
11.5 STARTER SOLENOID ............................................................................................................06-43
11.5.1 Disassembly .....................................................................................................................06-43
Maintenance......................................................................................................06-43
11.5.3 Solenoid Tests..................................................................................................................06-43
11.5.4 Recommendations ...........................................................................................................06-44
12.1 MAINTENANCE.......................................................................................................................06-44
06-2
Section 06: ELECTRICAL
13.1 HEADLIGHTS..........................................................................................................................06-45
13.1.1 Headlight
13.1.2 Maintenance.....................................................................................................................06-45
13.1.3 Headlight Adjustment .......................................................................................................06-45
Unit Replacement ............................................................................................06-47
13.1.5 Headlight Bulb Removal and Replacement .....................................................................06-47
13.2 FRONT TURN SIGNAL ...........................................................................................................06-48
13.2.1 Front Turn Signal Light Replacement ..............................................................................06-48
13.2.2 Front Turn Signal Light Bulb Removal and Replacement................................................06-48
13.3 STOP, TAIL, DIRECTIONAL, BACK-UP, AND HAZARD WARNING LIGHTS ........................06-48
Removal
13.4 LICENSE PLATE LIGHT..........................................................................................................06-48
13.5 CLEARANCE, IDENTIFICATION AND MARKER LIGHTS .....................................................06-48
13.5.1 Marker Light Removal and Replacement.........................................................................06-49
13.5.2 Clearance and Identification Light Removal and Replacement .......................................06-49
13.6 DOCKING AND CORNERING LIGHTS...................................................................................06-49
13.6.1 Lamp
13.7 FOG LIGHTS ...........................................................................................................................06-49
13.7.1 Bulb
14.1 CONTROL PANEL LIGHTING ................................................................................................06-50
14.1.1 Switch Lighting .................................................................................................................06-50
Light Replacement...............................................................................................06-50
14.1.3 Gauge Light Bulb Replacement .......................................................................................06-50
14.2 STEPWELL LIGHTS AND LAVATORY NIGHT-LIGHT ...........................................................06-50
Removal
14.3 DRIVER’S AREA LIGHTS .......................................................................................................06-51
Removal
14.4 PASSENGER SECTION LIGHTING .......................................................................................06-51
Tube Replacement .......................................................................................06-51
14.4.2 Removal and Replacement of In-Station Fluorescent Tubes ..........................................06-52
14.4.3 Removal and Replacement of Reading Lamp Bulb .........................................................06-52
14.5 ENGINE COMPARTMENT LIGHTING....................................................................................06-52
14.6 LAVATORY LIGHT ..................................................................................................................06-52
16. SPECIFICATIONS ......................................................................................................................06-54
06-3
Section 06: ELECTRICAL
ILLUSTRATIONS
FIGURE 1: WIRE IDENTIFICATION ........................................................................................................06-7
FIGURE 2: TYPES OF RELAYS ..............................................................................................................06-9
FIGURE 3: ELECTRICAL COMPARTMENT (XL2-40 COACH).............................................................06-10
FIGURE 4: ELECTRICAL COMPARTMENT (XL2-45 COACH).............................................................06-10
FIGURE 5: MAIN POWER COMPARTMENT (XL2-45) .........................................................................06-11
FIGURE 6: BATTERY COMPARTMENT (XL2-40) ................................................................................06-11
FIGURE 7: LOCATION OF A/C JUNCTION BOX IN EVAPORATOR COMPARTMENT ......................06-12
FIGURE 8: A/C JUNCTION BOX ...........................................................................................................06-12
FIGURE 9: TOP SECTION OF FRONT SERVICE COMPARTMENT....................................................06-12
FIGURE 10: BOTTOM SECTION OF FRONT SERVICE COMPARTMENT .........................................06-13
FIGURE 11: DDR CONNECTOR LOCATION IN DRIVER'S AREA.......................................................06-13
FIGURE 12: L.H.
SIDE OF REAR BAGGAGE COMPARTMENT'S CEILING........................................06-13
FIGURE 13: REAR JUNCTION BOX SWITCHES .................................................................................06-13
FIGURE 14: REAR JUNCTION BOX .....................................................................................................06-13
FIGURE 15: ELECTRICAL COMPARTMENTS (XL2-40 BUS SHELLS) ...............................................06-14
FIGURE 16: ELECTRICAL COMPARTMENTS (XL2-45E BUS SHELLS).............................................06-14
FIGURE 17: ELECTRICAL COMPARTMENTS (XL2-45 BUS SHELLS) ...............................................06-15
FIGURE 18: BREAKER PANEL .............................................................................................................06-15
FIGURE 19: ENGINE COMPARTMENT R.H.
SIDE...............................................................................06-16
FIGURE 20: LOCATION OF A/C JUNCTION BOX IN EVAPORATOR COMPARTMENT ....................06-16
FIGURE 21: A/C JUNCTION BOX .........................................................................................................06-17
FIGURE 22: TOP SECTION OF FRONT SERVICE COMPARTMENT..................................................06-17
FIGURE 23: BOTTOM SECTION OF FRONT SERVICE COMPARTMENT .........................................06-17
FIGURE 24: DDR CONNECTOR LOCATION IN DRIVER'S AREA.......................................................06-17
FIGURE 25: REAR JUNCTION BOX SWITCHES .................................................................................06-18
FIGURE 26: REAR JUNCTION BOX .....................................................................................................06-18
FIGURE 27: BATTERIES (TYPICAL).....................................................................................................06-18
FIGURE 28: TEST INDICATOR .............................................................................................................06-21
FIGURE 29: LOAD TEST .......................................................................................................................06-22
FIGURE 30: ALLIGATOR CLAMPS AND BATTERY .............................................................................06-23
FIGURE 31: OIL CIRCULATION THROUGH ALTERNATOR ...............................................................06-27
FIGURE 32: ALTERNATOR WIRING DIAGRAM (DELCO)...................................................................06-28
FIGURE 33: CONNECTIONS FOR CHECKING ALTERNATOR OUTPUT...........................................06-29
FIGURE 34: VIEW OF RECTIFIER END FRAME WITH COVER REMOVED .......................................06-30
FIGURE 35: DIODE TESTING ...............................................................................................................06-30
FIGURE 36: DIODE TESTING ...............................................................................................................06-31
FIGURE 37: STATOR WINDING TEST .................................................................................................06-31
FIGURE 38: ALTERNATOR (HOSES AND WIRES)..............................................................................06-34
FIGURE 39: ALTERNATOR RETAINING BOLTS AND WASHERS......................................................06-34
FIGURE 40: ALTERNATOR DRIVE BELT.............................................................................................06-36
FIGURE 41: VOLTAGE REGULATOR...................................................................................................06-36
FIGURE 42: TYPICAL WIRING DIAGRAM OF A NEGATIVE GROUND SYSTEM ...............................06-37
FIGURE 43: REGULATOR VOLTAGE SETTING ..................................................................................06-37
FIGURE 44: ADJUSTING REGULATOR VOLTAGE SETTING.............................................................06-38
FIGURE 45: REGULATOR VOLTAGE TEST (UNDERCHARGED BATTERY).....................................06-38
FIGURE 46: CHECKING TRANSISTOR TR1 ........................................................................................06-39
FIGURE 47: CHECKING TRANSISTOR TR2 ........................................................................................06-39
FIGURE 48: TYPICAL STARTER CROSS SECTION............................................................................06-40
FIGURE 49: STARTING MOTOR NO-LOAD TEST ...............................................................................06-41
FIGURE 50: PINION CLEARANCE........................................................................................................06-43
FIGURE 51: ELECTRIC HEATER PLUG LOCATION............................................................................06-44
FIGURE 52: HEADLIGHT ASSEMBLY ..................................................................................................06-45
FIGURE 53: HEADLIGHT ALIGNMENT ................................................................................................06-45
FIGURE 54: HEADLIGHT ALIGNMENT ................................................................................................06-46
06-4
Section 06: ELECTRICAL
FIGURE 55: HEADLIGHT ALIGNER......................................................................................................06-46
FIGURE 56: HEADLIGHT ALIGNMENT ................................................................................................06-46
FIGURE 57: HEADLIGHT ALIGNMENT ................................................................................................06-46
FIGURE 58: ALIGNMENT SCREWS .....................................................................................................06-47
FIGURE 59: TOP VIEW OF HEADLIGHT ASSEMBLY..........................................................................06-47
FIGURE 60: VARIOUS LIGHTS LOCATION .........................................................................................06-49
FIGURE 61: SWITCH.............................................................................................................................06-50
FIGURE 62: PARCEL RACK LIGHTING................................................................................................06-51
FIGURE 63: ENGINE COMPARTMENT LIGHT ....................................................................................06-52
06-5
Section 06: ELECTRICAL
DESCRIPTION
This vehicle uses a dual voltage system to obtain two different voltages (12 and 24 volts) for various electrical controls and accessories.
The main power source incorporates four maintenance-free “Delco” model 1150 batteries connected in parallel-series. All batteries are kept uniformly charged by means of a 100 amp battery equalizer (standard), giving a maximum possible output supply of 100 amps on the 12 volt system. Both the 12 and 24 volt systems are controlled through individual main battery relays.
One or two 24 volt self-rectified alternators are belt driven from the engine, and can be reached through the engine compartment door.
A master wiring diagram of the electric circuits, covering standard and optional accessories and systems, is located in the technical publications box. Usually, a separate wiring diagram page is provided for each major function or system. In some cases, more than one circuit may appear on one wiring diagram page; when this occurs, each circuit covered in this page is listed in the wiring diagram index. Moreover, a circuit may appear on several pages; in such case, the number(s) at the extremity of the diagram title will indicate the sheet reference number. Refer to the "Wiring Diagram Index " to ensure that the correct diagram is being used to trace the circuit in question.
1.1.1 Wiring Diagram Keys
Various symbols are used on the wiring diagrams to depict different types of electrical components. It is essential to become familiar with these symbols in order to understand the diagrams. The major symbols shown on the diagrams are identified under "Wiring Diagram keys" (page K of wiring diagrams).
1.1.2 Using Wiring Diagrams
Two methods are used to "work" with electric wiring diagrams.
Situation: You have identified the defective part
(breaker, diode, relay, etc.), and you wish to locate its corresponding circuit.
Problem: Circuit breaker #56 is released (open circuit) and you don't know which circuit is affected. a) Refer to wiring diagram index, and look for
"Circuit breaker code" , pages F . b) At item CB #56, in the first column, you will find the page on which to find the
06-6 corresponding diagram, in the second column the breaker ampere rating, and in the third column, the Prévost number. The other columns give you the location and the function of the breaker.
c) Refer to page 4, keeping in mind the function of the breaker, i.e. emergency exit lights. d) When you have located “emergency exit lights”, follow the wiring until you come across CB #56 and its circuit.
Situation: You have a problem with a specific system and you want to find the corresponding diagram.
Problem: The last three (3) speakers on the
R.H. side of vehicle are inoperative and you must trace the electric circuit. a) Refer to wiring diagram index and look for
“Sound system”.
b) You will find on page 26 the components as well as the electric wiring, thus providing you with a complete understanding of this circuit.
A careful study of the wiring diagrams should be made to determine the source and flow of current through each circuit. When a circuit is thoroughly understood, a point-to-point check can be made with the aid of the applicable wiring diagrams. Any circuit can be tested for continuity or short circuits with a multimeter or a suitable voltmeter.
All electrical connections must always be kept clean and adequately tight. Loose or corroded connections can result in discharged batteries, difficult starting, dim lights and improper functioning of other electric circuits. Inspect all wiring connections at regular intervals. Make sure knurled nuts on all amphenol-type plugs are securely tightened. Knurled nuts on the plastic amphenol-type connectors will click into a detent when properly tightened. Line connectors, who have the side locking tabs, must have the locks latched in place to ensure a proper electrical connection.
1.2 WIRE SIZES AND COLORS
Each wire in the electrical system has a specific size as designated on the wiring diagram. When replacing a wire, the correct size must be used.
Never replace a wire with one of a smaller size.
The vehicle electrical system is provided with different voltages. The insulation on each wire is distinctly colored in order to determine visually
the wiring voltage and to assist in making connectors. The wires are color coded as follows:
Red 24 volt system
Yellow
Blue
White
12 volt system
Black grounded
110 V ac system (live)
110 V ac system (neutral)
Green 110 V ac system (ground)
(+)
Brown speakers
Note: Wires are identified at each 2-4 inch (5-
10 cm) intervals by a printed number.
Each wire on a diagram is patterned to assist in tracing and testing circuits. The wire number identifies the voltage rating, the wire identification number and the basic wire gauge as illustrated in figure 1.
FIGURE 1: WIRE IDENTIFICATION
06048
When the vehicle leaves the factory, and even in the case of a fully-equipped vehicle, an important number of unconnected spare wires are routed between the junction boxes.
Consequently , for any connection of an additional accessory, refer to page D "Spare wires" in master wiring diagram to determine the number, the gauge and location of these wires.
Note: Spare wires are identified by a wire identification number and by the letters “SP”, to designate “spare”.
Warning:
When the pins and sockets of connectors become dirty, clean them with a good quality solvent containing HFC 134A refrigerant as its active ingredient. HFC 134A has two qualities that recommend it. First, it does not conduct electricity and therefore, will not cause shorting between connector pins and sockets. Second, it evaporates quickly, eliminating the possibility of condensation within the connectors.
Always shake out or gently blow out any excess
HFC 134A before assembling a connector to its mating connector or hardware. HFC 134A trapped in the connector can affect the connector seal.
06-7
Section 06: ELECTRICAL
HFC 134A is toxic. HFC 134A bases compounds should always be used in a wellventilated area, never in a confined space. Use outdoor whenever possible.
Most electric circuits are protected by circuit breakers of the “Manual Reset” type. The main circuit breakers, as well as those protecting the
A/C system, are located in the engine compartment, on R.H. side of the vehicle, in the main power compartment or in the rear baggage compartment depending on type of vehicle. The remaining are located in the evaporator compartment, inside the A/C junction box.
CIRCUIT BREAKERS
CB1 A/C Full Air
CB2 Hot Wire
24 volts 200 amps
12 volts 40 amps
CB3 Rear Junction Box 12 volts 70 amps
CB4 Front Junction Box 12 volts 90 amps
CB5 Hot Wire 24 volts 30 amps
CB6 Rear Junction Box 24 volts 90 amps
CB7 Front Junction Box 24 volts 90 amps
CB8
Condenser Fan
Motor L.H.
24 volts 40 amps
CB9
CB1
1
Motor
Condenser Fan
Motor R.H.
24 volts 40 amps
The smaller circuit breakers are accessible in the front service compartment and rear junction box. This type of circuit breaker deenergizes the circuit without disconnecting any wire. Simply press down the red tab on breaker to open the circuit, repair defective circuit, and afterwards depress black button in center of breaker to close the circuit.
1.6 RELAYS
Relays are used to automatically energize or deenergize a circuit from a remote location. The relay draws a very low current to energize its coil. Once the coil is energized, it develops a magnetic field that pulls a switch arm closed or open, to either energize or deenergize a given component. As the control current required for the coil is very low, the relay allows a remote station to control a high energy circuit without running great lengths of costly high capacity cable, and also eliminates the need for high amperage switches and heavy connectors.
Many systems on this vehicle are provided with control relays, which are all, located in or on the junction boxes, figure 2.
Section 06: ELECTRICAL
Note: Each relay is identified with “12V” or
“24V” printed on its casing in order to identify the coil operating voltage.
Caution: The magnetic relays for the starting motor, evaporator and both condenser motors and condenser speed controls should have the
5/16” stud nuts torqued to 50 + 5 in•lbf (5,5 + 0,5
N•m).
06-8
Section 06: ELECTRICAL
FIGURE 2: TYPES OF RELAYS
06-9
06050
Section 06: ELECTRICAL
2. XL2 COACHES ELECTRICAL COMPARTMENTS AND JUNCTION BOXES
FIGURE 3: ELECTRICAL COMPARTMENT (XL2-40 COACH)
06328
FIGURE 4: ELECTRICAL COMPARTMENT (XL2-45 COACH)
06329
06-10
2.1 MAINTENANCE
A Cortec VCI-238 corrosion inhibitor has been sprayed in all electrical compartments to protect components from corrosion. The life expectancy of this product is five years, so it is recommended to reapply it every five years. It is also recommended to spray it on new components when added or replaced.
Warning: Use VIC-238 in a well ventilated area. Do not smoke. Avoid prolonged contact with skin and breathing of spray mist. Harmful or fatal if swallowed. Do not induce vomiting. Call physician immediately.
On XL2-40 coaches, booster block is located in the engine compartment on the R.H. side and is accessible through engine R.H. side door. On
XL2-45 coaches, booster block is located in the main power compartment (Fig. 5).
Section 06: ELECTRICAL compartment (XL2-40), or in the main power compartment (XL2-45).
Caution: During repair or maintenance periods, set battery safety switch to the "OFF" position in order to avoid personal injury. This ensures that power is cut off even if master key switch is set to the “ON” position by mistake.
w
hen master key switch is set to the “OFF” position, electrical supply from the batteries is automatically cut off.
Note: When battery safety switch or master key switch is set to the "OFF" position, the electrical supply from the batteries is cut off, with the exception of the Fire Detection System, the
Engine & Transmission Electronic Controls, the
Auxiliary Heating System, the Battery Equalizers and the Digital Clock.
2.4 BATTERIES
To gain access to the battery compartment, open the R.H. side rear baggage compartment.
Batteries are accessible by means of an access door which is located on the back wall of the rear baggage compartment (XL2-40). To open battery access door, simply take out handle from it's cavity, turn ¼ counterclockwise and pull on the handle. The batteries are located in the main power compartment on the XL2-45 coach.
FIGURE 5: MAIN POWER COMPARTMENT (XL2-45)
06316
2.3 BATTERY SAFETY SWITCH
This switch disconnects both the 12 and 24 volts. This toggle switch is located in the battery
FIGURE 6: BATTERY COMPARTMENT (XL2-40)
06325
06-11
Section 06: ELECTRICAL
Electric Circuit Protection
Two type of cutoff mechanisms are installed to protect the vehicle's electrical system; fuses and manually-resettable circuit breakers. If an electrical device is inoperative, check the corresponding cutoff mechanism.
Caution: Never replace a fuse with a higher rated one because it will cause severe damage to the electric system.
Most of the manually-resettable circuit breakers are located in the: A/C junction box, rear junction box, front service compartment, rear baggage compartment and in the main power compartment. An identification decal is affixed on the inside face of each door.
XL2-40 and XL2-45 coaches are equipped with eight (8) main breakers; they are installed just below R.H. side rear baggage compartment's ceiling or in the main power compartment and in the A/C junction box in the evaporator compartment, they can be identified as follows
(Fig. 5, 6, 7and 8):
1. A/C full air (CB1) 200 amps-24 volts;
2. Front junction box (CB7) 90 amps-24 volts;
3. Rear junction box (CB6) 90 amps-24 volts;
4. Direct (CB4) 90 amps-12 volts;
5. Rear junction box (CB3) 70 amps-12 volts;
6. Condenser fan motor L.H. (CB8) 40 A-24 volts;
7. Evaporator fan motor (CB9) 120 amps-24 volts;
8. Condenser fan motor R.H. (CB11) 40 A-24 volts.
FIGURE 8: A/C JUNCTION BOX
06317
2.6 FRONT SERVICE COMPARTMENT
The front service compartment is located on
L.H. side of vehicle, under the driver's window. It contains the following components (Fig. 9 and
10):
• relays;
• breakers;
• alternator
• diodes;
• ABS blinker switch;
• electronic control unit for ABS.
FIGURE 7: LOCATION OF A/C JUNCTION BOX IN
EVAPORATOR COMPARTMENT
06414
FIGURE 9: TOP SECTION OF FRONT SERVICE
COMPARTMENT
06319
06-12
Section 06: ELECTRICAL
Battery Equalizers
On XL2-40 coach, two (2) battery equalizers
("VANNER"-50 amps-12 & 24 volts) are installed just below L.H. side rear baggage compartment's ceiling. The reset buttons are located on the end of equalizers facing the center of the coach (Fig. 12). On XL2-45 coach the battery equalizers are located in the main power compartment (Fig. 5).
FIGURE 10: BOTTOM SECTION OF FRONT SERVICE
COMPARTMENT
06394
DDR connector
To enhance troubleshooting and to allow interrogation of the ECU for valuable service information, a DDR (diagnostic data reader) can be used. To use it, plug the appropriate connector (not furnished by the manufacturer) in the terminal located in the rear junction box or the connector located on L.H. console (refer to fig. 11 and 14). You can also use your pushbutton shifter to perform certain maintenance operations (see Section 01, Engine, under paragraph "4. DDEC IV Diagnostic codes").
FIGURE 12: L.H. SIDE OF REAR BAGGAGE
COMPARTMENT'S CEILING 06326
2.7 ENGINE COMPARTMENT (REAR
JUNCTION BOX)
The rear junction box is located in the engine rear compartment.
Switches are located on R.H. side of rear junction box (Fig.13):
• engine compartment light switch;
• starter selector switch;
• rear start (push button switch).
FIGURE 11: DDR CONNECTOR LOCATION IN DRIVER'S
AREA 18375
2.6.1 L.H. SIDE OF FRONT BAGGAGE
COMPARTMENT (Vehicle Equipped With Video
System)
This compartment may contain the following components (Fig.12):
• protective screen (with video system);
• video inverter (with video system);
• electronic system monitor.
FIGURE 13: REAR JUNCTION BOX SWITCHES
01017
The rear junction box contains the following components (Fig. 14):
• relays;
• breakers;
• diodes;
• time delay relay;
• DDR
FIGURE 14: REAR JUNCTION BOX
06-13
06318
Section 06: ELECTRICAL
3. XL2 MOTORHOMES ELECTRICAL COMPARTMENTS AND JUNCTION BOXES
FIGURE 15: ELECTRICAL COMPARTMENTS (XL2-40 BUS SHELLS) 06330
FIGURE 16: ELECTRICAL COMPARTMENTS (XL2-45E BUS SHELLS)
06-14
06324
Section 06: ELECTRICAL
FIGURE 17: ELECTRICAL COMPARTMENTS (XL2-45 BUS SHELLS)
3.1 MAINTENANCE
A Cortec VCI-238 corrosion inhibitor has been sprayed in all electrical compartments to protect components from corrosion. The life expectancy of this product is five years, so it is recommended to reapply it every five years. It is also recommended to spray it on new components when added or replaced.
Warning: Use VIC-238 in a well ventilated area. Do not smoke. Avoid prolonged contact with skin and breathing of spray mist. Harmful or fatal if swallowed. Do not induce vomiting. Call physician immediately.
On all XL2 MTH, booster block is located on the breaker panel in the engine compartment on the
R.H. side and is accessible through engine R.H. side door (Fig. 18).
3.3 BATTERY SAFETY SWITCH
This switch disconnects both the 12 and 24 volts. This toggle switch is located on the breaker panel in the engine compartment on the
R.H. side and is accessible through engine R.H. side door (Fig. 18).
FIGURE 18: BREAKER PANEL
06-15
06323
06382
Section 06: ELECTRICAL
Caution: During repair or maintenance periods, set battery safety switch to the "OFF" position in order to avoid personal injury. This ensures that power is cut off even if master key switch is set to the “ON” position by mistake.
w
hen master key switch is set to the “OFF” position, electrical supply from the batteries is automatically cut off.
Note: When battery safety switch or master key switch is set to the "OFF" position, the electrical supply from the batteries is cut off, with the exception of the Fire Detection System, the
Engine & Transmission Electronic Controls, the
Auxiliary Heating System, the Battery Equalizers and the Digital Clock.
3.4 BATTERIES
The batteries are located in the engine compartment R.H. side (Fig. 19). The battery arrangement may differ between vehicle types due to available space.
Most of the manually-resettable circuit breakers are located in the: A/C junction box, rear junction box, front service compartment and in the engine compartment R.H. side. An identification decal is affixed on the inside face of each door.
MTH XL2-40, XL2-45E and XL2-45 may be equipped with ten (10) main breakers; six (6) of which are standard and four (4) are supplied only on vehicles with central A/C system. CB2 to
CB7 breakers are standard and CB1, CB8, CB9 and CB11 breakers are optional.
On all vehicles, breakers CB1 to CB7 are installed on breaker panel in engine compartment R.H. side (Fig. 18). They are accessible through engine R.H. side door and can be identified as follows:
1. A/C full air (CB1) 200 amps-24 volts;
2. Front junction box (CB7) 90 amps-24 volts;
3. Rear junction box (CB6) 90 amps-24 volts;
4. Direct (CB4) 90 amps-12 volts;
5. Rear junction box (CB3) 70 amps-12 volts;
6. Battery CB2) 40 amps-12 volts;
7. Battery (CB5) 30 amps-24 volts;
On all vehicles, optional breakers CB8, CB9 and
CB11 are installed in the A/C junction box in the evaporator compartment (Fig. 20 and 21), they can be identified as follows:
1. Condenser fan motor L.H. (CB8) 40 A-24 volts;
2. Evaporator fan motor (CB9) 120 amps-24 volts;
3. Condenser fan motor R.H. (CB11) 40 A-24 volts.
FIGURE 19: ENGINE COMPARTMENT R.H. SIDE
18354
Electric Circuit Protection
Two type of cutoff mechanisms are installed to protect the vehicle's electrical system; fuses and manually-resettable circuit breakers. If an electrical device is inoperative, check the corresponding cutoff mechanism.
Caution: Never replace a fuse with a higher rated one because it will cause severe damage to the electric system.
FIGURE 20: LOCATION OF A/C JUNCTION BOX IN
EVAPORATOR COMPARTMENT 06414
06-16
Section 06: ELECTRICAL
FIGURE 21: A/C JUNCTION BOX
06317
3.6 FRONT SERVICE COMPARTMENT
The front service compartment is located on
L.H. side of vehicle, under the driver's window. It contains the following components (Fig. 22 and
23):
• relays;
• breakers;
• alternator
• diodes;
• ABS blinker switch;
• electronic control unit for ABS.
FIGURE 23: BOTTOM SECTION OF FRONT SERVICE
COMPARTMENT
06394
DDR connector
To enhance troubleshooting and to allow interrogation of the ECU for valuable service information, a DDR (diagnostic data reader) can be used. To use it, plug the appropriate connector (not furnished by the manufacturer) in the terminal located in the rear junction box or the connector located on L.H. console (refer to fig. 24 and 26). You can also use your pushbutton shifter to perform certain maintenance operations (see Section 01, Engine, under paragraph "4. DDEC IV Diagnostic codes").
FIGURE 22: TOP SECTION OF FRONT SERVICE
COMPARTMENT
06319
FIGURE 24: DDR CONNECTOR LOCATION IN DRIVER'S
AREA 18375
06-17
Section 06: ELECTRICAL
3.7 ENGINE COMPARTMENT (REAR
JUNCTION BOX)
The rear junction box is located in the engine rear compartment.
Switches are located on R.H. side of rear junction box (Fig.25):
• engine compartment light switch;
• starter selector switch;
• rear start (push button switch).
FIGURE 25: REAR JUNCTION BOX SWITCHES
01017
The rear junction box contains the following components (Fig. 26):
• relays;
• breakers;
• diodes;
• time delay relay;
• DDR
FIGURE 26: REAR JUNCTION BOX
06318
4. BATTERIES
The vehicle is provided with four (4) maintenance-free 12 volt heavy-duty batteries connected in series-parallel (Fig. 27). The top-mounted negative and positive terminals are tightly sealed to prevent leaks. Water never needs to be added to this type of battery. There are no filler caps in the cover. The battery is sealed, except for small vent holes in the cover.
The vents must not be restricted as they allow small amounts of gases produced in the battery to escape. The special chemical composition inside the battery reduces gassing to a very small amount at normal charging voltages.
Besides reducing gassing, the special chemistry greatly reduces the possibility of overcharge damage.
FIGURE 27: BATTERIES (TYPICAL)
06343
The vents require keeping the battery in an upright position to prevent electrolyte leakage.
Tipping the battery beyond a 45
O
angle in any direction can allow a small amount of electrolyte to leak out of the vent holes.
Warning: DO NOT tip battery by more than
45 O when carrying or installing the battery.
Note: Evidence of electrolyte leakage does not necessarily mean the battery is defective.
With special cables properly attached to batteries, the metal surfaces that carry the current are completely sealed from the atmosphere. This prevents terminal oxidation and corrosion that may cause starting and charging problems. If new cables are required, sealed terminal cable replacements should be used to retain the reliability of the original maintenance-free connections.
Warning: All lead-acid batteries generate hydrogen gas, which is highly flammable. If ignited by a spark or flame, the gas may explode violently, causing spraying of acid, fragmentation of the battery, which may result in severe personal injuries. Wear safety glasses and do not smoke when working near batteries.
In case of contact with acid, flush immediately with water.
The battery has four (4) major functions:
1. Providing a source of current for starting the engine.
2. Stabilizing the voltage in the electrical system;
06-18
3. Supplying current for a limited time, when electrical demands of the equipment exceed the power output of the alternator;
4. Providing a limited source of power for connected accessories, when the engine is not running.
4.1 BATTERY
INSTALLATION
REMOVAL AND
The batteries are located in the rear baggage compartment (battery compartment).
Warning : To prevent possible electric shocks or sparking, the battery master switch should be in the "Off" position before disconnecting cables from the batteries (see paragraph "2.3 Battery master switch").
To remove lower defective batteries:
1. Remove the two (2) batteries retaining bracket nuts. Remove the batteries retaining bracket (Fig. 6).
2. Unscrew terminal nuts of each defective battery. Remove battery cables from the batteries.
3. Remove defective batteries.
To remove the upper battery:
1. Loosen the two (2) rod nuts and remove the battery securing bracket (Fig. 6).
2. Unscrew terminal. Remove battery cables from the battery.
3. Remove defective battery.
4. Installation is the reverse of removal.
Note: When the battery cables have been removed from the batteries, wrap the battery terminals and cable ends with electric tape to prevent accidental grounding. The ground cables should always be disconnected first and replaced last.
Note: When the battery cables have been removed from the batteries, wrap the battery terminals and cable ends with electric tape to prevent accidental grounding. The ground cables should always be disconnected first and replaced last.
Section 06: ELECTRICAL
Note: In replacing batteries, only batteries of the same specification should be used. Refer to
“Specifications” at the end of this section for further details.
Caution: Ensure that connections are not reversed when reinstalling batteries, since damage to electrical system components will result.
When reinstalling batteries, battery connections must be tightened to 10-15 ft-lbf (13-20) N·m) and the nut on top of sliding tray to 45-55 in-lbf
(5-6 N·m). A torque wrench is required to ensure an accurate tightening torque.
Warning: To prevent possible electric shock or sparking, the battery master switch must be set to the “Off” position before tightening an electrical connection.
Note: A protective silicone free, coating should be applied on all terminals that have been disconnected. We recommend the use of Cortec
VCI-238 (Prévost #682460) on all electrical connections.
The batteries are located in the main power compartment.
1. Remove the two screws at the bottom of the plastic protective cover, then unscrew the two quarter turn nuts to remove the protective cover (Fig. 5)
Warning: To prevent possible electric shocks or sparking, the battery master switch should be in the "Off" position before disconnecting cables from the batteries (see paragraph "2.3 Battery master switch").
2. Remove the supports, and unscrew terminal nuts of each defective battery.
3. Remove battery cables from the batteries.
Note: When the battery cables have been removed from the batteries, wrap the battery terminals and cable ends with electric tape to prevent accidental grounding. The ground cables should always be disconnected first and replaced last.
4. Remove batteries.
5. Installation is the reverse of removal.
06-19
Section 06: ELECTRICAL
Note: When the battery cables have been removed from the batteries, wrap the battery terminals and cable ends with electric tape to prevent accidental grounding. The ground cables should always be disconnected first and replaced last.
Note: In replacing batteries, only batteries of the same specification should be used. Refer to
“Specifications” at the end of this section for further details.
Caution: Ensure that connections are not reversed when reinstalling batteries, since damage to electrical system components will result.
When reinstalling batteries, battery connections must be tightened to 13-15 ft-lbf (18-20) N·m) and the nut on top of sliding tray to 45-55 in-lbf
(5-6 N·m). A torque wrench is required to ensure an accurate tightening torque.
Warning: To prevent possible electric shock or sparking, the battery master switch must be set to the “Off” position before tightening an electrical connection.
Note: A protective silicone free, coating should be applied on all terminals that have been disconnected. We recommend the use of Cortec
VCI-238 (Prévost #682460) on all electrical connections.
4.1.3 Xl2-40, XL2-45E and XL2 45 Bus Shells
The batteries are located in the engine compartment R.H. side (Fig. 19).
1. Remove the tree (3) plastic protective cover retaining bolts. Remove the plastic protective cover.
2. Remove the support retaining bolt.
Warning: To prevent possible electric shocks or sparking, the 12 and 24 volts battery master switch should be in the "Off" position before disconnecting cables from the batteries (see paragraph "3.3 Battery Master Switch”).
3. Remove the support (if necessary, remove battery cables). To remove battery cables, unscrew terminal nuts and remove cables.
4. Remove battery cables from defective batteries.
Note: When the battery cables have been removed from the batteries, wrap the battery terminals and cable ends with electric tape to prevent accidental grounding. The ground cables should always be disconnected first and replaced last.
5. Remove defective batteries.
6. Installation is the reverse of removal.
Note: In replacing batteries, only batteries of the same specification should be used. Refer to
“Specifications” at the end of this section for further details.
Caution: Ensure that connections are not reversed when reinstalling batteries, since damage to electrical system components will result.
When reinstalling batteries, battery connections must be tightened to 13-15 ft-lbf (18-20) N·m) and the nut on top of sliding tray to 45-55 in-lbf
(5-6 N·m). A torque wrench is required to ensure an accurate tightening torque.
Warning: To prevent possible electric shock or sparking, the battery master switch must be set to the “Off” position before tightening an electrical connection.
Note: A protective silicone free, coating should be applied on all terminals that have been disconnected. We recommend the use of Cortec
VCI-238 (Prévost #682460) on all electrical connections.
Each of the 12 volt batteries used on the vehicle has the following rating:
• Reserve capacity: 180 minutes
• Cold cranking (amps): 625 @ 0 o F (-18 o C)
• Cold cranking (amps): 490 @ -20 o
F (-29 o
C)
• Weight (filled): 59 lb. (26,7 kg)
The reserve capacity is defined as the number of minutes a new, fully charged battery at 80 F
(26,6 C) can be discharged at 25 amperes and maintain a minimum of 1.75 volts per cell (10.5 volts total for one 12 volts battery). This rating can be used as a basis for determining how long a vehicle might run after an alternator failure.
06-20
The cold cranking rating is defined as the minimum discharge current a battery will deliver in amperes for 30 seconds at 0 F (-18 C) while maintaining a minimum of 1.2 volts per cell (7.2 volts total for one 12 volts battery). This rating can be used as a basis for comparing starting performance.
The maintenance-free battery has a strong ability to withstand the damaging effects of overcharge. The test indicator in the cover is used only to determine if the battery can be tested in case of a cranking problem.
The test indicator in the battery cover is to be used with accepted diagnostic procedures only.
It must not be used to determine if the battery is good or bad, charged or discharged. The test indicator is a built-in hydrometer in one cell that provides visual information for battery testing
(Fig. 28).
It is important when observing the test indicator, that the battery be relatively level and has a clean indicator top to see the correct indication.
Some lighting may be required in poorly lit areas. Under normal operation, two indications can be observed.
Section 06: ELECTRICAL
Green Dot Visible
Any green appearance is interpreted as a "green dot" , and the battery is ready for testing. On rare occasions, following prolonged cranking, the green dot may still be visible when the battery is obviously discharged. Should this occur, charge the battery as described under "Charging
Procedure" in "Battery Charging" later in this section.
Dark - Green Dot Not Visible
If there is difficulty cranking the engine, the battery should be tested as described in this section. On rare occasions, the test indicator may turn light yellow. In this case, the integral charging system should be checked. Normally, the battery is capable of further service; however, if difficult start has been reported, replace the battery. DO NOT CHARGE, TEST,
OR JUMP-START.
1. Check the outside of the battery for a broken or cracked cover or case that could permit loss of electrolyte. If obvious physical damage is noted, replace the battery.
2. Check for loose terminal posts, cable connections, damaged cables, and for evidence of corrosion. Correct conditions as required before proceeding with tests.
4.3.2 Removing Surface Charge
Disconnect cables from the battery and attach alligator clamps to the contact lead pad on the battery as shown in figure 30. Connect a 300 ampere load across the terminal for 15 seconds to remove surface charge from the battery.
This test is one means of checking the battery to determine its ability to function as required in the vehicle.
To make this test, use test equipment that will withstand a heavy electrical load from the battery, such as a carbon pile resistor or other suitable means.
1. Connect a voltmeter, ammeter, and a variable load resistance as illustrated in figure 29.
FIGURE 28: TEST INDICATOR
06096
06-21
Section 06: ELECTRICAL drop can be detected with a low-reading voltmeter as follows:
Warning: To prevent the engine from starting, the DDEC engine circuits, which are protected by breakers (CB-19, CB-20 and CB-21) located in the rear junction box, must be deenergized during these tests; afterward, depress black button to close circuit.
FIGURE 29: LOAD TEST
06064
Caution: Observe polarity of the meters and the battery when making connections, and select the correct meter range.
2. Apply a 290 amperes load to the battery for
15 seconds.
3. With an ammeter reading specified load, read voltage. The voltage should be at least
9.6 volts. Disconnect the load. If the voltmeter indicates 9.6 volts or more, the battery is good. If the voltmeter reading is less than 9.6 volts, replace the battery. This voltage is to be used for battery ambient temperatures of 70ºF (21ºC) and above. For temperatures below 70ºF (21ºC), refer to the following "Voltage and Temperature Chart" .
Voltage and Temperature Chart
Ambient Temperature Minimum Voltage
70ºF (21ºC) and above 9.6
60ºF (16ºC) 9.5
50ºF (10ºC) 9.4
40ºF (4ºC)
30ºF (-1ºC)
20ºF (-7ºC)
10ºF (-12ºC)
0ºF (-18ºC)
9.3
9.1
8.9
8.7
8.5
Note: The accuracy of this test procedure is dependent upon close adherence to the proper load, time and temperature specifications.
4.3.4 Testing Battery Cables
Check all cable ring terminals and connections to determine if they are in good condition.
Excessive resistance, generally caused by poor connections, produces an abnormal voltage drop which may lower voltage at the starter to such a low value that normal operation of the starter will not be obtained. An abnormal voltage
06-22
1. Check voltage drop between grounded
(negative) battery terminal and vehicle frame by placing one prod of the voltmeter on the battery terminal and the other on a good ground (unpainted surface) on the vehicle. With the starter cranking the engine at a temperature of 70ºF (21ºC), voltage reading should be less than 0.3 volt. If the voltage reading exceeds 0.3 volt, there is excessive resistance in this circuit.
2. Check voltage drop between the positive battery terminal and the starter positive terminal stud while the motor is operated. If the reading is more than 2.5 volts, there is excessive resistance in this circuit.
Note: If it is necessary to extend the voltmeter lead for this test, use a #16 (AWG) or larger wire.
3. Check voltage drop between the starter housing and a good ground on the vehicle.
The reading should be less than 0.2 volt.
Warning: Any procedure other than the following could cause personal injury or damages to the charging system resulting from battery explosion or electrical burns.
Wear adequate eye protection when working on or near the batteries. Ensure that metal tools or jumper cables do not contact the positive battery terminal (or a metal surface in contact with it) as a short circuit will result. Do not attempt to jump start a vehicle suspected of having a frozen battery because the battery may rupture or explode. Both the booster and discharged batteries must be treated carefully when using jumper cables. Follow exactly the procedure outlined later in this section, being careful not to cause sparks.
Section 06: ELECTRICAL
CHARGING
Warning: During charging of the batteries, an explosive gas mixture forms in each cell. Part of this gas escapes through the vent holes and may form an explosive atmosphere around the battery itself if ventilation is poor. This explosive gas may remain in or around the battery for several hours after it has been charged. Sparks or flames can ignite this gas causing an internal explosion, which may shatter the battery.
1. Do not smoke near a battery which is being charged or which has been recently charged.
2. Do not break live circuits at battery terminals because a spark usually occurs at the point where a live circuit is broken. Care must always be taken when connecting or disconnecting booster leads or cable clamps on chargers. Poor connections are a common cause of electric arcs, which cause explosions.
3. The electrical system on this vehicle is negative ground. Installing the batteries with the positive terminals grounded or incorrect use of the booster battery and jumper cables will result in serious damage to the alternator, batteries and battery cables.
The batteries used on this vehicle can be charged either on or off the vehicle; however, when they are removed from the vehicle, it is recommended that an adapter kit, which is available from any "A/C DELCO" dealer, be used in charging sealed-terminal batteries. Use the booster block to charge the batteries when they are left on vehicle and make sure that the main battery disconnect switch is set to the
“On” position.
The alligator clamps of the tester or charger must be placed between the terminal nuts and the lead pads of the terminal studs (Fig. 30) after the vehicle cables are detached. The alligator clamps should make firm contact with the lead pads.
FIGURE 30: ALLIGATOR CLAMPS AND BATTERY 06065
Note: If this connection cannot be made because of the alligator clamp design, the load value for testing must be reduced from 290 to
260 amperes.
On rare occasions, such as those that occur following prolonged cranking, the green dot in the test indicator may still be visible when the battery is obviously discharged. Should this occur, a boost charge of 20 amperes-hour is recommended. Under normal operating conditions, do not charge battery if the green dot is visible. The battery should never be charged if the test indicator (hydrometer) is clear or light yellow. If this occurs, replace the battery.
A charge rate between 3 and 50 amperes is generally satisfactory for any maintenance-free battery as long as spewing of electrolyte does not occur or the battery does not feel excessively hot (over 125ºF (52ºC)). If spewing or violent gassing of electrolyte occurs or battery temperature exceeds 125ºF (52ºC), the charging rate must be reduced or temporarily stopped to allow cooling and to avoid damaging the battery.
Battery temperature can be estimated by touching or feeling the battery case. The battery is sufficiently charged when the green dot in the built-in hydrometer is visible. No further charging is required. Shake or tilt the battery at hourly intervals during charging to mix the electrolyte and see if the green dot appears.
Warning: Always turn off the charger before connecting or disconnecting to a battery.
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Section 06: ELECTRICAL
Note: The charge rate must be doubled when the batteries are charged by the booster block, because of the series-parallel circuit.
Battery charging consists of a charge current in amperes for a period of time in hours. Thus, a
25 ampere charging rate for 2 hours would be a
50 ampere-hour charge to the battery. Most batteries, whose load test values are greater than 200 amperes, will have the green dot visible after at least a 75 ampere-hour charge. In the event that the green dot does not appear, replace the battery.
4.4.1 Battery Charging Guide
Fast Charging Rate
20 amps @ 3-3/4 hours
30 amps @ 2-1/2 hours
40 amps @ 2 hours
50 amps @ 1-1/2 hours
Slow Charging Rate
5 amps @ 15 hours
10 amps @ 7-1/2 hours
The time required for a charge will vary according to the following factors:
Size of Battery
For example, a completely discharged large heavy-duty battery requires more than twice the recharging time of a completely discharged small passenger car battery.
Temperature
For example, a longer time will be needed to charge any battery at 0
(27 o o
F (-18 o
C) than at 80 o
F
C). When a fast charger is connected to a cold battery, the current accepted by the battery will be very low at first, then in time, the battery will accept a higher rate as it warms.
State of Charge
For example, a completely discharged battery requires more than twice as much charge than a half-charged battery. Since the electrolyte is nearly pure water and a poor conductor in a completely discharged battery, the current accepted is very low at first. Later, as the charging current causes the electrolyte acid content to increase, the charging current will likewise increase.
Charger Capacity
For example, a charger which can supply only 5 amperes will require a much longer period of charging than a charger that can supply 30 amperes or more.
06-24
4.4.2 Emergency Jump Starting With Auxiliary
(Booster) Battery
Warning: Do not jump start vehicles equipped with maintenance-free batteries if the test indicator is light yellow.
Both booster and discharged batteries should be treated carefully when using jumper cables. A vehicle with a discharged battery may be started by using energy from a booster battery or the battery from another vehicle.
Warning: Jump starting may be dangerous and should be attempted only if the following conditions are met:
The booster battery or the battery in the other vehicle must be of the same voltage as the battery in the vehicle being started, and must be negative grounded.
If the booster battery is a sealed-type battery without filler openings or caps, its test indicator must be dark or a green dot must be visible. Do not attempt jump starting if the test indicator of the booster battery or the discharged battery has a light or bright center.
Warning: Follow the procedure exactly as outlined hereafter. Avoid making sparks.
1. Wear eye protection and remove rings, watches with metal bands and other metal jewelry.
2. Apply parking brake and place the transmission shift lever or push-button pads in Neutral (N) position in both vehicles. Turn off lights, heater and other electrical loads.
Observe the charge indicator. If the indicator in the discharged battery is illuminated, replace the battery. Do not attempt jump starting when indicator is illuminated. If the test indicator is dark and has a green dot in the center, failure to start is not due to a discharged battery and the cranking system should be checked. If charge indicator is dark but the green dot does not appear in center, proceed as follows:
3. Connect one end of one red jumper cable to the positive (+) terminal of the booster power source and the other end to the positive (+) post of the booster power block, located in the main power compartment or in the engine compartment R.H. side (refer to fig. 5 and 18).
4. Connect one end of the remaining negative jumper cable (black) to the negative (-)
terminal of the booster power source, and the other end of the black jumper cable to the negative (-) post of the booster power block.
5. Make sure the clips from one cable do not inadvertently touch the clips on the other cable. Do not lean over the battery when making connections. The ground connection must provide good electrical conductivity and current carrying capacity.
6. Start the engine in the vehicle that is providing the jump start. Let the engine run for a few minutes, then start the engine in the vehicle that has the discharged batteries.
7. When removing the jumper cables, perform the above procedure exactly in reverse order, and replace protective caps on booster block terminals.
Warning : Any procedure other than the above could result in personal injury, property damage due to battery explosion, or damage to the charging system of the booster vehicle or of the boosted vehicle.
Note: Jumper cables must withstand 500 cranking amperes. If cable length is 20 feet (6m) or less, use 2/0 (AWG) gauge wires. If cable length is between 20-30 feet (6-9m), use 3/0
(AWG) wires.
4.5 CLEANING AND INSPECTION
The external condition of the battery and the battery cables should be checked periodically.
The top of the battery should be kept clean and the battery hold-down clamp bolts should be kept properly tightened. For best results when cleaning the battery, wash first with a diluted solution of ammonia or soda to neutralize any acid present, then wash out with clean water.
The battery hold-down bolts should be kept tight enough to prevent the batteries from moving, but they should not be tightened to the point that excessive strain is placed on the battery hold-down cover (proper tightening torque: 45-
55 in•lbf (5-6 N•m).
To insure good contact, the battery cable ring terminals should be tight on the battery posts. If the posts or cable ring terminals are corroded, the cables should be disconnected and the posts and clamps cleaned separately with a soda solution and a wire brush. Install cable ring terminals on battery posts and tighten to a
Section 06: ELECTRICAL torque of 10-15 ft•lbs (13-20 N•m). Replace protective caps to prevent corrosion and sparks.
4.6 COMMON CAUSES OF BATTERY
FAILURE
When a battery fails, the cause of failure may be related to something other than the battery. For this reason, when a battery failure occurs, do not be satisfied with merely recharging or replacing the battery. Locate and correct the cause of the failure to prevent recurrence. Some common external causes of battery failure are as follows:
1. A defect in charging system such as high resistance or a faulty alternator or regulator.
2. A malfunction within the 12 volts system
(equalizer).
3. Overloads caused by a defective starter or excessive use of accessories.
4. Dirt and electrolyte on top of the batteries causing a constant drain.
5. Hardened battery plates, due to battery being in a low state of charge over a long period of time.
6. Shorted cells, loss of active material from plates.
7. Driving conditions or requirements under which the vehicle is driven for short periods of time.
8. A constant drain caused by a shorted circuit such as an exposed wire or water infiltration in junction boxes causing ground fault.
9. Extended operation of preheating system with engine not running.
10. Failing to close disconnect switches during the night.
4.7 TROUBLESHOOTING
If a battery is known to be good and then has not performed satisfactorily in service for no apparent reason, the following factors may reveal the cause of trouble: switches inadvertently left on overnight.
2. Defects in the charging system, such as high wiring resistance, faulty alternator, regulator or battery equalizer.
3. A vehicle electrical load exceeding the alternator (or battery equalizer) capacity,
06-25
Section 06: ELECTRICAL with the addition of electrical devices, such as CB radio equipment, a cellular phone or additional lighting systems.
4. Defects in the electrical system, such as shorted or pinched wires.
5. Extended driving at a slow speed while using many accessories.
6. Loose or poor battery cable-to-post connections, previous improper charging of a run-down battery, or loose hold-down clamp bolts.
7. High-resistance connections or defects in the cranking system.
5. ELECTRICAL SYSTEM MONITOR
This vehicle is equipped with an electronic device that monitors and detects abnormal alternator, voltage regulator, battery banks or battery equalizers conditions. The monitor is installed in the main power compartment (XL2-
45) (refer to fig. 5), in the battery compartment or in the engine compartment R.H. side (MTH).
The “Battery balance” and “Battery Hi/Lo” warning lamps connected to this module are mounted in the dashboard (refer to “Operator’s
Manual” for location). If a malfunction should occur, the monitor sends a signal to the driver through the warning light of the malfunctioning component. If the “Battery Hi/Lo” warning light is illuminated, check the 24 volt voltmeter to determine if the battery voltage is too high or too low.
Note: According to the battery charging condition, it is normal that "Battery Hi/Lo" warning light illuminates upon starting the engine and stays illuminated for a few seconds.
This is caused by the normal voltage drop of the battery during starting.
5.1 TELLTALE LIGHT DEFINITIONS
Battery Hi/Lo
Voltmeter drops below 24 V dc
• Check alternator output.
• Check voltage regulator.
• Check battery connections.
• Check battery cells.
• Check battery equalizer connections.
Voltmeter exceeds 30 V dc
• Check alternator output.
• Check voltage regulator.
• Check battery connections.
Battery Balance
Note: Allow at least 15 minutes to balance batteries after any corrective measure has been taken.
1. Batteries out of balance (difference greater than 1.5 volts between the two battery banks).
• Check battery equalizer connections.
• Check equalizer cables for proper gauge.
• Check battery connections.
2. Demand for 12 volt power exceeding rated amperage output of battery equalizers causing batteries to go out of balance.
• Reduce 12 volt load or install additional battery equalizer(s).
“Battery” Warning Light
This warning light is not controlled by the electronic monitor, but by the "R" terminal of the alternator using the normally-closed contact of relay R-33. If a voltage drop should occur in the charging system, the “Battery” telltale light will immediately illuminate to warn the driver. The
“Battery Hi/Lo” telltale light will illuminate if voltage drops below 24 V dc.
Refer to heading "Diagnosis of Charging System
Problems" later in this section, to determine weather the alternator or the voltage regulator is defective. Should the "Battery" telltale light illuminate while the 24 volt voltmeter keeps on giving a normal reading and the "Battery Hi/Lo" telltale light does not illuminate, the relay R-33 or its wiring is probably defective.
Caution: The relay R-33 should never be replaced with a relay provided with a suppressor diode on its coil as the output current (between
12 and 14 volts) at the alternator "R" terminal is not rectified, thus rendering the relay inoperative.
Note: When the "Battery" warning light illuminates, the "A/C & Heating" system shuts off in order to prevent battery discharge.
06-26
Section 06: ELECTRICAL
One or two 24 volt 140 amp., self regulated, belt driven, air-cooled BOSCH alternators may be used in the 24 volt electrical system (instead of the DELCO 24 volt 270 amp. alternator).
Change the brushes as per “Repair and Testing
Instructions for T1 Alternator 0120 69 552” every
100,000 miles (160 000 fm) or once every two years, whichever comes first.
Replace bearings as per “Repair and Testing
Instructions for T1 Alternator 0120 69 552” every
200,000 miles (320 000 fm) or once every four years, whichever comes first.
Refer to Bosh T1 Alternator Maintenance
Manual Annexed at the end of this section.
The 24 volt charging system consists of a belt driven, oil-cooled, brushless alternator, a 24 volt voltage regulator, an alternator relay and a 12 volt system that includes a 12 volt, 100 amp equalizer. The components used in this system are described under the applicable headings hereafter.
FIGURE 31: OIL CIRCULATION THROUGH ALTERNATOR
This oil-cooled alternator is self rectifying. All current carrying members, windings, built-in diodes, and field coils are stationary. The only moving component is the rotor. The alternator is a totally-enclosed unit, cooled and lubricated by engine oil. The oil inlet is on the diode end cover. The oil drains back into the engine crankcase through the drive end frame and drive adapter housing. This alternator should never
06066 be operated with the oil supply line disconnected. A continuous flow of engine oil through the alternator lubricates the bearings and cools the assembly. Four terminals are used on this alternator: the DC output terminal, two field terminals, and a 12 volt relay terminal. The alternator output voltage is regulated by a separate 24 volt regulator that controls the alternator field current (Fig. 31 and 32).
06-27
Section 6: ELECTRICAL
FIGURE 32: ALTERNATOR WIRING DIAGRAM (DELCO)
Note: The relay coils connected to the alternator “relay terminal” SHOULD NEVER BE
PROVIDED WITH A SUPPRESSOR DIODE as the output current at this terminal is not rectified, thus rendering relay inoperative.
Caution: The electrical system is NEGATIVE
GROUNDED. Connecting the batteries or a battery charger with the positive terminal grounded will endanger the alternator diodes and vehicle wiring by a high current flow. Burned wiring harnesses and burned “open” diodes will result. Always ensure that the alternator and battery polarities are matched prior to installation. THE ALTENATOR WILL NOT
REVERSE TO ACCEPT INVERSE POLARITY.
Also, do not ground or short across any of the alternator or regulator terminals.
Since there are no brushes, slip rings, or rubbing seals, the alternator requires no periodic maintenance other than the following:
Check alternator-to-engine mounting bolts for looseness and tighten to the proper torque.
Check all electrical connections for tightness and corrosion. Clean and tighten connections as necessary. Be sure wiring insulation is in good condition and that all wiring is securely clipped to prevent chafing of the insulation.
With the engine running, listen for noise and check the alternator for vibration. If the alternator is noisy or vibrates excessively, it should be removed for inspection and repair.
Ensure that battery terminals are clean and tight.
06067
8. CHARGING
TROUBLESHOOTING
SYSTEM
The troubleshooting of the charging system is made easier by the use of a 12 and a 24 volt voltmeter, “ Battery” , “Battery balance” and
“Battery Hi/Lo” telltale lights mounted in the dashboard (for location refer to the “Operator’s
Manual” ).
The definition of each warning light is explained under the “ELECTRICAL SYSTEM
MONITOR”
8.1 ALTERNATOR OR VOLTAGE
REGULATOR .
06-28
Section 6: ELECTRICAL
BAD PRACTICE. NEVER JUMP F1 FIELD
TERMINAL TO DC(+) TERMINAL
06068
DIAGNOSIS
Caution: Before checking the alternator, set the battery master switch to the OFF position.
5. Disconnect all diode flexible leads; i.e. three from the output terminal stud and three from the diode supports. See figure 20 for more details.
It is not necessary to disassemble completely the alternator to make electrical checks. All electrical checks are made at the diode end of the assembly without having to remove the rotor, drive end frame or bearing. If the electrical components are not defective but bearing replacement is necessary, this can be done at the drive end without having to disassemble the diode end of the unit.
The components in the alternator that require electrical checks are the field winding, the six diodes, and the stator winding.
Each diode may be checked for shorts and opens as follows:
1. Ensure the battery master switch is set to the “OFF” position.
Each diode may be checked for short or open circuits with an ohmmeter.
Note: The ohmmeter polarity may be determined by connecting its leads to the voltmeter leads. The voltmeter will read up-scale when the negative leads are connected together and the positive leads are connected together.
The polarity of the voltmeter leads may be determined by connecting the leads to the identified terminals on a battery.
Note: Use an ohmmeter with a single 1.5 volts cell. Most accurate reading will be determined when the 300 ohms value is calibrated to the center one-third of the scale. DO NOT USE high voltage, such as a 110 volts test lamp to check diodes.
2. Remove the pipe plug from underneath the end housing to drain the oil in the rectifier engine oil supply.
3. Remove the cap screws (7) and lock washers that attach the diode end cover to the end housing. Remove the end cover from the end housing.
Note: Do not operate the alternator unless this unit is completely reassembled.
4. Remove seal from the end housing, detach and remove “DC” and relay terminals, stud, insulating sleeves and O-rings.
06- 29
Section 6: ELECTRICAL
FIGURE 34: VIEW OF RECTIFIER END FRAME WITH COVER REMOVED
To check diodes mounted in the supports for short fields, connect the positive ohmmeter lead to each diode lead and the ohmmeter negative lead to each support as shown in "A", "B", and
"C" of figure 35. To check diodes mounted in the end frame for shorts, connect the ohmmeter positive lead to each diode lead and the ohmmeter negative lead to the end frame as shown in parts "D", "E", "F". The ohmmeter readings may vary considerably when checking diodes for shorts, but if the reading is 300 ohms or less, the diode is probably defective and should be replaced. A diode that reads 300 ohms or less will allow excessive reverse current from the battery. Replace defective diodes as explained later in this section.
To check the diodes mounted in the diode supports for open fields, connect the ohmmeter negative lead to each diode lead and the ohmmeter positive lead to each support as shown in parts “A”, “B”, and “C” of figure 36. To check the diodes mounted in end frame for shorts, connect the ohmmeter negative lead to each diode lead and the ohmmeter positive lead to the end frame as shown in parts “D”, “E” and
“F”. An infinite resistance reading indicates an open diode. Diodes can be replaced by following the procedure outlined under DIODE
REPLACEMENT”.
FIGURE 35: DIODE TESTING
06069
06070
06-30
FIGURE 36: DIODE TESTING 06071
When reinstalling diodes, torque to 9-11 ft•lbf
(12-15 N•m). Re-stake next to the threads in an arbor press with an 1/8 inch (3,2 mm) round punch. Press the punch with gradual pressure.
Do not strike as the shock may damage the diodes.
8.2.2 Field Winding Check
The field winding may be checked for shorts and opens with an ohmmeter. To check the field winding, connect the ohmmeter to field terminal and to ground. A resistance reading above normal indicates an open, and a reading less than normal indicates a short field. The normal resistance value is 3.0 to 3.3 ohms at 80
(27 o o F
C). An alternate method of checking is to place a battery of specified voltage, and an ammeter in series with the field winding. The current should register 7.2 to 8.3 amperes at 24 volts. Coil resistance is approximately 3.1 ohms.
Amperage readings, other than the above, indicate an open, grounded, or shorted field. A defective field coil can be replaced by removing the end frame on which the field terminal is located and then removing the four field coil mounting screws. See FIELD REPLACEMENT” for a detailed procedure.
8.2.3 Stator Winding Check
The stator winding may be checked for open and short fields with an ohmmeter as follows:
Section 6: ELECTRICAL
Open Fields
Connect the ohmmeter leads to two pairs of diode supports as shown in parts "A", "B", and
"C" of figure 37. Correct polarity of the leads must be observed. The ohmmeter should indicate a low resistance. If an infinite or a high resistance is measured in either one or both checks, the stator windings are open.
Ground
To check the stator windings for ground, connect an ohmmeter to the diode support and diode end frame as shown in part "C" of figure
37. The ohmmeter should indicate a very high or infinite resistance. If zero, or a very low resistance is measured, the windings are grounded.
Shorts
The stator windings are difficult to check for shorts without finely calibrated laboratory test equipment due to the very low resistance values of the windings. However, if all other alternator checks are satisfactory, yet the unit fails to perform to specifications, shorted stator windings are probable.
FIGURE 37: STATOR WINDING TEST
06072
The following replacement procedures are based on the assumption that the diode end cover is still off and diode leads were disconnected as explained earlier in this section.
06- 31
Section 6: ELECTRICAL
Note: When replacing a diode, make sure it is designed for a negative ground system. The diode can be identified by the symbol stamped on the diode case. The arrow must point toward the diode flexible lead.
To replace the three diodes that are mounted in the supports attached to the stator lead studs, it is necessary to remove the diode and support assembly. The two outer diode and support assemblies are identical and can be installed on either side. The center unit has a different support, with 2 inches (50,8 mm) between the mounting hole centers.
Note : The outer supports are provided with 2 ¼”
(57,15 mm) center holes.
8.3.1 Diode Replacement (in Support)
1. Remove nut with lock washer attaching the diode support to the stator lead stud.
2. Remove nut, lock washer, and flat washer attaching support to the small stud in the end frame.
3. Remove the diode and support assembly.
Then remove insert from small hole in support or from small stud in the end frame.
4. Remove nut and flat washer from diode mounting stud, then remove diode from the support.
5. Place a new diode in the support and install a flat washer and nut on the diode mounting stud. Hold the diode with a wrench placed over flats on the diode, while tightening nut on the mounting stud to a torque of 160-180 in•lbf (18-20 N•m).
6. Place diode and support assembly over the stator lead stud and the small mounting stud. Place insert over small stud inside the hole in the support. Install flat washer, lock washer, and nut on the small stud, and tighten to a torque of 22-25 in•lbf (2-3 N•m).
Install nut with lock washer on stator lead stud and tighten firmly.
8.3.2 Diode Replacement (in End Frame)
To remove diode, use a thin 1 inch open end wrench on flats of the diode case to unscrew diode from the end frame. Thread the new diode into the end frame and tighten to a torque of
160-180 in•lbs (18-20 N•m). If no other parts are to be replaced, refer to “DIODE END COVER
INSTALLATION” in this section.
06-32
Remove three diode and support assemblies from the end frame to provide access to the two lower field to end frame bolts.
2. Remove nut with lock washer and flat washer from three stator lead studs.
3. Remove the six bolts and lock washers attaching the diode end frame to the stator frame.
4. Separate the end frame from the stator frame, and remove the end frame and field assembly from the rotor while pushing the stator lead studs out of the end frame.
5. Remove nut, lock washer, flat washer, and insulating washer which secure the field lead terminal stud in the end frame. Push the stud out of the end frame.
6. Remove field terminal stud insulating bushing and seal from the end frame.
Remove insulating sleeve from the field terminal stud.
7. Remove the four bolts and lock washers attaching the field to the end frame.
8. To separate the field from the end frame, install four 3/8-24 x 3 inch bolts in place of the 3/8-24 x 2 inch bolts removed in step 7.
Thread bolts in to even heights. Support the end frame in an arbor press. Then, using a suitable press plate to exert pressure on all four bolt heads, press the field out of the end frame.
1. Position the field assembly on the end frame. Insert four 3/8-24 x 3 inch bolts through the end frame and thread into the field to keep holes aligned.
2. Support the end frame on an arbor press bed so that the diodes will not be damaged, and press the field into the end frame. Press in until shoulder on field coil bottoms against the end frame.
3. Remove the four guide bolts. Install four 3/8-
24 x 2 inch bolts, using new lock washers to attach the field to the end frame. Tighten bolts securely.
4. Place insulating sleeve in inner side of the field terminal stud hole in the end frame, and insert the terminal stud through the sleeve.
Place two O-rings and insulating bushing
over the terminal stud and push into hole in the end frame. Install insulating washer, flat washer, toothed lock washer, and nut on terminal stud. Tighten firmly.
5. Install each stator lead stud in the end frame as follows: Place insulating washer over the stud and insert the stud through the end frame. Place the insulating bushing over the stud and position in end frame hole. Install flat washer, lock washer, and nut on the stud. Tighten firmly.
6. Install three diode and support assemblies on the end frame as previously directed under “DIODE REPLACEMENT”.
7. Install a new seal in notch around end of the stator frame. Insert field into the rotor and position the end frame against the stator frame. Attach end frame to the stator frame with six bolts and lock washers. Tighten bolts firmly.
8. If no other parts require replacement, refer to "DIODE END COVER INSTALLATION" in this section to complete the assembly.
If tests performed under “Stator Winding
Checks” earlier in this section indicated an open circuit or short in the stator, the stator and frame assembly must be replaced.
8.6.1 Removal
1. Remove diode end frame and field assembly as previously directed in steps 1 through 4 under “Field Removal”.
2. Remove the six bolts and lock washers attaching the stator frame to the drive end frame.
3. Separate the stator frame from the drive end frame and remove the stator frame from the end frame and rotor.
8.6.2 Soldering Stator Terminal Leads
1. Using a wire brush, thoroughly clean the wire and terminal.
2. Silver solder the stator lead to the terminal using a torch.
3. Thoroughly clean the silver solder connection with a wire brush.
4. Using a high grade energized rosin flux, coat the silver soldered connection with a
80-20 tin-lead solder or pure tin solder to
Section 6: ELECTRICAL prevent deterioration of the silver solder by engine oil.
Note: The silver solder will provide the required mechanical strength, which will not be affected by temperature. The tin-lead solder will protect the silver solder connection from deterioration by engine oil.
8.6.3 Installation
1. Position new seal in notch around the drive end of the stator frame.
2. Position the stator and frame assembly over the rotor against the drive end frame. Attach the stator frame to the drive end frame with six bolts and lock washers. Tighten bolts firmly.
3. Install diode end frame and field assembly as directed in steps 5, 6 and 7 under
“installation”.
4. Install rectifier end cover as directed later.
8.7 DIODE END COVER INSTALLATION
1. Make sure all diodes are properly installed and securely tightened. Leads from diodes threaded into the end frame must be securely attached to the diode supports. The relay terminal lead must also be attached to the left diode support.
2. Connect leads from the three diodes mounted in supports to the output terminal stud. Tighten the attachment screw firmly.
Place insulating bushing over relay terminal stud.
3. Place a new seal in the diode end frame.
4. With the end cover in place against the end frame, install the cap screws and lock washers. Tighten the cap screws evenly and firmly.
5. Make sure the drain plug is installed in bottom of the end cover and securely tightened.
8.8 ALTERNATOR REMOVAL (DELCO)
1. Place "Starter Selector Switch" in engine compartment to the "OFF" position.
2. Place the battery master switch to the “OFF” position.
3. Remove alternator drive belt (see
“ALTERNATOR DRIVE BELT”).
06- 33
Section 6: ELECTRICAL
Note: When reinstalling drive belt, it is important to set the belt tension correctly. (refer to the appropriate heading later in this section).
4. Scratch off protective sealer from electrical connections (relay, field and positive terminals). Refer to figure 38.
FIGURE 38: ALTERNATOR (HOSES AND WIRES)
06341
Note: After reconnecting electrical wires, it is important to cover terminals with protective sealer (Prévost #680745).
5. Disconnect wire #25 from the relay terminal, wire #107 from the field “F1” terminal and disconnect battery cable from the positive
“+” terminal on the diode end cover. Tag wires removed to ease identification at time of installation. Refer to figure 38.
6. Disconnect oil supply line and vent hose from top of alternator (Fig. 38) and tape lines to prevent entry of foreign matter.
Disconnect oil drain hose from bottom of alternator (Fig. 39) and tape line to prevent entry of foreign matter.
FIGURE 39: ALTERNATOR RETAINING BOLTS AND
WASHERS 06350
7. Remove the four bolts and lock washer retaining alternator (refer to fig. 39).
06-34
Warning: Alternator weights approximately 154 lbs (70 kg). Another person is required to take the alternator out of the engine compartment.
8.8.1 Disassembly of Alternator
After diode, field and stator winding checks, the alternator can be disassembled to repair a faulty component, such as field or stator, or to proceed with bearing or rotor replacement. Perform the following steps to disassemble the alternator:
1. Remove nuts and washers from "DC" terminal on diode end frame.
2. Separate the diode cover plate from the diode end frame by removing the mounting screws.
3. Remove the washer, nut and lock washer attaching the diode supports to the end frame, the three screws connecting the diode leads to the diode supports, and the three nuts which attach the stator studs to the diode supports.
4. Separate the diode support assemblies from the diode end frame, and the three nuts that connect the studs to the diode end frame.
5. Mark the position of the drive end frame and diode frame with respect to the stator assembly so that the parts can be reassembled in the same position.
6. Detach the diode end frame and field assembly from the stator assembly by removing the attachment screws.
7. Separate the field assembly from the diode end frame by removing the four attachment screws.
8. Separate the rotor assembly and drive end frame from the stator assembly by removing the attaching screws.
9. Remove the shaft nut and washer, and the pulley. Press the rotor shaft out of the drive end frame.
10. Remove the retainer plate and pull the bearings from the drive end frame.
8.8.2 Alternator Cleaning and Inspection
Whenever the alternator is disassembled, it should be cleaned and inspected.
Cleaning
If sludge has accumulated on the stator, a light mineral oil should be used to clean it.
Inspection
When the alternator has been disassembled to the extent that the stator is exposed, the stator should be checked for the following: b) Proper spacing of conductors so that “near shorts” do not exist. c) Proper phase lead placement. d) Strong conductor and cross-over welds
8.8.3 Bearing or Rotor Replacement
Whenever the rotor and drive end frame are disassembled for any reason, the single-row ball bearing must be replaced with a new one due to the probability of damage during disassembly.
Removal and Disassembly
1. If the pulley was not removed from the rotor shaft at time of alternator removal, remove the nut and flat washer from the shaft and pull the pulley off the shaft.
2. Remove the six bolts and lock washers attaching the drive end frame to the stator frame. Separate the drive end frame from the stator frame. Remove the drive end frame and support assembly.
3. Support the drive end frame in an arbor press so that the rotor can be pressed down out of the end frame. Using a suitable adapter against the end of the rotor shaft that will pass through the inner race of the double-row ball bearing, press the rotor down out of the end frame and bearings.
Since the single-row bearing outer race is held in the end frame by the retainer plate, and the inner race is a press fit on to the rotor shaft, the bearing will probably be damaged when the shaft is pressed out and need to be replaced with a new part.
4. Remove the six screws attaching the bearing retainer plate to the drive end frame.
Remove the retainer plate, the single-row bearing and the bearing spacer from the end frame.
Section 6: ELECTRICAL
5. Support the drive end frame in an arbor press with the double-row bearing down, so that the bearing can be pressed down out of the end frame. Using a suitable driver that will exert a force on the bearing outer race, press the bearing out of the end frame.
6. Remove the rubber bearing clamp from groove in the end frame.
Assembly and Installation
1. Install a new single-row ball bearing into inner side of the drive end frame. Install the bearing retainer plate and attach with six screws. Stake screws in place after tightening.
2. Position the rubber bearing clamp in the groove in bearing bore of the drive end frame. Lubricate the clamp to permit the bearing to be pressed in without dislodging or damaging the clamp.
3. Position the rotor in an arbor press with the shaft end up. Install the drive end frame and single-row bearing assembly over the rotor shaft. Using a driver over the rotor shaft, which will exert a force on the bearing inner race, press the bearing onto the shaft until it bottoms against the rotor.
4. Install bearing spacer over the rotor shaft.
Position the double-row bearing over the rotor shaft at end frame bore. Using an adapter that will exert a force on both the inner and outer races of the bearing, press the bearing onto the shaft and into the end frame until the inner race bottoms against the bearing spacer.
5. Place a new seal around the drive end of the stator frame.
6. Insert the rotor between the stator and field, and position the drive end frame against the stator frame. Attach the end frame to the stator frame with six bolts and lock washers.
Tighten the bolts to a torque of 5 to 5.4 ft•lbf
(6-7 N•m).
Caution: When replacing the alternator on the vehicle, ensure that an alternator with the proper drive ratio is used. Installation of an alternator with any other drive ratio will result in severe and costly damage to the alternator and engine.
Reassembly is the reverse of disassembly.
06- 35
Section 6: ELECTRICAL
Note: When tightening the outside nut on the
“DC” output terminal, torque the nut to 30-35 ft•lbf (41-47 N•m). The lower nut should be supported while doing so.
When reinstalling diodes, tighten to a torque of
9-11 ft • lbf (12-15 N • m).
When removed from the engine, the alternator may be checked without circulating oil on a test bench, providing the output is limited to 100 amperes or less. The alternator may be bench tested without circulating oil at outputs exceeding 100 amperes, as long as the period of operation is limited to less than 15 seconds.
Caution: Operating the alternator at outputs greater than 100 amperes without adequate oil circulation for periods exceeding 15 seconds, will cause the alternator to overheat, resulting in damage to the winding and diodes.
If the alternator is to be operated at an output greater than 100 amperes for longer than 15 seconds, circulating oil must be provided. SAE
30 engine oil must be applied to the connection on the diode end cover at a pressure of 35 psi and at a temperature of 60 o
104 o
F to 220 o
F (16 o
C to
C). This will provide an oil flow of about one gallon per minute.
To check the alternator on a test bench, make electrical connections as shown in figure 33.
Make sure the negative battery terminal is connected to the alternator frame.
8.9 ALTERNATOR DRIVE BELT
Removal
1. Insert a ¾‘’ socket drive into one of the tensioning arm opening (Fig. 40).
2. Twist the tensioning arm to slacken belt.
FIGURE 40: ALTERNATOR DRIVE BELT
06407
9. VOLTAGE REGULATOR (DELCO)
The 24 volt regulator used with Delco alternator is located in the engine compartment R.H. side
(MTH).
Installation
Installation of the alternator drive belt is the reverse of removal.
8.9.1 Adjustment
Correct belt tension is required to maximize belt life. The tensioning arm maintains proper belt tension, no adjustment is required.
Check for wear and proper tension every 6,250 miles (10 000 km) or twice a year, whichever comes first.
06-36
FIGURE 41: VOLTAGE REGULATOR
06408
The transistor regulator illustrated in figure 41 is an assembly mainly consisting of diodes, capacitors, resistors and transistors. These components are mounted on a printed circuit panel board to form a completely static unit containing no moving parts. Regulators of this type have only four terminals which are identified "GND." (ground), "FLD" (field) "BAT"
(battery) and “IGN” (ignition).
The regulator components work together to limit the alternator voltage to the preset value by controlling the alternator field current. This is the only function that the regulator performs in the charging system.
The voltage at which the alternator operates is determined by the regulator adjustment. Once adjusted, the alternator voltage remains constant. The regulator is unaffected by length of service, changes in temperature, or changes in alternator output and speed.
A typical wiring diagram of a negative ground system is illustrated in figure 42. This diagram shows only the basic charging system components. It does not show any components such as the control relays. Refer to “Charging system” wiring diagram, in “Wiring diagrams” for the electric circuits and connections.
Voltage regulator maintenance
The voltage regulator is a service-free electronic unit. When it fails, it should be replaced. The following procedure must be used:
Caution: Set the battery master switch to the
“OFF” position.
• Open the engine compartment R.H. side door in order to get access to the voltage regulator;
• Unscrew the electrical cable connectors;
• Unscrew the voltage regulator unit;
• Install a new voltage regulator by reversing the procedure.
Section 6: ELECTRICAL
Note: For information about BOSCH alternator and voltage regulator, refer to technical publication "Repair and Testing Instructions for
T1 Alternator 0120 689 552".
Trouble in the electrical system will usually be indicated by one of two conditions: an undercharged or an overcharged battery. Either condition can result from an improper voltage regulator setting:
Checking Battery Voltage
The absence of gas production during the continuous appearance of the green dot in the battery’s built-in hydrometer indicates that the voltage setting is satisfactory. Check the following conditions:
Checking Voltage Regulator Setting
1. To check the voltage setting, connect a voltmeter across the “POS” and “NEG” terminals on the regulator, and an ammeter to the “C” terminal on the alternator. Refer to figure 43.
REGULATOR
FLD
GND BAT
IGN
BATTERY
JUNCTION BOX
SWITCH
FIGURE 42: TYPICAL WIRING DIAGRAM OF A NEGATIVE
GROUND SYSTEM
06415
F
DC
VOLTMETER
ALTERNATOR
BATTERY
TEST
AMMETER
FIGURE 43: REGULATOR VOLTAGE SETTING
06416
2. Operate the engine at approximately 1000 rpm (about 2300 alternator rpm), with accessories on, to obtain an alternator output of 20-200 amperes.
3. Note the voltage setting. It should be steady at 27.5 volts.
4. If not, the desired setting can be obtained by removing the plug from the voltage regulator cover and slightly turning the adjusting screw inside the regulator. Turn the adjusting screw clockwise to increase the
06- 37
Section 6: ELECTRICAL voltage setting or counterclockwise to decrease it. See figure 44 for details.
Adjusment Screw
FIGURE 44: ADJUSTING REGULATOR VOLTAGE
SETTING
06418
Note : If regulator voltage cannot be adjusted to the specified setting, remove the regulator and repair or replace it as necessary.
If the voltage setting is steady and reasonably close to the specified value and the battery is undercharged, raise the setting by 0.3 volt, then check for an improved battery condition over a minimum service period of 48 hours. If the voltage cannot be adjusted to the desired value, the alternator should be checked as follows:
1. Stop alternator, turn off all accessories and disconnect battery ground cable.
2. Disconnect all leads from the regulator and from the alternator field. Do not allow leads to touch ground.
3. Connect a voltmeter and an ammeter in the circuit at the alternator "DC" terminal.
4. Connect a jumper lead from the alternator
"DC" terminal to the alternator field terminal.
REGULATOR
FLD
GND BAT
IGN
BATTERY
JUNCTION BOX
SWITCH
CARBON
PILE
LEADS
DISCONNECTED
JUMPER
LEAD
TEST AMMETER
F
DC
ALTERNATOR
BATTERY
VOLTMETER
FIGURE 45: REGULATOR VOLTAGE TEST
(UNDERCHARGED BATTERY)
06417
5. Connect a carbon pile resistor load across the battery. Turn to the "Off" position.
6. See figure 45 for wiring connections.
7. Reconnect battery ground cable
8. Turn on all vehicle accessories.
9. Operate alternator and adjust carbon pile resistor load as required to check for rated output as given in Delco-Remy Service
Bulletin 1G-187 or 1G-188.
10. Check the alternator field winding as follows:
Disconnect the lead from the field terminal and connect an ohmmeter from the field terminal to ground. A resistance reading above normal indicates an open field, and a resistance reading less than normal indicates a shorted or grounded field. The normal resistance can be calculated by dividing the voltage by the field current published in Delco-Remy Service Bulletin
1G-186, 1G-187, or 1G-188. The normal resistance value should be at or near midscale on the ohmmeter for accuracy. An alternate method of checking is to connect a battery of specified voltage and an ammeter in series with the field winding, and compare readings with published specifications in
Delco-Remy Service Bulletin 1G-186,
1G-187, or 1G-188. An alternator is defective if it does not produce rated output or if field windings are faulty. If the alternator provides rated output, and field windings check satisfactorily, the regulator should be checked as covered under "Regulator
Checks".
If the voltage setting as checked above is steady and reasonably close to the specified value, lower the setting by 0.3 volt and check for an improved battery condition over a minimum service period of 48 hours. If the voltage cannot be adjusted to the desired value, proceed as follows: where the alternator field is grounded internally in the alternator as shown in figure 42 a shorted or grounded field or a defective regulator can cause an overcharged battery.
The field winding can be checked as covered in paragraph “Undercharged Battery”. If the field winding is found to be correct, the alternator is not defective, and the regulator should be checked as covered under “Regulator Checks”.
Separate the cover from the base, and remove the panel assembly from the cover. Carefully
06-38
note the location of all washers and lock washers.
The component parts are keyed to figure 42.
Before making electrical checks, visually inspect the components and make sure all soldered connections are secure. Various electrical checks with an ohmmeter can be made to determine which components are defective.
The ohmmeter must be accurate, and should be a scale-type meter with a 1.5 or 3 volt cell. Most digital ohmmeters cannot be used to check semiconductors. However, some digital ohmmeters are specially designed to test semiconductors and can be used to test components in the regulator. Consult the ohmmeter’s manufacturer for specifications concerning the capabilities of the ohmmeter.
It is important that all of the following checks be made. If a defective part is found, replace it before proceeding with the remaining checks.
Be sure to make all the checks since more than one component may be defective.
A defective regulator can be repaired according to the following methods:
A) By changing the printed circuit board in the regulator. Unscrew the retaining screws on the printed circuit and remove it. Install a new printed circuit board. This method is the most commonly used.
B) By removing any retaining screws involved and unsoldering the connections. When resoldering, limit solder time to a minimum as excessive heat may damage the printed circuit board and component parts. However good soldered connections are essential for satisfactory operation. A resin core 63% tin
37% lead solder with a 360 o
F (182 o
C) melting point is recommended along with a soldering iron rated at 50 watts or less. Use extreme care to avoid overheating. Before checking the printed circuit board, remove transistor TR1, which must be checked separately. Connect the ohmmeter as shown in figure 46, and then reverse the ohmmeter leads to obtain two readings on the same component. Use the middle scale on scale-type meters on which the 300 ohm value should be within, or nearly within, the middle third of scale.
Capacitors C1 and C2 = The ohmmeter should read high and low on each capacitor. If not, replace capacitor.
Diodes D1, D2 and D3 = Each diode should give one high and one low reading. If not, replace diode.
Resistor R2 = Turn voltage adjustment screw
(identified in figure 44) with ohmmeter
Section 6: ELECTRICAL connecting each way. Reading should change as slotted screw is turned. If not, replace R2.
Transistor TR1 = See figure 46. Use the low scale. Each of the three checks should read low and high. If not, replace TR1.
FIGURE 46: CHECKING TRANSISTOR TR1
FIGURE 47: CHECKING TRANSISTOR TR2
After repair, the regulator must be adjusted to the desired voltage setting. Follow the procedure under “Checking Voltage Regulator
Setting”. Slowly turn the adjusting screw full range and observe the voltmeter to ensure that the voltage is being controlled, then, while still turning, slowly adjust to the desired setting.
10. BATTERY EQUALIZER
Battery equalizer troubleshooting guide and owner’s manual (60 and 100 amps) are annexed at the end of this section.
Refer to “Electrical Compartments and Junction
Box” of this section, for location.
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06081
Transistor TR2 = Change the ohmmeter to use the low scale. EB should read low and high. BC should read low and high. EC should both read high. If not, replace TR2. See figure 47.
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Section 6: ELECTRICAL
11. STARTER
The starter has a shift lever and solenoid plunger that are totally enclosed to protect them from exposure to dirt, icy conditions and splashing.
Positive lubrication is provided to the bronze bushing located in the commutator end frame, in the lever housing and in the nose housing, by an oil-saturated wick that projects through each bushing and contacts the armature shaft.
The clutch is a "Positork" drive type, that meshes with the ring gear by the action of the solenoid. Once engaged, the clutch will not disengage during intermittent engine firing. That prevents damage to pinion and ring gear teeth.
The pinion remains engaged until starting is assured and the solenoid circuit is interrupted.
Refer to figure 48 for more details.
11.1 MAINTENANCE
All wicks and oil reservoirs should be saturated with SAE 10 oil, and the splines underneath the clutch should be lubricated with a light coating of
SAE 10 oil. Other than normal periodic lubrication and keeping cable connections clean and tight, the starter should require no periodic maintenance. However, under normal operating conditions, the starter should be disassembled, inspected, cleaned and tested at time of engine overhaul.
11.2 TROUBLESHOOTING
Failure of the starter to crank the engine at normal speed may be due to a defective battery, worn battery cables, poor connections in the cranking circuit, defective engine starting switch, low temperature, condition of the engine or a defective starter. To determine if the starter is the problem, it will first be necessary to check the batteries, the cranking circuit, the magnetic switch, the solenoid and the control switch.
To obtain full performance data on a starter, or to determine the cause of abnormal operation, the starter should be subjected to the following tests. These tests are performed with the starter removed from the engine. Check the armature for freedom of rotation by prying on the pinion with a screwdriver. Tight bearings, a bent armature shaft, or a loose pole shoe screw will prevent the armature from turning freely. Failure of the starter to perform according to specifications will require disassembly of the motor for further checks and adjustments.
However, if the armature does rotate freely, the motor should be given a no-load test before disassembly.
Caution: Never operate the starter more than
30 seconds at a time without pausing to allow it to cool for at least 2 minutes. Overheating, caused by excessive starting, will seriously damage the starter.
FIGURE 48: TYPICAL STARTER CROSS SECTION
11.2.1 No-Load Test
Before disassembly of the starting motor, the following check of starting motor operation should be done to determinate any condition that may require special attention during
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06147 overhaul. Make test connections to the starting motor as in figure 49.
Connect the starting motor in series with fully charged batteries to give 24 volts, an ammeter capable of reading several hundred amperes
and a variable resistance. Also connect a voltmeter as illustrated in figure 49 from the solenoid motor (M) terminal to the starter frame.
A rpm indicator is necessary to measure armature speed. Proper voltage can be obtained by varying the resistance unit.
FIGURE 49: STARTING MOTOR NO-LOAD TEST
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No-load test results
1. Rated current draw and no-load speed indicate normal condition of the starter.
2. Low free-speed and high current draw indicate the following: a) Excessive friction. Tight, dirty, or worn bearings, bent armature shaft, or loose pole shoes allowing the armature to drag. b) Shorted armature. This can be further checked on a growler after disassembly of the starter. c) Grounded armature or fields. Check again after disassembly.
3. Failure of the starter to operate with high current draw indicates the following: a) A direct ground in the terminal or fields. b) “Frozen” bearings. This may be determined by turning the armature by hand.
4. Failure to operate with no current draw indicates: a) Open field circuit. This can be checked after starter disassembly by inspecting internal connections and tracing circuit with a test lamp.
Section 6: ELECTRICAL b) Open armature coils. Inspect the commutator for badly burned bars after disassembly. c) Broken brush springs, worn brushes, high insulation between the commutator bars or other causes which would prevent good contact between the brushes and commutator.
5. Low no-load speed and low current draw indicate high internal resistance due to poor connections, defective leads, dirty commutator and causes listed previously in condition 4.
6. High free-speed and high current draw indicate shorted fields. If shorted fields are suspected, replace the field coil assembly and check for improved performance.
11.2.2 Lock-Torque Test
A variable resistance with a high current capacity should be used. The starter should be securely mounted and brake arm hooked to the drive pinion. When specified current is applied, the torque can be computed from the reading on the scale. A one foot brake arm will directly indicate foot-pounds.
Warning: This test requires extreme caution.
Follow instructions carefully.
11.3 DISASSEMBLY
Normally, the starter should be disassembled only far enough to make repairs or to replace the defective parts. As a precaution, it is suggested that safety glasses be worn when disassembling or assembling the cranking motor. Proceed as follows:
1. Note the relative position of the solenoid, lever housing, and nose housing so the motor can be reassembled in the same manner.
2. Disconnect field coil from the solenoid motor terminal, and lead from the solenoid ground terminal.
3. On motors with brush inspection plugs, remove the plugs and then remove the brush lead screws. This will disconnect the field leads from the brush holders.
4. Remove the attaching bolts and separate the commutator end frame from the field frame.
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Section 6: ELECTRICAL
5. Separate the nose housing and field frame from the lever housing by removing attaching bolts.
6. Remove armature and clutch assembly from lever housing.
7. Separate solenoid from the lever housing by pulling apart.
11.3.1 Cleaning
The driving mechanism armature and fields should not be cleaned in a degreasing tank, or with grease dissolving solvents, since these would dissolve the lubricants in the drive mechanism and damage the insulation in the armature and field coils. All parts, except the drive, should be cleaned with mineral spirits and a brush. The drive can be wiped with a clean cloth.
If the commutator is dirty, it may be cleaned with
No. 00 sandpaper.
Caution: Never use emery cloth to clean the commutator.
11.3.2 Armature Servicing
If the armature commutator is worn, dirty, out of round, or has high insulation, the armature should be put in a lathe so the commutator can be turned down. The insulation should then be cut 1/32" (0,79 mm) wide and 1/32" (0,79 mm) deep, and the slots cleaned out to remove any trace of dirt or copper dust. As a final step in this procedure, the commutators should be sanded lightly with No. 00 sandpaper to remove any burrs left as a result of the undercutting procedures.
The armature should be checked for opens, short circuits and grounds as follows:
Open Circuit Test
Open circuits are usually caused by excessively long starting periods. The most likely place for an open circuit to occur is at the commutator riser bars. Inspect the points where the conductors are joined to the commutator bars for loose connections. Poor connections cause arcing and burning of the commutator bars as the starter is used. If the bars are not too badly burned, repair can often be performed by resoldering the leads in the riser bars (using rosin flux), and turning down the commutator in a lathe to remove the burned material.
Caution: Do not undercut the insulation between the commutator segments after turning down the commutator.
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Short Circuit Test
Short circuits in the armature are located by means of a growler. When the armature is revolved in the growler with a steel strip such as a hacksaw blade held above it, the blade will vibrate above the area of the armature core in which the short circuit is located. Short circuits between bars are sometimes produced by brush dust or copper between the bars. These short circuits can be eliminated by cleaning out the slots.
Ground Test
Grounds in the armature can be detected by the use of a 110 volts test lamp and test points. If the lamp lights when one test point is placed on the commutator with the other point on the core or shaft, the armature is grounded. Grounds occur as a result of insulation failure, which is often brought about by overheating of the starter produced by excessively long starting periods, or by accumulation of brush dust between the commutator bars and the steel commutator ring.
11.3.3 Field Coil Checks
The field coils may be checked for grounds and opens by using a test lamp.
Grounds
If the motor has one or more coils normally connected to ground, the ground connections must be disconnected during this check.
Connect one lead of the 110 volts test lamp to the field frame and the other lead to the field connector. If the lamp lights, at least one field coil is grounded, and it must be repaired or replaced.
Opens
Connect test lamp leads to ends of field coils. If lamp does not light, the field coils are open.
11.3.4 Field Coil Removal
Field coils can be removed from the field frame assembly by using a pole shoe screwdriver. A pole shoe spreader should also be used to prevent distortion of the field frame. Careful installation of the field coils is necessary to prevent shorting or grounding of the field coils as the pole shoe is tightened into place. Where the pole shoe has a long lip on one side and a short lip on the other, the long lip should be assembled in the direction of armature rotation so it becomes the trailing (not leading) edge of the pole shoe.
Section 6: ELECTRICAL
11.3.5 Reassembly
Reassembly is the reverse of disassembly. To reassemble the end frame with brushes on to the field frame, pull the armature out of the field frame just far enough to permit the brushes to be placed over the commutator. Push the commutator end frame and the armature back against the field frame.
The recommended torque for the cross-slotted pole shoe screws is 25-35 ft•lbf (34-47 N•m).
The electric cable connector is fixed with a nut tightened to 20 ft•lbf (27 N•m) and a jam nut tightened to 27 ft•lbf (37 N•m).
Pinion clearance should be checked after reassembly of motor to ensure the clearance is within specifications. To check pinion clearance
(starter off engine), first disconnect the motor field connector from the solenoid motor terminal.
Connect 24 volt battery with the positive battery lead to the solenoid switch terminal (5), and the negative battery lead to the grounded (G) solenoid terminal. Momentarily flash a jumper lead from the solenoid motor terminal to the grounded (G) solenoid terminal. The pinion gear will now shift into cranking position and remain that way until the battery is disconnected. Push the pinion or drive back towards the commutator end to eliminate slack movement. Measure the distance between pinion and pinion stop. This should be 23/64" ± 1/32" (9,5 mm ± 0,79 mm).
Pinion clearance is adjusted to these limits by turning the solenoid shaft nut after removing access plug in shift housing. See figure 50.
FIGURE 50: PINION CLEARANCE
The starter solenoid allows the starter pinion to mesh with the flywheel ring gear and also closes the electric circuit to energize the starting motor.
There are two windings in the solenoid: a pull-in winding and a hold-in winding. Both windings are energized when the external control switch is closed. They produce a magnetic field that pulls the plunger in so that the drive pinion is allowed into mesh, and the main contacts in the solenoid switch are closed to connect the battery directly to the starter. Closing of the main switch contacts shorts out the pull-in winding since this winding is connected across the main contacts. The magnetism produced by the hold-in winding is sufficient to hold the plunger in, and shorting out the pull-in winding reduces drain on the battery. When the control switch is opened momentarily, the pull-in winding and the hold-in winding are connected in series between the battery and common ground.
The polarity of the pull-in winding is reversed and opposes the magnetic pull of the hold-in winding. The magnetic holding force on the solenoid plunger is thus canceled. The return spring then quickly pulls the solenoid plunger back, opening the solenoid switch contacts and withdrawing the pinion gear from the meshing position at the same time. Proper operation of the switch depends on maintaining a definite balance between the magnetic strength of the pull-in and hold-in windings.
This balance is established in the design by the size of wire and the number of turns specified.
An open circuit in the hold-in winding or attempts to start the motor with a discharged battery may cause the switch to chatter.
11.5.1 Disassembly
To disassemble the solenoid, remove nuts, washers, and insulators from the switch terminal and battery terminal. Remove the cover screws and cover. Take out the contact disk assembly.
11.5.2 Solenoid Maintenance
The solenoid requires no periodic maintenance other than keeping the terminals clean and tight.
Always check the action of the solenoid if it has been removed. If the unit fails to function, first check wiring before condemning the solenoid.
Solenoid windings can be checked for open or short circuit or current draw.
06085 11.5.3 Solenoid Tests
Two tests must be made to determine the current draw of (1) both windings in parallel and
(2) the hold-in winding alone. The solenoid
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Section 6: ELECTRICAL windings can be tested with the solenoid either off or on the starter. However, when the solenoid is checked on the starter, it is necessary to disconnect both leads at the main solenoid terminals to prevent interference. The main solenoid terminal that is normally connected to the starter must then be grounded to the solenoid base by means of a jumper lead.
For the first test, connect a source of variable voltage (battery and a variable resistance) in series with an ammeter between the solenoid base and the solenoid small switch terminal.
Connect a voltmeter between the same two points. Slowly increase voltage and note the current draw. It should be 55-63 amps at 24 volts. Disconnect the jumper lead grounding the main solenoid terminal and readjust the variable resistance to obtain the specified voltage of 24 volts. It should not exceed 6.8 amperes.
When the solenoid has been removed from the starter for repair or replacement, the linkage must be adjusted to provide the correct pinion clearance when the solenoid is remounted on the starter. See “Pinion Clearance” earlier in this section for correct pinion clearance adjustment.
11.5.4 Recommendations
1. Tag each lead to ensure correct connections when the starter is reinstalled.
2. Tighten the 5/8”-11 starter attaching bolts to a torque of 137-147 ft•lbf (186-200 N•m).
3. Keep all the electrical connections clean and tight.
4. When installing wiring terminal leads to the starter and the solenoid switch, torque the
No. 10-32 connections to 16-30 in•lbf (2-3
N•m) and the ½”-13 connections to 18-20 ft•lbf (24-27 N•m). For first nut and 24-27 ft•lbf (33-36 N•m) for the terminal one.
12. ENGINE BLOCK HEATER
The vehicle may be equipped with an engine immersion-type electric block heater to assist cold weather starting. The heater male electric plug is easily accessible through the engine compartment R.H. side door (Fig. 51). To use it, connect the female plug of an electrical extension cord to the heater plug. The extension cord must be plugged into a 110-120 V AC power source only. The engine block heater should be used whenever the vehicle is parked for an extended period of time in cold weather and a suitable power source is available.
FIGURE 51: ELECTRIC HEATER PLUG LOCATION 18354
12.1 MAINTENANCE
This heater is non-serviceable except for the cord, and if faulty, must be replaced as a unit.
13. EXTERIOR LIGHTING
The circuit for exterior lights, as well as their control switches, relays and circuit breakers are shown on the applicable wiring diagrams. Wiring diagrams are located in the technical publication box.
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13.1 HEADLIGHTS
Each headlight assembly consists of a 12 volt halogen rectangular lamp unit and a front turn signal light. Headlight lamps are double-filament units, having high and low beams.
13.1.1 Headlight Beam Toggle Switch
The multifunction lever located on the steering column is used to select proper lighting. High beams or low beams can be selected by pulling the lever rearward. A high beam indicator on the central dashboard panel is illuminated when the high beam circuit is energized.
Note: Pulling the lever rearward while the lights are off will flash the headlights.
13.1.2 Maintenance
Clean headlights with soap and water and a good glass cleaner whenever dirty. For maximum illumination, headlight connections must be coated with a dielectric grease to prevent oxidation and proper voltage must be maintained. Low battery voltage, loose or dirty contacts in wiring system and poor ground contribute to a decrease in voltage. Check wiring and connections regularly and keep battery properly charged. When a headlight burns out, a new bulb must be installed.
Headlight aiming is not necessary after a bulb replacement.
Headlights must be properly aimed to provide maximum allowable road illumination. When using mechanical aiming devices, follow manufacturer’s instructions.
Headlight aim should be checked after installing a new headlight unit. Aiming can be performed without removing headlight assembly. Horizontal and vertical aiming of each headlight unit is provided by two adjusting screws that move the headlight unit within its support (fig. 58). There is no adjustment for focus since the headlight unit is set for proper focus during manufacturing assembly.
Section 6: ELECTRICAL
13.1.3 Headlight Adjustment
The following is a general procedure for headlight adjustment using a mechanical equipment, such as a “Bear 47-132 headlight aligner”. If your mechanical equipment is different, refer to the manufacturer’s instruction manual.
Setting aligner according to slope
The floor level offset dial must match with slope to ensure a precise alignment.
1. Park vehicle on a level floor.
2. Fix one (1) calibration fixture to each aligner.
3. Install aligner in center of each wheel on one side of vehicle. Unit B must be installed beside the front axle wheel with its viewing port facing rearward, and unit A beside the drive axle wheel with its viewing port facing forward. See figure 54 for more details.
Note: Check that the three indicators on each module are set to zero.
4. Level each unit with the thumb adjusting screw on the fixture until level-vial bubble is centered.
5. Look through the top port hole of unit A, and turn horizontal knob until split images are aligned. See figure 53.
FIGURE 53: HEADLIGHT ALIGNMENT
06088
6. Set according to floor slope. Transfer positive (+) or negative (-) reading of horizontal dial to the floor level offset dial to offset floor slope on each aligner (Fig. 55).
Push on the floor level offset dial to register reading.
7. Remove calibration fixture from each unit.
Note: If vehicle remains stationary during the headlight alignment procedure, it is not necessary to check floor slope each time.
FIGURE 52: HEADLIGHT ASSEMBLY
06405
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Section 6: ELECTRICAL
06087
FIGURE 55: HEADLIGHT ALIGNER
06089
Headlight Alignment
The aligner is provided with adapters for different sizes of headlights that are always aligned in pairs.
1. Fix the adequate adapter on each headlight.
Note: The adapters are equipped with steel inserts, thus providing a good seating for precise headlight adjustment.
2. Install aligners on headlights (unit A on driver’s side and unit B on other side with the sight openings facing each other) by pushing the handle forward to secure rubber suction disc. Pull handle until it locks. Refer to figure 56.
FIGURE 56: HEADLIGHT ALIGNMENT
06090
Note: Ensure that floor level offset dial is set correctly before aligning headlights.
Horizontal Alignment
1. Reset horizontal dial to zero.
2. Check that split image is visible in the viewing port. If not, reposition aligner by turning it.
3. Turn the horizontal aim adjusting screw of each headlight until split image is aligned
(Fig. 57 and 58).
FIGURE 57: HEADLIGHT ALIGNMENT 06091
06-46
Vertical Alignment
1. Reset vertical dial to zero.
2. Turn the adjusting screw of the headlight vertical aim until bubble is centered (Fig. 57 and 58). Repeat operation on other headlight.
3. Recheck the horizontal alignment.
Remove aligners by pressing on vacuum release button.
Repeat the same procedure for the high beams.
Section 6: ELECTRICAL
13.1.4 Headlight Unit Replacement
Removal
1. Remove screw fixing headlight assembly to its housing (Fig. 52) and pivot assembly out.
2. Remove socket from headlight lamp connector.
3. Remove six mounting screws attaching headlight unit to support.
FIGURE 58: ALIGNMENT SCREWS
06413
If proper mechanical equipment is not available, perform adjustments as described below:
1. Park vehicle on level floor so headlights are
25 feet (7,6 m) from a smooth surface preferably of light color. A door or wall is suitable. Centerline of vehicle should be perpendicular to this vertical surface.
2. Draw a horizontal line on vertical surface at height of light center. Locate point on this horizontal line at which projected centerline of vehicle intersects. Measure distance between light centers and divide this distance equally on either side of center mark. Then draw two vertical lines directly ahead of each light center.
3. Switch on high beams and cover one headlight while adjusting the other.
4. When aiming headlights, beam may appear distorted. A new headlight unit must be installed to correct this condition.
5. After headlight is properly aligned, cover it and proceed in the same manner as above with opposite headlight.
FIGURE 59: TOP VIEW OF HEADLIGHT ASSEMBLY 06421
Installation
1. Install wiring connector on back of new headlight unit. Position unit in support with molded lens number at top.
2. Secure headlight unit using six mounting screws.
3. Pivot headlight assembly back into its housing then secure using fixing screw.
4. Perform alignment procedure.
Note: The headlight aim must be checked and adjusted even if it was properly adjusted before the headlight unit was replaced.
13.1.5 Headlight Bulb Removal and
Replacement
1. Remove the headlight screw fixing the headlight assembly, then pivot headlight assembly out.
2. Remove socket from headlight lamp.
3. Remove the bulb by pushing and rotating it out of the socket.
4. Install the new bulb by reversing the previous procedure.
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Section 6: ELECTRICAL
13.2 FRONT TURN SIGNAL
The front turn signal is part of the headlight assembly. The turn signal lens is located on each front corner and shares a common support with the headlights. Turn signal is visible from both front and side.
13.2.1 Front Turn Signal Light Replacement
Removal
1. Remove screw fixing headlight assembly to its housing (Fig. 52) and pivot assembly out.
2. Remove socket from front turn signal light lamp connector.
3. Remove four mounting screws attaching front turn signal light to support.
Installation
1. Install wiring connector on back of new front turn signal light. Position unit in support with molded lens number at top.
2. Secure front turn signal light using four mounting screws.
3. Pivot headlight assembly back into its housing then secure using fixing screw.
13.2.2 Front Turn Signal Light Bulb Removal and Replacement
1. Remove the headlight screw fixing the headlight assembly, then pivot headlight assembly out.
2. Remove socket from front turn signal light.
3. Remove the bulb by pushing and rotating it out of the socket.
4. Install the new bulb by reversing the previous procedure.
13.3 STOP, TAIL, DIRECTIONAL, BACK-UP,
AND HAZARD WARNING LIGHTS
A combination stoplight, taillight, directional signal light and back-up light assembly is mounted at the rear, on each side of the vehicle.
Furthermore, when braking, two center stoplights (LED) and a cyclops light (LED) will illuminate simultaneously with the stoplights on the sides for increased safety. The L.H. and
R.H. side center stop lights are also used as directional signal and marker lights.
The stop, tail, directional signal and back-up lights consist of individual bulbs mounted in a common housing, and each light is serviced individually as a complete unit and need only to be plugged into or unplugged from socket after removing proper light lens.
The hazard warning flashing system uses the front, side and rear directional lights simultaneously. This system is energized by a switch on the L.H. dashboard.
13.3.1 Bulb Removal and Replacement
1. Unscrew the retaining lens screws (2), then remove the lens.
2. Remove the bulb by pushing and then rotating it counterclockwise out of the socket.
3. Install the new bulb by pushing and rotating it clockwise, then replace the lens; the
“Hella” inscription molded on the lens must be pointing upwards.
Note: Lens must be installed in their original position.
Note: Taillights are provided with a different candle power bulb. Make sure appropriate replacements are used for any defective bulbs.
13.4 LICENSE PLATE LIGHT
Two sealed units are mounted above the rear license plate(s) of vehicle. In case of burn out, the sealed unit must be changed according to the following procedure.
1. Pry out the rubber seal with a small screwdriver. Pull on the sealed unit and disconnect it.
2. Reconnect new sealed unit, place rubber seal, and press on it until it is seated in position.
13.5 CLEARANCE, IDENTIFICATION AND
MARKER LIGHTS
The vehicle is equipped with marker, identification and clearance lights (LED). The clearance lights are mounted at each corner of the coach near the top and the identification lights are in the upper center of rear and front sections. The rear clearance lights are red and the front ones are amber.
The amber marker lights are mounted along the sides of vehicle.
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Section 6: ELECTRICAL
VARIOUS LOCATION
06412
13.5.1 Marker Light Removal and Replacement
The side marker light is a sealed unit (LED) and should be replaced as an assembly in accordance with the following procedure:
1. Unscrew both light screws, then remove the light assembly.
2. Position the new light assembly and install the “Phillips” screws.
13.5.2 Clearance and Identification Light
Removal and Replacement
The clearance and identification light are sealed units (LED) and can be replaced in accordance with the following procedure:
1. Unscrew both “Phillips” light screws, then remove the light assembly.
2. Position the new light assembly, then install the “Phillips” screws.
13.6 DOCKING AND CORNERING LIGHTS
MTH vehicles are provided with two halogen headlights that serve as cornering lights. They are mounted on the vehicle as follows: one is mounted on the front L.H. side service compartment door, while the other is located on the entrance door on the R.H. side. The main function of these lights is to increase lateral visibility when turning a corner. These lights are energized simultaneously with the directional lights. A dashboard-mounted rocker switch may be actuated to cancel this system in special situations.
Two additional halogen headlights are installed aft of the rear baggage compartment. These lights are used as docking lights and both will illuminate automatically when reverse range is selected to facilitate back-up or docking procedure. These lights do not operate automatically when the reverse range is selected, but by means of a dashboard-mounted rocker switch. When actuated, the docking as well as the cornering lights illuminate.
13.6.1 Lamp Removal and Replacement
Both docking and cornering headlights can be changed in accordance with the following procedure:
1. Remove the two “Phillips” screws attaching the retaining ring.
2. Disconnect the light unit connection.
3. Remove the lamp.
4. Position new lamp.
5. Connect and position the light unit.
6. Finally, install the retaining ring.
Standard halogen fog lights (MTH) or optional
(coaches), can be mounted on this vehicle to give the driver better visibility in foggy weather,
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Section 6: ELECTRICAL or to improve the range of vision just ahead of the coach.
13.7.1 Bulb Removal and Replacement
1. Remove the protector cap on light unit (if so equipped). Remove the light unit retainer screw and slide the retainer upward.
2. Remove the light unit. Disconnect the light unit connection.
3. Remove retaining clip from its notches, then lift the retaining clip and remove the bulb.
4. Install the new bulb, then replace the retaining tab of clip to its position into the notches.
Caution: During this step, avoid contacting the bulb with your fingers. This could alter the bulb life.
5. Reconnect the light unit and replace in its proper position.
6. Replace the retainer.
7. Replace the light unit cover (if so equipped).
14. INTERIOR LIGHTING EQUIPEMENT
14.1 CONTROL PANEL LIGHTING
The instrument gauges and switches mounted on all control panels are energized whenever the exterior light switch is pushed to the first position. A control dimmer located on the dashboard is used to vary the brightness of the panel gauges, switches and indicator lights.
The gauge lights, panel lights, switch lights and indicator lights have a different bulb arrangement. Thus, the procedure to change a defective bulb can vary according to the application.
14.1.1 Switch Lighting
1. Slightly pull the switch with a defective LED away from the control panel.
2. Disconnect the electric cable from the switch.
3. To install a new switch, reverse the procedure (Fig. 60).
Note: Switches are lighted by the use of LED.
When lighting on a switch fails, replace defective switch as a unit.
06-50
FIGURE 61: SWITCH 06321
14.1.2 Telltale Light Replacement
Telltale module is non-serviceable and must be replaced as a unit.
1. Unscrew and remove the top dashboard panel.
2. Remove the telltale back wire electric connectors.
3. Unscrew and remove the telltale module.
4. To replace the telltale module, reverse the procedure.
14.1.3 Gauge Light Bulb Replacement
1. For any gauge light bulb replacement, the dashboard panel must be removed in order to have access to the rear of gauges.
2. Remove bulb socket from the gauge, turn the defective bulb counterclockwise and pull it out of the gauge.
3. Push a new bulb and socket ASM and turn clockwise to lock in place.
4. Replace the rear dashboard housing.
14.2 STEPWELL LIGHTS AND LAVATORY
NIGHT-LIGHT
Stepwell lights are illuminated when the door opening system is activated.
The lavatory night-light is illuminated as soon as the ignition switch is set to the “ON” position.
14.2.1 Bulb Removal and Replacement
Proceed as follows to replace defective bulb:
1. Unscrew the two Phillips-head screws retaining the lens to the lavatory wall, and remove it.
2. With the light lens removed, pull bulb from the lamp while applying lateral pressure.
3. Install the new bulb into the lamp.
4. Position the light lens and install it.
14.3 DRIVER’S AREA LIGHTS
Two halogen ceiling lights are installed over the stepwell and the driver’s area. These lights are frequently used for night-time operation when passengers board or leave coach.
14.3.1 Bulb Removal and Replacement
1. Unsnap the lamp with a flat head screwdriver and remove it.
2. Pull the defective bulb out of the socket.
3. Install the new bulb by pushing it in position.
4. Replace the lamp by snapping it back in place.
Caution: Do not touch halogen bulbs with bare hands as natural oils on skin will shorten bulb life span.
Section 6: ELECTRICAL
14.4 PASSENGER SECTION LIGHTING
The passenger section of coach is lit by two types of fluorescent tube lamps installed on the parcel racks.
The aisle lights are located on front of parcel racks, and provide soft, indirect cabin lighting and parcel rack interior lighting. More powerful lighting for general and in-station applications is provided by fluorescent tubes located under the parcel racks, close to the windows. A dual power system is available for this lighting either from the 24 volt vehicle power supply or from a
110 volt outlet supply. In order to save batteries during extended periods of in-station lighting, no current is drawn from the batteries as soon as the 110 volt circuit is connected.
Moreover, adjustable reading lamps are installed under the parcel racks for passenger accommodation.
FIGURE 62: PARCEL RACK LIGHTING 06419
14.4.1 Fluorescent Tube Replacement
Indirect Fluorescent Light
1. Open the parcel rack access door, if so equipped, unscrew the two Phillips screws
(one each end). Let the hinged cover down.
2. Remove fluorescent tube from light socket.
3. Install a new fluorescent tube.
4. Lift the hinged cover and replace the two retaining screws (Fig. 61).
Parcel Rack Interior Lighting
1. Open the parcel rack access door, if so equipped, unscrew the two Phillips screws
(one each end). Pull the hinged cover down.
2. Push on the bulb, turn and then, pull it from the socket.
3. Install a new bulb.
06- 51
Section 6: ELECTRICAL
4. Lift the hinged cover and replace the two retaining screws.
14.4.2 Removal and Replacement of In-Station
Fluorescent Tubes
1. Start by pulling out the corner of the lens then delicately peeling it out of its seat.
Caution: The lens is fragile. Be very careful when removing and handling.
2. Rotate and pull the fluorescent tube from its sockets.
3. Install a new fluorescent tube, rotating the tube to secure it in the sockets.
4. Replace the screen lens by first inserting one side in the seat, then push the other side in and snap it in place by running it in from one corner to the next.
14.4.3 Removal and Replacement of Reading
Lamp Bulb
1. Engage the tool (#830164) over the lamp and turn one quarter turn counterclockwise.
Then, remove the tool slowly.
2. Pull the bulb socket off the reading lamp unit.
3. Push and turn bulb counterclockwise, then pull it out of the socket.
4. Install new bulb in the socket, then push and turn clockwise to lock bulb in position.
5. Push the bulb socket in the reading lamp unit.
6. Position the reading lamp with the tool
(#830164), turn one quarter turn clockwise.
14.5 ENGINE COMPARTMENT LIGHTING
A switch located on R.H. side of rear junction box can be used to actuate the two circular engine compartment lights.
Each light is provided with one bulb that can be replaced as follows:
1. Remove the lens by unscrewing the ring two fixing screws, pry out the lens.
2. Push and turn the defective bulb counterclockwise, then pull it out of the socket.
3. Install the new bulb in the socket, then push and turn clockwise to lock bulb in position.
4. Install the lens, and fasten the ring two fixing screws.
FIGURE 63: ENGINE COMPARTMENT LIGHT
06425
The lavatory light is installed on ceiling and is provided with two bulbs. A microswitch, mounted in the door exterior frame, is activated by the door lock mechanism upon locking to energize the circuit. This switch is readily serviced by removing the two Phillips-head screws securing the mounting plate to the door exterior frame.
Proceed as follows to replace a bulb:
1. Remove the lens by the use of a flat screwdriver to pry the lens out.
Push and turn the defective bulb counterclockwise, then pull it out of the socket.
3. Place the new bulb into the socket, then push and turn clockwise to lock bulb in position.
4. Place the lens, and snap it in place.
15. LIGHT BULB DATA
When replacing a light bulb, special attention must be paid to the voltage rating (refer to light bulb date hereafter).
Note : All exterior lights are 12 volts and all interior lights are 24 volts, except for the “Check engine” and “Stop engine” warning lights and flasher indicator lights which are also on 12 volt system.
06-52
Section 6: ELECTRICAL
LIGHT BULB DATA
APPLICATION PREVOST
PART NO.
TRADE OR
SAE
NUMBER
WATTS OR
CANDLE
POWER
VOLTS QTY
EXTERIOR LIGHTING
Docking & cornering
Fog
License plate (sealed)
Marker Light (red)
Marker Light (amber)
Identification (red)
Clearance (red)
Identification (amber)
Clearance (amber)
Front directional
(hazard & marker)
Rear directional
930319
561882
930266
930340
930341
930334
930334
930337
930337
9004 W
9415
H3 (OSRAM)
TL 15206
Grote 47072-3
Grote 47073
TL 25420R
TL 25420R
TL 25450Y
TL 25450Y
37.5W
55 W
---
---
---
---
---
---
---
12
12
12
12
12
12
12
12
12
4
2
2
2
10
3
4
3
4
562135 3057 32/3W 12 2
560589 1156 32 W 12 4
Center stop 930330 HELLA 96208 --- 12 2
Exterior compartment
(except engine)
Engine compartment
INTERIOR LIGHTING
Instrument cluster lights
Telltale panel assy.
Step light
562278
560136
562838
562791
562278
HELLA 78207
OSRAM 6429
1003
2721 MFX
(OSRAM)
---
HELLA 78207
OSRAM 6429
10 W
15cp
---
10 W
24
12
---
24
12
2
1
3
06- 53
Section 6: ELECTRICAL
16. SPECIFICATIONS
Battery
Make............................................................................................................................................ Delco-Remy
Model....................................................................................................................................................... 1150
Type ....................................................................................................................................Maintenance-free
Terminal type ................................................................................................................................... Top Stud
Group size................................................................................................................................................... 31
Volts ............................................................................................................................................................ 12
Load test amperage .................................................................................................................................. 290
Reserve capacity (minutes) ...................................................................................................................... 180
Cold cranking (in amps)
-At 0 o F (-18
-At-20 o o
F (-29
C)....................................................................................................................625 (each battery) o
C) .................................................................................................................490 (each battery)
Maximum dimensions (inches/mm)
-Length (including flange) .............................................................................................................. 13.0/330,2
-Width ............................................................................................................................................... 6.8/172,7
-Height (including top posts) ............................................................................................................ 9.4/238,8
-Approximate weight (lbs/kg) .............................................................................................................. 60/27,2
Battery tester cable clamps should be between terminal nuts and lead pads of terminals. If not possible, load value should be 210 amperes.
Torque specifications
Battery cable to post ..................................................................................................10-15 ft-lbf (13-20 N
· m)
Battery cover ..................................................................................................................45-50 ft-lbf (5-6 N
· m)
Electrical system monitor
Make.................................................................................................................................................... Vanner
Model.................................................................................................................................................... EM-70
Input ....................................................................................................................................................24 V dc
System high .................................................................................................................. Greater than 30 V dc
System low......................................................................................................................... Less than 24 V dc
Trip level........................................................................................................................................+ 0.75 V dc
Prévost Number .................................................................................................................................. 562058
Alternator
Make............................................................................................................................................ Delco Remy
Model Number................................................................................................................................... 1117702
Series .....................................................................................................................................................50DN
Type .......................................................................................................................................................... 600
Field current at 80 o
F (27 o
C)
-Amperes........................................................................................................................................... 7.2 – 8.0
-Volts ........................................................................................................................................................... 24
Hot output
-Amperes............................................................................................................. 270 at 80 o
F (27 o
C) ambient
-Volts ........................................................................................................................................................... 28
-Approximate rpm.................................................................................................................................... 3000
Ground .............................................................................................................................................. negative
Prévost number................................................................................................................................... 561723
Alternator
06-54
Section 6: ELECTRICAL
Make................................................................................................................................................... BOSCH
Model Number............................................................................................................................. 0120689552
Series .......................................................................................................................................................... T1
Hot output
-Amperes.................................................................................................................. 140 at 25°C (AMBIENT)
-Volts ........................................................................................................................................................... 28
-Approximate rpm.................................................................................................................................... 6000
Ground .............................................................................................................................................. negative
Prevost Number .................................................................................................................................. 562752
Regulator
Make............................................................................................................................................ Delco-Remy
Model Number.................................................................................................................................................
Type ................................................................................................................................................ Transistor
Voltage adjustment ................................................................................................................. External screw
Prévost number 562775
Battery equalizer
Make.................................................................................................................................................... Vanner
Model................................................................................................................................................... 60-50A
Amperes............................................................................................................................................ 50 amps
Prévost Number .................................................................................................................................. 561016
Battery equalizer
Make.................................................................................................................................................... Vanner
Model....................................................................................................................................................60-100
Amperes.......................................................................................................................................... 100 amps
Prévost Number .................................................................................................................................. 562970
Starter
Make............................................................................................................................................ Delco-Remy
Model Number................................................................................................................................... 1990269
Series ....................................................................................................................................................50 MT
Type .......................................................................................................................................................... 400
Rotation (viewing drive end) ..................................................................................................................... CW
Brush tension ..................................................................................................................... 5 lbs (2,2 kg) Min.
Voltage ........................................................................................................................................................ 24
No-load test
-Volts ........................................................................................................................................................... 23
-Min. current draw ........................................................................................................................ 60 amperes
-Max. current draw ....................................................................................................................... 90 amperes
-Min. rpm ..........................................................................................................................................7000 rpm
Starter solenoid
Make............................................................................................................................................ Delco-Remy
Model Number................................................................................................................................... 1115557
Current Draw 80 o
F(27 o
C)
-Hold-in winding .................................................................................................................... 7.35 – 8.2 amps
-Pull-in winding....................................................................................................................... 48 – 54.5 amps
Volts ............................................................................................................................................................ 24
06- 55
Repair and Testing Instructions for T1 Page 1
Alternator 0120 689 552 Edition 001
Repair and Testing
Instructions for
T1 Alternator
0120 689 552
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T1ALTFinal.DOC
Repair and Testing Instructions for T1 Page 2
Alternator 0120 689 552 Edition 001
Modifications
Edition
001
002
Date
8/28/98
12/4/98
Name
I. Serra
I. Serra
Modifications
Original
Update 8.98 Instructions
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Repair and Testing Instructions for T1 Page 3
Alternator 0120 689 552 Edition 001
Table of contents
1 GENERAL ............................................................................................................................................................... 5
2 SAFETY PRECAUTIONS....................................................................................................................................... 6
2.1
S PECIAL T OOL U SAGE .......................................................................................................................................... 6
2.2
F IRE R ISK ............................................................................................................................................................ 6
2.3
S KIN P ROTECTION ............................................................................................................................................... 6
2.4
C OMPRESSED A IR ................................................................................................................................................ 6
2.5
E XPLOSION R ISK .................................................................................................................................................. 6
3 SPECIFICATIONS .................................................................................................................................................. 7
3.1
E LECTRICAL T EST S PECIFICATIONS ...................................................................................................................... 7
3.2
M ECHANICAL T EST S PECIFICATIONS ..................................................................................................................... 8
3.3
T IGHTENING T ORQUES ......................................................................................................................................... 8
4 ALTERNATOR SCHEMATIC ............................................................................................................................... 9
5 ALTERNATOR CODING..................................................................................................................................... 10
6 PARTS CLEANING .............................................................................................................................................. 11
7 TOOLS, TEST EQUIPMENT LUBRICANTS AND ADHESIVES..................................................................... 12
7.1
T EST E QUIPMENT .............................................................................................................................................. 12
7.2
S PECIAL T OOLS ................................................................................................................................................. 12
7.3
L UBRICANTS AND A DHESIVES ............................................................................................................................ 13
7.3.1
Lubricant Quantities ................................................................................................................................. 13
8 EXPLODED VIEW................................................................................................................................................ 14
9 ALTERNATOR DISASSEMBLY AND TESTING .............................................................................................. 15
9.1
R EAR C OVER R EMOVAL ..................................................................................................................................... 15
9.2
V OLTAGE R EGULATOR R EMOVAL ....................................................................................................................... 15
9.2.1
Brush Replacement ................................................................................................................................... 16
9.3
N OISE S UPPRESSION C APACITOR T ESTING AND R EMOVAL .................................................................................... 16
9.4
P ULLEY AND F AN R EMOVAL ............................................................................................................................... 17
9.5
S EPARATION OF D RIVE S HIELD AND C OLLECTOR E ND S HIELD ............................................................................. 17
9.6
R ECTIFIER A SSEMBLY T ESTING .......................................................................................................................... 18
9.7
R EMOVAL AND T ESTING OF S TATOR A SSEMBLY .................................................................................................. 19
9.8
R ECTIFIER A SSEMBLY R EMOVAL ........................................................................................................................ 20
9.9
D AMPENING R ESISTOR T ESTING AND R EMOVAL .................................................................................................. 21
9.10
R EMOVAL OF C OLLECTOR E ND S HIELD B EARING AND S EAL ................................................................................. 21
9.11
R EMOVAL OF S LIDING B USHING IN C OLLECTOR E ND S HIELD ............................................................................... 22
9.12
R EMOVAL OF R OTOR FROM D RIVE E ND S HIELD ................................................................................................... 22
9.13
R EMOVAL OF B EARING AND S EAL FROM D RIVE E ND S HIELD ................................................................................ 24
9.14
R EMOVAL OF C OLLECTOR R ING E ND I NNER B EARING R ACE FROM R OTOR ............................................................ 24
9.15
R OTOR I NSPECTION ........................................................................................................................................... 25
9.16
C OLLECTOR R ING R EPLACEMENT ....................................................................................................................... 26
10 ALTERNATOR ASSEMBLY............................................................................................................................ 27
10.1
R OTOR A SSEMBLY ............................................................................................................................................. 27
10.2
D RIVE E ND S HIELD A SSEMBLY ........................................................................................................................... 28
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Repair and Testing Instructions for T1 Page 4
Alternator 0120 689 552 Edition 001
11
10.3
C OLLECTOR R ING E ND S HIELD A SSEMBLY ......................................................................................................... 29
10.4
R ECTIFIER A SSEMBLY ........................................................................................................................................ 30
10.5
S TATOR A SSEMBLY ........................................................................................................................................... 32
10.6
R OTOR AND D RIVE E ND S HIELD I NSTALLATION .................................................................................................. 32
10.7
R EGULATOR AND C APACITOR I NSTALLATION ...................................................................................................... 33
FUNCTIONAL TESTING ................................................................................................................................. 35
11.1
G ENERAL I NFORMATION .................................................................................................................................... 35
11.1.1
Power Output Tests ................................................................................................................................... 35
11.1.2
Voltage Trace Evaluation ......................................................................................................................... 35
11.2
P OWER O UTPUT T ESTING ................................................................................................................................... 35
11.2.1
Test Bench Mounting ................................................................................................................................ 35
11.2.2
Power Output Test .................................................................................................................................... 36
11.3
V OLTAGE T RACE E VALUATION .......................................................................................................................... 37
11.3.1
Oscilloscope Hook-up ............................................................................................................................... 37
11.3.2
Normal Pattern ......................................................................................................................................... 38
11.3.3
Open Exciter Diode .................................................................................................................................. 39
11.3.4
Open Positive Rectifier Diode................................................................................................................... 40
11.3.5
Open Negative Rectifier Diode ................................................................................................................. 41
11.3.6
Shorted Exciter Diode............................................................................................................................... 42
11.3.7
Shorted Positive Rectifier Diode ............................................................................................................... 43
11.3.8
Shorted Negative Rectifier Diode.............................................................................................................. 44
11.3.9
Open Phase of Stator ................................................................................................................................ 45
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Repair and Testing Instructions for T1 Page 5
Alternator 0120 689 552 Edition 001
1 General
This manual contains repair and testing instructions with corresponding test specifications for the 0 120 689 5...
series alternators.
T1 (RL) 28V 70/140A
Note: Alternator 0 120 689 543 was utilized in preparing these instructions.
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Repair and Testing Instructions for T1 Page 6
Alternator 0120 689 552 Edition 001
2 Safety Precautions
2.1 Special Tool Usage
The use of incorrect or unsuitable tools and test equipment can lead to personal injury and may damage the alternator or its component parts. Only use tools that are specified in this instruction or meet the specification of the recommended tools.
2.2 Fire Risk
To provide radio interference suppression, the alternator is equipped with capacitors with a long storage time. Cleaning of alternator components may cause and electrical discharge when they are immersed in cleaning fluid. This discharge may cause combustible liquids to ignite.
2.3 Skin Protection
To avoid skin irritation when handling oils and greases, apply protective gloves or creams before starting work and wash off hands with soap and water when servicing has been completed.
2.4 Compressed Air
Only use compressed air regulated to a maximum of 4 Bar (60 PSI), and a clean cloth for cleaning of the armature, excitation windings and alternator plates.
2.5 Explosion Risk
Avoid exposure to fire, open flame and sparks. Thoroughly dry all cleaned parts as gases could form from the cleaning process and may cause an explosion.
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Repair and Testing Instructions for T1 Page 7
Alternator 0120 689 552 Edition 001
3 Specifications
3.1 Electrical Test Specifications
Interference suppression capacitor 1.8 … 2.6 l F (microfarad)
Load current less than/equal to 10A
Damping Resistance
Stator Resistance
27.6 … 28.4 V (volts, regulated)
3.1 … 3.5 k W (kilohms)
0.036 W (-0/+10%) T1 (RL) 28V70/140A
7.5 W (-0/+10%) T1 (RL) 28V70/140A Rotor Resistance
Power Output Test
Alternator
T1 (RL) 28V70/140 A
Speed (RPM) Load Current -
Inductive (A)
1500
6000
76
136
Test Duration
(Min)
30
10
Following completion of the output test, allow alternator to run at 7000 rpm for one minute.
Oscilloscope Pattern
This image represents a properly functioning alternator. The D.C. voltage produced has a small harmonic wave.
Small spikes may be superimposed on the oscilloscope screen if the voltage regulator is regulating. Applying a load to the alternator output terminals can turn off the regulator.
In order to be able to compare oscilloscope images, the oscilloscope so the pattern fits between two vertical 10x divisions.
Figure 1 Normal Oscilloscope Pattern
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Repair and Testing Instructions for T1 Page 8
Alternator 0120 689 552 Edition 001
3.2 Mechanical Test Specifications
Rotor to Stator Air Gap (Between any side of stator and rotor)
Collector ring diameter New
Used
Greater than 0.3 mm (0.012 in)
Eccentricity (Rotor mounted at bearing points)
Outer Diameter Of Rotor 0.05 mm (0.002 in) maximum
Outer Diameter Of Collector Rings 0.03 mm (0.0012 in) maximum
32.5 mm (1.279 in)
31.5 mm (1.240 in) minimum
16.0 mm (0.630 in) minimum
7.0 mm (0.275 in) minimum
Carbon Brush Projection New
Used
3.3 Tightening Torques
Item Number Description
55 Air Intake Stud
66
29
D+ Terminal
B+ Terminal, B- Terminal
37
15
43
23
W Terminal
Voltage Regulator
Capacitor Mounting Screw
Rectifier Mounting Screw
21
5
52
Drive End Shield to Collector Ring Shield
Drive End Shield Bearing Cover Plate
Pulley Retaining Nut
Metric (Nm)
3.0 … 3.4
2.4 … 3.2
10.0 … 13.0
4.1 … 5.5
1.3 … 1.7
4.3 … 5.7
1.3 … 1.7
7.2 … 9.7
4.1 … 5.5
135 … 170
SAE
26.5 … 30.1 in. lbs.
21.2 … 28.3 in. lbs.
88.5 … 115 in. lbs.
36.3 … 48.7 in. lbs.
11.5 … 15.0 in. lbs.
38.0 … 50.4 in. lbs.
11.5 … 15.0 in. lbs.
63.7 … 85.9 in. lbs.
36.3 … 48.7 in. lbs.
99.5 … 125.4 ft. lbs.
UA/ASV
Figure 2 Fastener Torque Chart
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Repair and Testing Instructions for T1 Page 9
Alternator 0120 689 552 Edition 001
4 Alternator Schematic
Figure 3 Alternator/Voltage Regulator Schematic
1 Alternator
B+ Battery Positive
BBattery Negative
D+ Dynamo + (Warning Lamp Output)
W Tachometer Output
2 Voltage Regulator
D+ Dynamo + (Alternator Output)
DF Dynamo Field
DDynamo -
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Repair and Testing Instructions for T1 Page 10
Alternator 0120 689 552 Edition 001
5 Alternator Coding
T 1 R 28V 70/ 140A
Rated current in amps measured at 6000 rpm
Rated current in amps measured at 1500 rpm
Alternator Voltage
Direction of Rotation
(
→
) Or R Clockwise
(
←
) Or L
(
↔
) Or RL
Counter Clockwise
Multidirectional
1 Claw Pole Alternator
2 Salient Pole Alternator
3 Windingless Rotor Alternator
Outer Diameter of Alternator
G
K
N
T
U
100 … 109 mm
120 … 129 mm
130 … 139 mm
170 … 199 mm more than 200 mm
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Repair and Testing Instructions for T1 Page 11
Alternator 0120 689 552 Edition 001
6 Parts Cleaning
Caution: Fire Risk
To provide radio interference suppression, the alternator is equipped with capacitors with a long storage time.
Cleaning of alternator components may cause and electrical discharge when they are immersed in cleaning fluid. This discharge may cause combustible liquids to ignite.
Alternator components with capacitors should only be cleaned with a non-combustible cleaner such as HAKU
1025/6.
Caution: Compressed Air
Only use compressed air regulated to a maximum of 4 Bar (60 PSI), and a clean cloth for cleaning of the armature, excitation windings and alternator plates.
Caution: Explosion Risk
Avoid exposure to fire, open flame and sparks. Thoroughly dry all cleaned parts as gases could form from the cleaning process and may cause an explosion.
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Repair and Testing Instructions for T1 Page 12
Alternator 0120 689 552 Edition 001
7 Tools, Test Equipment Lubricants and Adhesives
7.1 Test Equipment
Description
Alternator Test Bench
Internal Short-Circuit Tester (Flash Tester)
Universal Multi-Meter
Alternator Tester
7.2 Special Tools
Description
Arbor Press
Soldering Iron
Universal Bearing Puller
V-Block
Note: 2 Required
14mm Hex, 1/2" Drive Socket
Clamping Support
Die Spigot for Arbor Press (Used with KDLJ 6011, KDLJ 6012,
KDLJ 6015)
Bearing Remover
Press Tool for Roller Bearing
Bearing and Seal Installer
Collector Ring Installer
Drive End Shield Support Ring for Rotor Pressing
Press Tool - Spacer Ring, Roller Bearing Inner Race and Collector
Rings
Alignment Pin - Drive End Shield and Collector Ring End Shield
Removal Tool - Sliding Bushing
Holding Tool - Sliding Bushing
Inner Bearing Race Removal Tool
Puller Receiver Cup
Threaded Pin with Cone
Bearing Puller Spring Collet
Feeler Gauge 0.15 … 0.6 mm (.005 … .024 in)
Note: 4 required
Dial Indicator
Magnetic Indicator Stand
Bosch Number
Commercially Available
KDAW 9978 0 986 619 110
MMD 302
WPG 012.00
0 684 500 302
0 684 201 200
Bosch Number
Commercially Available
Commercially Available
Commercially Available
Commercially Available
Commercially Available
KDAW 9999 0 986 619 362
KDLJ 6010 0 986 618 124
KDLJ 6009
KDLJ 6021
KDLJ 6011
KDLJ 6012
KDLJ 6013
KDLJ 6018
KDLJ 6014
KDLJ 6015
KDLJ 6016
KDAW 9996
KDAW 9995/0/1
KDAW 9995/14
KDAW 9995/6
KDZV 7399
0 986 618 121
0 986 618 139
0 986 618 125
0 986 618 126
0 986 618 127
0 986 618 134
0 986 618 128
0 986 618 129
0 986 618 130
0 986 619 269
0 986 619 214
0 986 619 250
0 986 619 233
0 986 618 378
EFAW 7
T-M 1
1 687 233 011
4 851 601 124
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7.3 Lubricants and Adhesives
Description
Roller Bearing Grease
Molycote Paste
Adhesive Dispersant
Silicon Paste
Repair and Testing Instructions for T1 Page 13
Alternator 0120 689 552 Edition 001
Manufacturer
Number
UNIREX N3
Ft1 v 34
VS 15164-Ft
Ft 70 v 1
KK57v1
Ft2v4
Bosch Number
5 975 560 125
5 700 009 000
5 975 560 000
5 700 040 000
5 703 151 000
5 700 083 005
7.3.1 Lubricant Quantities
Bottom of Roller Bearing
Collector End Shield Radial Seal
Roller Bearing
2 g (0.07 oz.)
2 g (0.07 oz.)
2…2.5 g (0.07…0.09 oz.)
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Repair and Testing Instructions for T1 Page 14
Alternator 0120 689 552 Edition 001
8 Exploded View
Figure 4 Alternator Exploded View
Item
1
2
3
6
6/9
10
11
12
12/13
15
17
17/3/8
17/3/801
Designation
Drive End Shield
Ball Bearing
Cover Plate
Rotor
Collector Ring
Roller Bearing
Collector-Ring End Shield
Rectifier
Seal
Washer & Screw Assembly
Transistor Regulator
Compression Spring
Carbon-Brush Set
17/10 Gasket
18 Stator
19 Spring Lock Washer
Item
20
21
23
42
43
53
55
56
90
91
93
94
95
713
722
Designation
Plain Washer
Oval-Head Screw
Washer & Screw Assembly
Suppression Capacitor
Oval-Head Screw
Fan
Stud
Expansion Bushing
Retainer
Support Ring
Spacer Ring
Radial Seal
Protective Cap
Air-Intake Cover
Grommet
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Repair and Testing Instructions for T1 Page 15
Alternator 0120 689 552 Edition 001
9 Alternator Disassembly and Testing
9.1 Rear Cover Removal
1.
2.
Clamp alternator in clamping fixture KDAW 9999 (Bosch Number 0 986 619 362).
Remove four nuts holding on the air intake cover. (Figure 5)
Figure 5 Air Intake Cover Removal (1)
Note: The voltage regulator must be removed before any further disassembly of the alternator takes place. The brushes of the regulator can break if the regulator is not removed before any other disassembly takes place.
9.2 Voltage Regulator Removal
1. Remove the three (3) screws that secure the regulator to the collector ring end shield. (Figure 6)
2. Carefully remove the voltage regulator from the collector ring end shield.
Note: The brushes of the regulator will break if the regulator is not removed before any other disassembly of the alternator takes place.
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Repair and Testing Instructions for T1 Page 16
Alternator 0120 689 552 Edition 001
Figure 6 Voltage Regulator (1) and Suppression Capacitor (2)
9.2.1 Brush Replacement
1. The exposed length of the carbon brushes must be measured to determine if they require replacement.
Measure the length of each brush. If the exposed brush length is less than 7 mm (0.276"), the brush must be replaced. (Figure 7)
Figure 7 Brush Length Measurement
2. To replace the brushes, the brush lead must be unsoldered and the brush removed from the regulator.
3. Insert the new brush into the regulator and solder the brush lead to the regulator.
Note: Use only rosin-core solder to attached the brush lead.
4. Check the brushes for freedom of movement after they are soldered.
5. Measure the exposed length of the new brushes. The exposed length should be 16 mm (0.630")
9.3 Noise Suppression Capacitor Testing and Removal
1. Disconnect the suppression capacitor from terminal B+.
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Repair and Testing Instructions for T1 Page 17
Alternator 0120 689 552 Edition 001
2. Connect Multimeter MMD 302 (Bosch Number 0 684 500 302) or equivalent to the lead of the suppression capacitor and the B- terminal of the alternator. (Figure 8)
Figure 8 Testing of Suppression Capacitor
3. Measure the capacitance of the suppression capacitor. If the capacitance does not read between 1.8 and
2.6 l F (microfarad), the capacitor must be replaced.
4. Remove the screw that secures the suppression capacitor and remove capacitor.
Note: After removing the suppression capacitor from the alternator, the capacitor lead should be shorted to the capacitor-mounting strip to discharge the capacitor. Failure to do so may cause the capacitor to discharge while being cleaned .
9.4 Pulley and Fan Removal
1. Using a 14-mm hex socket to hold the rotor shaft. Loosen and remove pulley-retaining nut with a box wrench. (Figure 9)
Note: Do not use an air impact gun to remove the nut as the force of the impact may cause damage to the alternator bearings.
Figure 9 Pulley and Fan Removal
2. Remove the pulley and cooling fan from the alternator.
9.5 Separation of Drive Shield and Collector End Shield
Note: With a scribe, mark the relationship between the drive end shield and the collector ring end shield. This will assist in the realigning of the two shields upon reassembly.
1. Loosen and remove the four (4) outer Oval-head screws which hold the end shields together. (Figure 10)
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Repair and Testing Instructions for T1 Page 18
Alternator 0120 689 552 Edition 001
2. Slide the drive end shield and rotor out of the collector end shield.
Figure 10 Drive End Shield Removal
9.6 Rectifier Assembly Testing
Note: The following testing of the rectifier is to be performed with the rectifier assembly installed and wired in to the stator.
1. With the rectifier assembly still installed in the collector end shield, testing of the rectifier is to be performed.
a. Using tester WPG 012.00 (Bosch Number 0 684 201 200) (Figure 11) i) Connect the negative (black) lead of the tester to the collector end shield and the positive (red) lead to each of the stator connection solder joints.
ii) Connect the positive (red) lead of the tester to the B+ Terminal and the negative (black) lead to each of the stator connection solder joints.
iii) Connect the positive (red) lead of the tester to the D+ Terminal and the negative (black) lead to each of the stator connection solder joints.
The rectifier assembly is reusable if the tester remains in green zone. If the rectifier assembly fails any test, one or more of the diodes are defective and the whole assembly must be replaced.
Figure 11 Testing of Rectifier Assembly
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Repair and Testing Instructions for T1 Page 19
Alternator 0120 689 552 Edition 001 b. Using a Diode Tester i) Connect the negative (black) lead of the tester to the collector end shield and the positive (red) lead to each of the stator connection solder joints. No current should pass through the rectifier assembly.
ii) Connect the positive (red) lead of the tester to the collector end shield and the negative (black) lead to each of the stator connection solder joints. Current should pass through the rectifier assembly.
iii) Connect the positive (red) lead of the tester to the B+ Terminal and the negative (black) lead to each of the stator connection solder joints. No current should pass through the rectifier assembly.
iv) Connect the negative (black) lead of the tester to the B+ Terminal and the positive (red) lead to each of the stator connection solder joints. Current should pass through the rectifier assembly.
v) Connect the positive (red) lead of the tester to the D+ Terminal and the negative (black) lead to each of the stator connection solder joints. No current should pass through the rectifier assembly.
vi) Connect the negative (black) lead of the tester to the D+ Terminal and the positive (red) lead to each of the stator connection solder joints. Current should pass through the rectifier assembly.
If the rectifier assembly fails any test, one or more of the diodes are defective and the whole assembly must be replaced.
9.7 Removal and Testing of Stator Assembly
1. With tester WPG 012.00 or Multimeter MMD 302 set to read 0 to 0.5 W , test the resistance of the stator while it is still attached to the rectifier assembly. Connect the test leads between the phase outputs of the stator. Repeat the test until all three phases of the stator has been tested. A good stator will read between
0.036 W and 0.040 W . (Figure 12)
Figure 12 Stator Resistance Testing
2. Unsolder the stator phase connections from the rectifier assembly with a soldering gun or iron.
3. Bend open any bent-over lead connections with a screwdriver or pliers and pull the stator leads from the rectifier eyelets.
Note: The insulation tester applies a voltage of 80 VAC to the stator. Voltages of 80V can be fatal.
When performing this test, observe care is used in handling the stator and any component or surface that is exposed to the stator. Use insulated gloves and do not touch the work surface until all tests are completed.
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Repair and Testing Instructions for T1 Page 20
Alternator 0120 689 552 Edition 001
4. Using insulation tester KDAW 9983 (Bosch Number 0 986 619 110) or equivalent, apply 80 VAC to each of the stator phase leads with one probe while the other probe is in contact with the exterior of the stator.
(Figure 13)
No continuity should be present. Any continuity between the stator phase leads and the exterior of the stator indicates a breakdown of the stator insulation and a short to ground. If continuity is present, the stator must be replaced.
Figure 13 Stator Insulation Testing
9.8 Rectifier Assembly Removal
1. Loosen and remove the three screws that hold the rectifier to the collector end shield. (Figure 14)
2. Unsolder the W terminal from the rectifier assembly.
Figure 14 Rectifier Assembly Removal
3. Remove the nuts holding terminals B+, B- and D+ to the collector end shield.
Note: Do not attempt to remove the studs from the rectifier assembly. Terminals B+, B- and D+ are permanently attached to the rectifier assembly. Terminal W is attached to the collector end shield. Do not loosen Terminal W.
4. Remove the rectifier assembly from the collector end shield.
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Repair and Testing Instructions for T1 Page 21
Alternator 0120 689 552 Edition 001
9.9 Dampening Resistor Testing and Removal
1. The W Terminal incorporates a dampening resistor. Using a Multimeter MMD 302, connect one lead to the exterior portion of the W terminal and connect the other lead to the other side of the W Terminal. The
Multimeter should read between 3.1 and 3.5 k (kilohm). If the resistance is above or below this range, the
W terminal is to be replaced as an assembly. (Figure 15)
Figure 15 Testing of W Terminal Dampening Resistor
2. Loosen the nut retaining terminal W to the collector end shield.
3. Remove terminal W.
9.10 Removal of Collector End Shield Bearing and Seal
1. Insert extractor KDLJ 6009 (Bosch Number 0 986 618 121) into bearing.
2. Screw threaded rod KDAW 9995/14 (Bosch Number 0 986 618 214) into extractor KDLJ 6009.
3. Slide the receiver cup KDAW 9995/0/5 (Bosch Number 0 986 619 250) onto threaded rod.
4. Screw on the handle, rotate until the bearing, and seal come out of the collector end shield. (Figure 16)
Figure 16 Bearing and Seal Removal
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Repair and Testing Instructions for T1 Page 22
Alternator 0120 689 552 Edition 001
5. If the roller bearing is stuck in end shield, proceed as follows: a. Remove extractor KDLJ 6009 from the bearing.
b. Destroy the bearing cage with a screwdriver or similar tool.
c. Remove rollers from bearing.
d. Insert spring collet KDAW 9995/6 (Bosch Number 0 986 619 233) into bearing outer race.
e. Screw threaded rod KDAW 9995/14 into extractor KDAW 9995/6.
f. Slide the receiver cup KDAW 9995/0/5 onto threaded rod.
g. Screw on handle and rotate until the bearing race comes out of the collector end shield.
9.11 Removal of Sliding Bushing in Collector End Shield
1. Place collector end shield in an arbor press, support mounting/pivot boss on mandrel KDLJ 6016 (Bosch
Number 0 986 618 130). (Figure 17)
2. Place bushing mandrel KDLJ 6015 (Bosch Number 0 986 618 219) on sliding bushing.
3. Press sliding bushing out of collector end shield into mandrel KDLJ 6016.
Figure 17 Sliding Bushing Removal
9.12 Removal of Rotor from Drive End Shield
1. Place drive end shield onto pressing ring KDLJ 6013 (Bosch Number 0 986 618 127).
2. Place pressing ring into an arbor press. (Figure 18)
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3. Press out rotor.
Repair and Testing Instructions for T1 Page 23
Alternator 0120 689 552 Edition 001
Figure 18 Pressing out Rotor
4. Remove spacer ring from rotor shaft.
Notes: Protect the threads of the rotor from damage prior to pressing. Always replace the drive end bearing if the rotor has been pressed out. Therefore, only remove the rotor if;
• the rotor is to be replaced
• the excitation winding of the rotor is to be replaced
• the drive end bearing/spacer ring is to be serviced
• the rotor collector rings are to be replaced
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Repair and Testing Instructions for T1 Page 24
Alternator 0120 689 552 Edition 001
9.13 Removal of Bearing and Seal from Drive End Shield
1. Loosen and remove the four (4) screws holding the bearing cover plate. (Figure 19)
2. Remove the spacer ring (Refer to arrow in Figure 19).
3. Remove the bearing from the drive end shield.
Figure 19 Drive End Bearing Removal
9.14 Removal of Collector Ring End Inner Bearing Race from Rotor
1. With a universal bearing puller, remove the inner race of the endshield bearing. (Figure 20)
Notes: Place jaws of the puller yoke behind the inner-bearing race and pull the bearing race only. Do not place the yoke behind the spacer ring. Pulling both the bearing and the spacer ring at the same time may damage the rotor. The inner bearing race must be replaced anytime the collector end shield bearing is replaced.
2. Reposition the puller and remove the spacer ring from the rotor shaft.
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Figure 20 Inner Bearing Race Removal
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Repair and Testing Instructions for T1 Page 25
Alternator 0120 689 552 Edition 001
9.15 Rotor Inspection
1. Using electric tester ETE 014.00 or Multimeter MMD 302, measure the resistance between the two collector rings of the rotor. The resistance measured should be between 7.5 and 8.3 . (Figure 21)
Figure 21 Rotor Resistance Testing
2. Using insulation tester KDAW 9983 or equivalent, apply 80 VAC to the rotor claw poles and each of the collector rings. If the insulation tester lights, there is a short to ground within the rotor. (Figure 22)
Figure 22 Rotor Insulation Testing
Note: The insulation tester applies a voltage of 80 VAC to the rotor. Voltages of 80V can be fatal.
When performing this test, observe care is used in handling the rotor and any component or surface that is exposed to the rotor. Use insulated gloves and do not touch the work surface until all tests are completed.
3. Mount the rotor in a pair of V-Blocks at the rotor bearing points.
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Repair and Testing Instructions for T1 Page 26
Alternator 0120 689 552 Edition 001
4. Position dial indicator (Magnetic Base T-M 1 (Bosch Number 4 851 601 124) and Dial Indicator EFAW 7
(Bosch Number 1 687 233 011)) to measure the concentricity of the rotor at:: (Figure 23) a. Outer diameter of rotor, maximum run-out 0.05 mm (0.002 in). If the run-out of the rotor exceeds the maximum, the rotor must be replaced.
Figure 23 Rotor Concentricity Measurement b. Each collector ring, maximum run-out 0.03 mm (0.0012 in). If the run-out exceeds the maximum, the collector rings can be machined down to a minimum of 31.5 mm (1.240 in) diameter. If the required machining causes the collector ring diameter to drop below the minimum dimension, the collector ring(s) must be replaced.
9.16 Collector Ring Replacement
1. Before the collector rings can be removed, the spacer ring from the end of the rotor must be removed.
Refer to Section 9.14 "Removal of Inner Bearing Race from Rotor."
2. Unsolder the rotor leads from each collector ring.
3. With a universal bearing puller, remove each collector ring one at a time from the rotor. (Figure 24)
Figure 24 Collector Ring Removal
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Alternator 0120 689 552 Edition 001
10 Alternator Assembly
10.1 Rotor Assembly
1. Position rotor in arbor press with the drive end pointing down.
2. Press the lead for the rotor winding into the slot of the rotor.
3. Slide the collector rings onto the rotor shaft as far as possible by hand. Make sure the lead for the rotor windings does not become damaged while sliding the collector rings over the lead.
4. Lining up the slot in tool KDLJ 6012 (Bosch Number 0 986 618 126) with the rotor lead, press the collector rings onto the rotor as far as possible. (Figure 25)
Figure 25 Pressing on Collector Rings
5. Solder each of the rotor winding leads to one of the collector rings with rosin core solder.
6. After soldering, touch up surface of collector ring to remove any excess solder from the brush contact surface.
7. Press on collector end shield bearing spacer ring with tool KDLJ 6018 (Bosch Number 0 986 618 134) until it contacts the stop on the rotor and no air gap is present. (Figure 26)
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Figure 26 Spacer Ring
Installation
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Repair and Testing Instructions for T1 Page 28
Alternator 0120 689 552 Edition 001
Note: Do not allow the spacer ring to twist while pressing onto the rotor.
8. Place the inner bearing race of the collector end shield bearing onto the rotor shaft.
9. Press the bearing onto the rotor shaft with tool KDLJ 6018. (Figure 26)
10.2 Drive End Shield Assembly
1. Insert sealed ball bearing into the drive end shield.
2. Align the holes of the bearing cover plate with the holes in the drive end shield.
3. Start the four screws which hold the bearing cover plate and tighten to 4.1 … 5.5 Nm (36.3 … 48.7 in. lbs.)
(Figure 27)
Figure 27 Drive End Bearing Retaining Screws
4. Insert bearing/fan spacer ring into the drive end shield from the fan side of the shield.
5. Place drive end shield on to an arbor press with the bearing/fan spacer ring pointed down. (Figure 28)
6. Slide support ring onto the drive end of the rotor. Make sure the under cut side of the ring faces the retaining ring on the rotor.
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Figure 28 Installing Rotor into Drive End Shield
(1) Tool KDLJ 6018 (2) Support Ring
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Repair and Testing Instructions for T1 Page 29
Alternator 0120 689 552 Edition 001
7. Place rotor into the drive end bearing.
8. Place tool KDLJ 6018 onto the end of the rotor and press the rotor into the drive end bearing until the bearing seats against the support ring.
10.3 Collector Ring End Shield Assembly
1. Pack the collector end roller bearing with 2 to 2.5 g (0.07 to 0.09 oz.) of UNIREX N3 grease.
2. Place the end shield on an arbor press.
3. Place tool KDLJ 6011 (Bosch Number 0 986 618 125) into bearing and press bearing into collector end shield. (Figure 29)
4. Pack the bottom of the collector end housing bearing bore with an additional 2 g (0.07 oz.) of UNIREX N3 grease.
5. Coat the sealing lip of the radial lip seal and pack the seal with 2 g (0.07 oz.) of UNIREX N3 grease.
Notes: Do not assemble the alternator with a dry radial seal as this will lead to seal failure and contamination of the brushes and collector rings.
Make sure there is no excess grease on the exterior of the seal before installation in the collector end shield. Excess grease on the exterior of the seal will cause contamination of the collector rings and brushes.
Figure 29 Installation of Bearing and Seal
6. Place seal onto tool KDLJ 6011 and press the seal into the collector end shield. (Figure 29)
7. Place collector end shield in an arbor press, support mounting/pivot boss on tool KDLJ 6016. (Figure 30)
8. Coat the inside of the collector end shield bore with Molycote.
9. Place sliding bushing into place on collector end shield.
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Alternator 0120 689 552 Edition 001
10. With tool KDLJ 6015, press sliding bushing into end shield until the bushing is flush with the inner surface of the mounting/pivot boss. (Figure 30)
Figure 30 Sliding Bushing Installation
11. Insert terminal W into collector end shield in location marked W. Make sure the locating lug of the terminal assembly indexes the end shield correctly.
12. Place insulator and flat washer onto terminal W.
13. Install nut and torque to 4.1 to 5.5 Nm (36.3 to 48.7 in. lbs.)
14. Install protective cap onto terminal W. (Figure 31)
Protective Cap
Figure 31 Terminal W Insulator,
Washer, Nut and Cap
10.4 Rectifier Assembly
1. Place flat washer and insulator (a) onto terminal B+ and D+ studs of the rectifier assembly. (Figure 32)
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Figure 32 Rectifier Insulators and Seal
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Alternator 0120 689 552 Edition 001
2. Coat the keyhole shaped surface of the rectifier with adhesive. (Figure 32)
3. Place the rectifier seal ring onto the keyhole shaped surface of the rectifier. Make sure the seal conforms to the shape of the keyhole.
4. Once the adhesive has cured, place the rectifier into the collector end shield. Make sure the solder lug of the W Terminal passes into the correct position of the rectifier assembly.
5. Install the insulating washer, flat washer and nut to terminal studs B+ and D+. (Figure 33)
6. Install flat washer and nut onto terminal stud B-. (Figure 33)
7. Check that the soldering lug of terminal W is still in the proper location of the rectifier assembly.
Figure 33 Terminal B+, B- and D+ Assembly
8. Torque terminal stud nuts B+, D+ and B- to: a. Terminal B+ and B-........ 10 to 13 Nm (88.5 to 115 in. lbs.) b. Terminal D+ ................... 2.4 to 3.2 Nm (21.2 to 28.3 in. lbs.)
9. Install the flat washer and second nut to terminal studs B+, D+ and B- and torque to: a. Terminal B+ and B-........ 10 to 13 Nm (88.5 to 115 in. lbs.) b. Terminal D+ ................... 2.4 to 3.2 Nm (21.2 to 28.3 in. lbs.)
10. Install the three (3) rectifier mounting screws and torque to 1.3 to 1.7 Nm (11.5 to 15 in. lbs.).
11. Solder the soldering lug of terminal W to the solder pad of the rectifier assembly with rosin core solder.
(Figure 34 )
Figure 34 Rectifier Mounting and
Soldering of Terminal W
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Alternator 0120 689 552 Edition 001
10.5 Stator Assembly
1. Position the stator on the collector end shield. The side of the stator with the winding leads should be closest to the collector end shield.
2. Line up the scribed mark of the stator with the scribed mark of the collector end shield. If either the stator or collector end shield was replaced, a new mark should be scribe across the new part using the replaced component as a reference.
3. Place each of the stator leads into a corresponding soldering lug of the rectifier assembly. After the lead is through the soldering lug, bend the lead so it forms a U around the lug. (Figure 35)
Figure 35 Soldering of Stator Leads
4. Solder each of the stator leads to the rectifier assembly with rosin core solder.
10.6 Rotor and Drive End Shield Installation
1. Place collector end shield and stator assembly on a suitable surface so the rotor and drive end shield assembly can be lowered into place
2. Guide the rotor and drive end shield assembly until the inner bearing race of the collector end bearing enters the roller bearing. Once the inner race enters the bearing, lower the assemblies completely into the collector end shield.
3. Insert guide pin KDLJ 6014 (Bosch Number 0 986 618 128) through the sliding bushing of the collector end shield and the bushing of the drive end shield. (Figure 36)
4. Start the four (4) drive end shield to collector end shield screws.
5. Place the alternator assembly into clamping fixture KDAW 9999.
6. Insert four (4) 0.3 mm (0.012 in) feeler gauges between the stator and the rotor. The feeler gauges should be place in four diametrically opposed positions. (Figure 36)
7. Torque the drive end shield to collector end shield screws to 7.2 to 9.7 NM (21.2 to 28.3 in. lbs.).
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8. Remove the four feeler gauges from between the stator and rotor.
9. Turn the rotor by hand. The rotor should rotate freely by hand. If the rotor does not turn freely, loosen the drive end shield to collector end shield screws and repeat steps 6, 7, 8 and 9.
10. While rotating the rotor by hand, listen for contact between the rotor and the stator or stator leads. If any contact sound is heard, the rotor and drive end shield assembly must be removed, the cause determined and repaired before continuing. Once the problem has been corrected, start at step 1 of this section.
Figure 36 Drive End Shield, Stator and Collector End Shield Assembly
(1) Feeler Gauge (2) Tool KDLJ 6015
11. Remove the alignment pin KDLJ 6014 from the alternator.
10.7 Regulator and Capacitor Installation
1. Depress the carbon brush closest to the regulator into the regulator/brush holder.
2. Insert a straightened paper clip (1 to 1.3 mm dia. x 40mm) into the hole of the regulator until the pin holds the brush in place.
3. Pivot the regulator into the opening of the alternator. Once the brush holder is inside the alternator cavity, slowly remove the paper clip and allow the brushes to extend from the holder. (Figure 37)
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Figure 37 Regulator Installation
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Alternator 0120 689 552 Edition 001
4. Align the mounting holes of the regulator to holes of the alternator housing.
Note: When aligning the mounting holes, pay attention to the force used as damage can occur to the brushes.
5. Install the three (3) regulator mounting screws and torque to 1.3 to 1.7 Nm (11.5 to 15 in. lbs.). (Figure 38)
6. Install capacitor on collector end shield and tighten mounting screw to 4.3 to 5.7 Nm (38.0 to 50.4 in. lbs.).
(Figure 38)
Figure 38 Capacitor Installation
(1) Voltage Regulator (2)
7. Connect lead of capacitor to spade terminal +.
8. Install air intake cover onto alternator. Do not torque cover until it has been installed on the vehicle/engine.
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Alternator 0120 689 552 Edition 001
11 Functional Testing
11.1 General Information
The functional testing of the alternator is broken into two categories, Power Output and Voltage Trace
Evaluation. All of the tests describe here are performed with the voltage regulator installed on the alternator.
11.1.1 Power Output Tests
The power output tests verify the capability of the alternator to produce rated current and voltage at different speeds. This test requires a test bench of sufficient horsepower to turn a fully loaded alternator at a given speed. Additionally, the test bench must have the ability to inductively load the alternator to its rated amperage for an extended amount of time.
The power output test is to be performed anytime the alternator is suspected of being defective or if the alternator has been disassembled.
11.1.1.1 Test Bench Requirements
To perform the power output test of this series alternator, a test bench must meet the following minimum criteria.
Characteristic
Variable Speed Control
Drive Motor
Load Bank Capability
Output Voltage Capability
Minimum Specification
0 - 12,000 RPM
4 kW (5.4 hp)
170 A @ 28 V for 10 minutes
80 A @ 28 V for 30 minutes
28 V
11.1.2 Voltage Trace Evaluation
The voltage trace evaluation compares the output of the alternator as viewed on an oscilloscope to know oscilloscope patterns. The voltage trace evaluation is an important tool for diagnostics of an alternator that cannot meet the criteria of the power output test. Proper interpretation of the waveforms obtained can lead a technician to the defective component of a failed alternator. The voltage trace evaluation is done while the alternator is still mounted to the alternator test bench. Most any oscilloscope, which is capable of accepting the alternator voltage output, is useable for this evaluation.
11.2 Power Output Testing
11.2.1 Test Bench Mounting
1. Mount the alternator to the test bench per the operating instructions of the test bench manufacturer.
2. Connect the drive system of the test bench to the alternator as per the instructions of the test bench manufacturer.
Note: Only perform the power output tests with the fan pulley installed on the alternator. Failure to test the alternator with the correct fan installed can cause the alternator to overheat and damage the internal components of the alternator.
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3. Connect the test leads of the test bench to the alternator as follows: a. Connect the +24 v lead of the test bench to the B+ terminal of the alternator.
b. Connect the -24 v lead of the test bench to the B- terminal of the alternator.
c. Connect the charging indicator lamp of the test bench to the D+ terminal of the alternator.
Note: Refer to test bench manufacturers operating instructions for correct terminology of test leads
Refer to figure 39 for a schematic outline of alternator to test bench connections. Compare this schematic to the hook-up schematic of your test bench.
Figure 39 Alternator Test Bench Hook-up Schematic
(1) Variable Load Resistor
(2) Ammeter (Alternator Output)
(3) Charging Indicator Lamp
(4) Voltmeter (Regulated Voltage)
(5) Ammeter
(6) Test Bench Battery
4. Make sure the test bench is set for the correct voltage and rotation before starting tests.
11.2.2 Power Output Test
1. Start test bench and increase speed to 1500 rpm, alternator speed.
2. Increase inductive load on the alternator until 76A output is achieved. As load is increased, monitor test bench speed and correct if speed drops while applying load.
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3. Hold test bench at this speed and load for 30 minutes. Monitor alternator output and speed during the test period.
4. Remove load and operate the alternator at 7000 rpm for one minute to allow the alternator to cool.
5. Refer to the test bench operating instructions and allow the load bank to cool the required amount of time before proceeding to the next test.
6. After the load bank has cooled, increase the test bench until the alternator has reached 6000 rpm.
7. Increase inductive load on the alternator until 136A alternator output is achieved. As load is increased, monitor test bench speed and correct if speed drops while applying load.
8. Hold test bench at this speed and load for 10 minutes. Monitor alternator output and speed during the test period.
9. Remove load and operate the alternator at 7000 rpm for one minute to allow the alternator to cool.
10. Refer to the test bench operating instructions and allow the load bank to cool the required amount of time before proceeding to the next test.
11. Apply a minimum load of 10A to the alternator.
12. Measure the regulated voltage of the alternator. The correct regulated voltage is between 27.6 and 28.4
volts.
13. If the alternator passes the three output tests, no further testing is required. If the alternator failed any of the three tests, proceed with the voltage trace evaluation.
11.3 Voltage Trace Evaluation
The voltage trace evaluation is a comparison of the voltage output of the alternator to know patterns. These know patterns will help identify different failed components.
11.3.1 Oscilloscope Hook-up
1. Following the manufacturer's instructions for your oscilloscope, connect the scope to the B+ and Bterminals of the alternator.
2. Adjust the oscilloscope to read 28 volts.
3. Turn on test bench and operate the alternator with a 10A load.
4. Compare oscilloscope display to the following test patterns.
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11.3.2 Normal Pattern
This image represents a properly functioning alternator. The D.C. voltage produced has a small harmonic wave.
Small spikes may be superimposed on the oscilloscope screen if the voltage regulator is regulating. Applying a load to the alternator output terminals can turn off the regulator.
In order to be able to compare oscilloscope images, the oscilloscope so the pattern fits between two vertical 10x divisions.
Figure 40 Normal Pattern
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11.3.3 Open Exciter Diode
This pattern displays a characteristic dip in the normally smooth wave characteristic of a defective exciter diode. This would require disassembly of the alternator and replacement of the rectifier assembly.
Figure 41 Open Exciter Diode
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11.3.4 Open Positive Rectifier Diode
This pattern identifies an open positive rectifier diode. In the case of multiple diodes in parallel, all of the diodes on the circuit must be open. An example is:
There are two diodes in the rectifier for each phase of the stator. Both diodes must be open for this pattern to appear.
With this type of defect, the rectifier assembly must be replaced.
Figure 42 Open Positive Rectifier Diode
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11.3.5 Open Negative Rectifier Diode
This pattern identifies an open negative rectifier diode. In the case of multiple diodes in parallel, all of the diodes on the circuit must be open. An example is:
There are two diodes in the rectifier for each phase of the stator. Both diodes must be open for this pattern to appear.
With this type of defect, the rectifier assembly must be replaced.
Figure 43 Open Negative Rectifier Diode
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11.3.6 Shorted Exciter Diode
This pattern identifies a shorted exciter diode. This would require disassembly of the alternator and replacement of the rectifier assembly.
Figure 44 Shorted Exciter Diode
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11.3.7 Shorted Positive Rectifier Diode
This pattern identifies a positive rectifier diode that is shorted. This defect requires replacement of the rectifier assembly.
Figure 45 Shorted Positive Rectifier Diode
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11.3.8 Shorted Negative Rectifier Diode
This pattern identifies a negative rectifier diode that is shorted. This defect requires replacement of the rectifier assembly.
Figure 46 Shorted Negative Rectifier Diode
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11.3.9 Open Phase of Stator
This pattern illustrates a stator with an open phase winding. This type of defect would require replacement of the stator.
Figure 47 Open Stator Phase
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SECTION 07: TRANSMISSION
1. DESCRIPTION .................................................................................................................................07-3
1.1 EATON AUTOMATIC TRANSMISSION....................................................................................07-3
1.2 ALLISON AUTOMATIC TRANSMISSION .................................................................................07-3
3. MAINTENANCE ...............................................................................................................................07-5
3.1 EATON AUTOMATIC TRANSMISSION....................................................................................07-5
3.1.1 Oil
3.1.2 Cold Check.........................................................................................................................07-5
Check...........................................................................................................................07-6
3.1.4 Lubricant Leaks ..................................................................................................................07-6
3.1.5 Coolant Leakage ................................................................................................................07-6
3.1.6 Oil and Filter Change .........................................................................................................07-7
Recommendations ........................................................................................................07-7
3.1.8 Main Parts Listing and Illustration ......................................................................................07-9
3.2 ALLISON AUTOMATIC TRANSMISSION ...............................................................................07-10
3.2.1 Cold Check.......................................................................................................................07-10
Check.........................................................................................................................07-10
3.2.3 Readout of the Oil Level Sensor ......................................................................................07-10
Recommendations ......................................................................................................07-12
3.2.6 Oil
3.2.7 Metal
3.2.8 Coolant Leakage ..............................................................................................................07-13
3.2.9 Oil and Filter Change .......................................................................................................07-13
4. TRANSMISSION REMOVAL .........................................................................................................07-14
4.1 EATON AUTOMATIC TRANSMISSION..................................................................................07-14
4.2 ALLISON AUTOMATIC TRANSMISSION ...............................................................................07-15
5. TRANSMISSION OIL COOLER REMOVAL..................................................................................07-16
5.1 TRANSMISSION WITHOUT RETARDER...............................................................................07-16
5.2 TRANSMISSION WITH RETARDER ......................................................................................07-16
6.1 EATON AUTOMATIC TRANSMISSION..................................................................................07-17
7. CLEANING AND INSPECTION OF THE TRANSMISSION ..........................................................07-18
7.1 EATON AUTOMATIC TRANSMISSION..................................................................................07-18
7.2 ALLISON AUTOMATIC TRANSMISSION ...............................................................................07-18
7.2.1 Breather............................................................................................................................07-18
8.1 EATON AUTOMATIC TRANSMISSION..................................................................................07-18
8.2 ALLISON AUTOMATIC TRANSMISSION ...............................................................................07-19
9. ALLISON TRANSMISSION PRINCIPLES OF OPERATION ........................................................07-21
07 - 1
Section 07: TRANSMISSION
10. TROUBLESHOOTING................................................................................................................07-21
10.1 EATON AUTOMATIC TRANSMISSION..................................................................................07-21
10.2 ALLISON AUTOMATIC TRANSMISSION ...............................................................................07-23
10.2.1 WTEC/Electronic Control Unit..........................................................................................07-23
10.2.2 WTEC/Troubleshooting ....................................................................................................07-23
Code Memory.................................................................................................07-23
10.2.4 Reading Codes.................................................................................................................07-24
10.2.5 Clearing Codes.................................................................................................................07-25
11. SPECIFICATIONS ......................................................................................................................07-37
ILLUSTRATIONS
FIGURE 1: EATON AST 7L TRANSMISSION .........................................................................................07-3
FIGURE 2: SHIFT CONTROL PAD..........................................................................................................07-3
FIGURE 3: GEAR DISPLAY MODULE ....................................................................................................07-3
FIGURE 4: WORLD TRANSMISSION .....................................................................................................07-4
FIGURE 5: WORLD TRANSMISSION CONTROL PAD ..........................................................................07-4
FIGURE 6: OIL LEVEL DIPSTICK (AUTO.
TRANS.) ...............................................................................07-5
FIGURE 7: COLD CHECK .......................................................................................................................07-5
FIGURE 8: HOT CHECK..........................................................................................................................07-6
FIGURE 9: DRAIN PLUGS AND FILTER.................................................................................................07-7
FIGURE 10: EATON TRANSMISSION MAIN PARTS LISTING ..............................................................07-9
FIGURE 11: OIL LEVEL DIPSTICK (AUTO.
TRANS.) ...........................................................................07-10
FIGURE 12: COLD CHECK ...................................................................................................................07-10
FIGURE 13: HOT CHECK......................................................................................................................07-10
FIGURE 14: DRAIN PLUG AND FILTERS.............................................................................................07-14
FIGURE 15: EATON TRANSMISSION CONNECTIONS ......................................................................07-15
FIGURE 16: EATON TRANSMISSION LIFTING POINTS .....................................................................07-15
FIGURE 17: ENGINE CRANKING POSITIONS.....................................................................................07-16
FIGURE 18: TRANSMISSION OIL COOLER.........................................................................................07-16
FIGURE 19: OIL COOLER INSTALLATION ..........................................................................................07-17
FIGURE 20: OIL COOLER SECTION VIEW ..........................................................................................07-17
FIGURE 21: LIFTING EYES AND SENSOR POSITION ........................................................................07-19
FIGURE 22: NUT TOLERANCE.............................................................................................................07-20
FIGURE 23: AIR PRESSURE REGULATOR (TYPICAL) ......................................................................07-20
FIGURE 24: WTEC / ELECTRONIC CONTROL UNIT ..........................................................................07-23
07 - 2
Section 07: TRANSMISSION
1. DESCRIPTION
XL2 Series vehicles may be provided with either an Eaton Autoshift AST 7L automatic transmission or an Allison World automatic transmission.
1.1 EATON AUTOMATIC TRANSMISSION
The optional Eaton AutoShift AST 7L automatic transmission is a seven-speed automatic transmission.
FIGURE 2: SHIFT CONTROL PAD
07055
FIGURE 1: EATON AST 7L TRANSMISSION 07060
Control of the transmission is done via a pushbutton shift control pad located on the lateral console. Gear select buttons located on the pad allow manual control of the transmission.
The transmission performs a self-test at powerup. It is normal for the service light to illuminate briefly at power-up. If the service light stays on or illuminates while driving, the ECM has detected a fault code. In that case have the vehicle serviced as soon as possible. Fault codes can be flashed on the control pad service light.
A gear display module informs the driver of which gear is presently engaged. A flashing number indicates the next gear to be engaged.
UP arrows indicate that the input shaft rpm is too low to engage the gear. In this situation, the transmission ECM will slightly increase engine rpm. DOWN arrows indicate the input shaft rpm is too high to engage the gear, the ECM is waiting for the shaft to slow down before allowing the shift.
07 - 3
FIGURE 3: GEAR DISPLAY MODULE
07056
1.2 ALLISON AUTOMATIC TRANSMISSION
The B500(R) World Transmission has 6 speeds with two top range (fifth and sixth) overdrives.
Total coverage is determined by dividing the highest gear ratio by the lowest gear ratio. Total coverage expresses the transmission gear ratio versatility. Transmissions with larger total coverage number have a wider variety of available ratios.
An electronic control allows the transmission to shift at exactly the right point on the engine's fuel consumption curve for best economy. Early lockup maintains the highest possible mechanical efficiency through the closely-spaced gear steps, culminating in two overdrive ratios. This combination allows progressive shifting techniques, where engine speeds are reduced for higher efficiency and lower fuel consumption.
Section 07: TRANSMISSION
FIGURE 4: WORLD TRANSMISSION
07020B
Gear selection and torque converter modes are controlled by a microcomputer-based electronic transmission management system. It is fed information regarding throttle position, operator range selection, engine speed, turbine speed, transmission output speed and various system pressures from special electronic sensors. With this information, it computes shift points and clutch pressures to meet immediate needs.
Using closed loop adaptive logic, the electronic control looks at a number of parameters during the shift, and makes minute adjustments to match the shift to desired profile stored in its memory. It then looks at these adjustments and resets the parameters, which allow the transmission to quickly compensate for variations in load, terrain or environment and to adjust for clutch wear and engine power changes.
A Diagnostic Data Reader can be connected to the electronic control unit to provide a self-check of all systems in the transmission. Four-digit trouble codes greatly reduce the time it takes to pinpoint potential problems. (Refer to heading
"10. TROUBLESHOOTING" in this section).
1.2.1 Retarder (if applicable)
This optional auxiliary braking device for the automatic transmission is integrated into the basic envelope of the transmission and transmits its braking force directly to the propeller shaft. It requires no additional length and adds only 75 pounds (34 kg) of weight. Operation of the retarder is controlled electronically by the driver's use of the brake and/or by hand control lever.
07 - 4
FIGURE 5: WORLD TRANSMISSION CONTROL PAD
07025
When activated, fluid enters a cavity and provides resistance to the turning of rotor blades revolving with the output shaft. This effectively slows the vehicle to the point where the service brakes are needed only for final stopping. The retarder is fully modulated and is compatible with ABS.
These procedures are intended only for vehicles equipped with transmission electronic controls.
When frame or other welding is required on the vehicle, the following precautions are to be taken to protect the electronic control components:
1. Disconnect the wiring harness connectors at the transmission electronic control unit.
2. Disconnect the positive and negative battery connections, and any electronic control ground wires connected to the frame or chassis.
3. Cover electronic control components and wiring to protect them from hot sparks, etc.
4. Do not connect welding cables to electronic control components.
Section 07: TRANSMISSION
3. MAINTENANCE
3.1 EATON AUTOMATIC TRANSMISSION
3.1.1 Oil Level Check
To gain access to the dipstick, open the engine compartment rear doors; dipstick is located on the radiator side of the engine (Fig. 6).
To check the transmission oil level, a cold check and a hot check must be performed. A cold check must be made between 60ºF (16ºC) and 120ºF
(50ºC). The transmission oil temperature gauge indicates the operating temperature; it is located in the MCD dashboard integrated Liquid Crystal
Display and can be viewed when selecting the
Gauge Mode (refer to ‘’Operator’s Manual’’ for added information).
FIGURE 6: OIL LEVEL DIPSTICK (AUTO. TRANS.)
07033
Note: Perform the cold check first to verify the transmission oil level before performing the hot check.
The hot check can be performed when the transmission oil reaches the normal operating temperature of 180ºF (82ºC) to 220ºF (104ºC).
Clean all dirt from around the end of the oil filler tube before removing the dipstick. Dirt or foreign matter must not be permitted to enter the oil system since it will cause valves to stick, undue wear of transmission parts, and clogged passages. Check the oil level in accordance with the following procedures and record any abnormal level on your "Maintenance Records".
Warning: When checking the oil level, be sure that the parking brake and/or emergency brakes are set and properly engaged, and the wheels are
07 - 5 choked. Unexpected and possible sudden vehicle movement may occur if these precautions are not taken.
Special care must be taken not to touch the engine coolant tubing and/or exhaust pipe, since this could cause severe burns.
Do not wear loose clothing and, stay away from rotating parts during procedure; personal injury could occur.
Always check the oil level reading at least twice when the engine is running. Consistency is important in maintaining the accuracy of the reading. If inconsistent readings persist, check the transmission breather to ensure it is clean and free of debris.
3.1.2 Cold
The purpose of the Cold Check is to determine if the transmission has enough fluid to be operated safely until a Hot Check can be made.
1. If the engine has been shut down for an extended period of time, park the vehicle on a level surface and apply the parking brake.
Caution: The oil level rises as sump temperature increases. DO NOT fill above the "Cold Run" band if the transmission oil is below normal operating temperature.
2. Run the engine for at least one minute. Shift to Drive (D) and operate the engine for 30 seconds at 1000-1500 rpm; then shift to
Reverse (R) to clear the hydraulic system of air. Finally shift to Neutral (N) and allow the engine to idle for two minutes (500 - 800 rpm).
3. While the engine is running, remove the dipstick from the tube and wipe it clean (Figs.
6 & 7).
FIGURE 7: COLD CHECK
07063
4. Insert the dipstick into the tube and then remove, checking the oil level reading (Fig.
7). Repeat the check procedure to verify the reading. If the oil reading is within the "Cold
Run" band, the level is satisfactory for operating the transmission until the oil is hot
Section 07: TRANSMISSION enough to perform a "Hot Run" check. If the oil reading is not within the "Cold Run" band, add or drain oil as necessary to bring the level within the "Cold Run" band. a at the first opportunity after the normal operating temperature of
180ºF (82ºC) to 220ºF (104ºC) is attained.
Caution: An accurate fluid level check cannot be made unless the engine is idling (500-800 rpm) in
Neutral, the transmission fluid is at the proper temperature, and the vehicle is on a level surface.
3.1.3 Hot
Caution: The oil must be hot to ensure an accurate check for this procedure. The oil level rises as temperature increases.
1. Operate the transmission in Drive (D) range until normal operating temperature is reached
180ºF (82ºC) to 220ºF (104ºC).
2. Park the vehicle on a level surface and shift to
Neutral (N). Apply the parking brake and allow the engine to idle for two minutes (500 - 800 rpm).
3. While the engine is running, remove the dipstick from the tube and wipe it clean.
4. Insert the dipstick into the tube and then remove, checking the oil level reading. Repeat the check procedure to verify the reading.
The safe operating level is anywhere within the
"Hot Run" band on the dipstick (Fig. 8). acceptable; however, drips or larger wet areas are not. Check for leaks at the rear housing, PTO, shift bar housing, converter housing to main case, and transmission controller gasket surfaces. It is also important to ensure that the leak is indeed coming from the transmission. Make sure the lubricant is not being blown back from the engine or another vehicle component.
2. There are two external lines for lubricant on the AST transmission. One lubricates the synchronizer system and the other allows the transmission lubricant to return back to the torque converter sump. Check the lines to ensure they are not leaking.
3. Check for leaks around the flywheel. Leaks in this area could be caused by a faulty gasket, loose plugs or sensors, or even the starter.
The AST transmission has what is called a
“wet housing,” which means that the flywheel housing is used as a sump for the transmission fluid. Any leaks here could cause a transmission failure.
4. The rear seal is very important in maintaining lubricant in the transmission. If the seal is improperly installed or has failed again, a catastrophic failure may occur. Check the rear seal by performing the following two steps:
• Visually inspect the rear seal for a leak. If the rear seal is suspected, then proper isolation is necessary.
FIGURE 8: HOT CHECK 07064
1. If the oil level is not within the "Hot Run" band, add or drain oil as necessary to bring the oil level within the band.
• Other leaks can give the impression that the rear seal is leaking. One possible cause is the speed sensor. Any lubricant leak above and in front of the rear seal could cause lubricant to collect around the seal. Wipe the seal with a clean rag, operate the vehicle and recheck to verify the leak path.
Note: The Cold Check is more appropriate for verifying the oil level after the first fill-up. In case of conflict, the Hot Check has priority over the
Cold Check .
Leaks
A lubricant leak could cause a catastrophic transmission failure. Check for leaks at the gasket surfaces, the lubricant lines, flywheel housing, rear seal and the cooler.
1. Visually check each gasket to ensure that no leak is present. Typically, a moist spot is
07 - 6
5. Ensure there are no leaks at the oil cooler, hoses and fittings of the cooler circuits.
Leakage
If engine coolant leaks into the transmission oil system, immediate action must be taken to prevent malfunction and possible serious damage. The transmission must be completely disassembled, inspected, and cleaned. All traces
of the coolant contamination must be removed.
Friction clutch plates contaminated with ethylene glycol must be replaced.
3.1.6 Oil and Filter Change
When it is time to change the transmission oil, there are only a few steps to follow: draining and filling the transmission, draining and filling the cooler (if equipped) and changing the oil filter.
Remember to be careful when changing the transmission oil as it may be hot.
Drain
1. Locate the drain plugs on the bottom of the transmission case and on the bottom of the torque converter housing pan (Fig. 9).
2. Place a drain pan under each drain plug.
Remove both drain plugs and allow the oil to drain completely.
Note: Remove the bottom cooler lines.
Disconnect the cooler line at the torque converter outlet. Pressurize one line with 20 PSI until all oil is forced out of the cooler. Reconnect all cooler lines.
Note: When changing lubricant type, brand, viscosity or grade, the transmission must be flushed to remove all lubricant. Flush the lubricant as per Service Manual TRSM-0062.
4. Using a 9/16” wrench, remove the three mounting bolts from the filter housing. Remove the filter housing and O-ring seal from the transmission. Remove the oil filter by pulling the filter straight off the nipple. Inspect the oil filter nipple and remove if damaged.
Section 07: TRANSMISSION
5. If required, install oil filter nipple using hydraulic sealant and tighten to 34-48 lbf-ft
(46-65 N • m). Install the oil filter on the oil filter nipple. Install O-ring and oil filter housing on the transmission. Using a 9/16” wrench, tighten the three mounting bolts to 26-32 lbf-ft
(35-43 N • m).
6. Install the transmission case drain plug and tighten to 45-50 lbf-ft (61-68 N • m). Install the torque converter housing pan drain plug and tighten to 14-20 lbf-ft (19-27 N • m).
Refill
1. Using the oil level dipstick filler tube, refill with 7 US gallons (26,5 liters) and start the engine at idle.
2. With the engine idling, continue checking and filling until proper oil level is reached
(approximately 10 U.S. gallons (38 liters)).
Note: The total volume varies depending on cooler design.
FIGURE 9: DRAIN PLUGS AND FILTER
07065
Where transmissions are concerned, lubrication is possibly the most important part of keeping a vehicle operating.
07 - 7
Section 07: TRANSMISSION
• Synthetic Dexron III or newer automatic transmission lubricant must be used in the AST model transmissions. Dexron lubricants can be used for ambient temperatures above 0 ° F (-17.8
° C).
• Synthetic Arctic Oil is approved for applications in severe cold. Arctic Oil will have an SAE grade of OW-
20. Arctic Oil may be used in temperature below 0 ° F (-17.8
° C).
Type
Synthetic Dexron ® III or Newer
Synthetic Arctic Oil
Grade (SAE)
OW-20
3.1.8 Main Parts Listing and Illustration
Ambient Temperature
Above 0 ° F (-17.8
° C)
Below 0 ° F (-17.8
° C)
FIGURE 10: EATON TRANSMISSION MAIN PARTS LISTING
3.1.9 Operating Temperatures with Oil Coolers
07061
The transmission must not be operated consistently at temperatures above 250 ° F, however, intermittent operating temperatures to 300 ° F do not harm the transmission. Operating temperatures above 250 ° F increases the lubricant’s oxidation rate and shortens its effective life. When the average operating temperature is above 250 ° F, the transmission can require more frequent oil changes or external cooling.
The following conditions in any combination can cause operating temperatures of over 250 ° F :
(1) operating consistently at slow speeds,
(2) high ambient temperatures,
(3) restricted air flow around transmission,
(4) exhaust system too close to transmission,
(5) high horsepower operation.
Internal oil coolers are available to reduce operating temperatures when the above conditions are encountered.
OIL COOLER CHART
TRANSMISSION OIL COOLERS ARE :
07 - 9
Section 07: TRANSMISSION
Recommended - With engines of 350 HP and above.
Required - With engines of 399 HP and above and GVW’s over 90,000 lbs,
- With engines of 399 HP and above and 1400 ft•lbf or greater torque,
- With engines of 450 HP and above.
- With transmission retarder installed.
Change Interval
Every 2,500 miles
Every 2 years or 250,000 miles, whichever occurs first.
3.2 ALLISON AUTOMATIC TRANSMISSION
To gain access to the dipstick, open the engine compartment rear doors ; dipstick is located on the radiator side of the engine (Fig. 10).
To check the transmission oil level, a cold check and a hot check must be performed. A cold check must be made between 60ºF (16ºC) and 140ºF
(60ºC). The transmission oil temperature gauge indicates the operating temperature; it is located in the MCD dashboard integrated Liquid Crystal
Display and can be viewed when selecting the
Gauge Mode (refer to ‘’Operator’s Manual’’ for added information).
FIGURE 11: OIL LEVEL DIPSTICK (AUTO. TRANS.)
07033
Note:
TABLE 1 : LUBRICANT CHANGE AND INSPECTION
Description
Inspect lubricant level.
Perform transmission inspection.
Perform the cold check first to verify the transmission oil level before performing the hot check.
Change transmission lubricant and filter.
The hot check can be performed when the transmission oil reaches the normal operating temperature of 160ºF (71ºC) to 200ºF (93ºC).
Clean all dirt from around the end of the oil filler tube before removing the dipstick. Dirt or foreign matter must not be permitted to enter the oil system since it will cause valves to stick, undue wear of transmission parts, and clogged passages. Check the oil level in accordance with the following procedures and record any abnormal level on your "Maintenance Records".
Warning: When checking the oil level, be sure that the parking brake and/or emergency brakes are set and properly engaged, and the wheels are choked. Unexpected and possible sudden vehicle movement may occur if these precautions are not taken.
Special care must be taken not to touch the engine coolant tubing and/or exhaust pipe, since this could cause severe burns.
Do not wear loose clothing and, stay away from rotating parts during procedure; personal injury could occur.
Always check the oil level reading at least twice when the engine is running. Consistency is important in maintaining the accuracy of the reading. If inconsistent readings persist, check the transmission breather to ensure it is clean and free of debris.
3.2.1 Cold
07 - 10
Section 07: TRANSMISSION
The purpose of the Cold Check is to determine if the transmission has enough fluid to be operated safely until a Hot Check can be made.
1. If the engine has been shut down for an extended period of time, park the vehicle on a level surface and apply the parking brake.
Caution: The oil level rises as sump temperature increases. DO NOT fill above the "Cold Run" band if the transmission oil is below normal operating temperature.
2. Run the engine for at least one minute. Shift to
Drive (D) and operate the engine for 30 seconds at 1000-1500 rpm; then shift to
Reverse (R) to clear the hydraulic system of air. Finally shift to Neutral (N) and allow the engine to idle (500 - 800 rpm).
3. While the engine is running, remove the dipstick from the tube and wipe it clean (Figs.
9 & 10).
1. Operate the transmission in Drive (D) range until normal operating temperature is reached
160ºF (71ºC) to 200ºF (93ºC).
2. Park the vehicle on a level surface and shift to
Neutral (N). Apply the parking brake and allow the engine to idle (500 - 800 rpm).
3. While the engine is running, remove the dipstick from the tube and wipe it clean.
4. Insert the dipstick into the tube and then remove, checking the oil level reading. Repeat the check procedure to verify the reading.
The safe operating level is anywhere within the
"Hot Run" band on the dipstick (Fig. 11).
FIGURE 12: COLD CHECK 07050
4. Insert the dipstick into the tube and then remove, checking the oil level reading (Fig.
10). Repeat the check procedure to verify the reading. If the oil reading is within the "Cold
Run" band, the level is satisfactory for operating the transmission until the oil is hot enough to perform a "Hot Run" check. If the oil reading is not within the "Cold Run" band, add or drain oil as necessary to bring the level within the "Cold Run" band.
5. Perform a Hot Check at the first opportunity after the normal operating temperature of
160ºF (71ºC) to 200ºF (93ºC) is attained.
Caution: An accurate fluid level check cannot be made unless the engine is idling (500-800 rpm) in
Neutral, the transmission fluid is at the proper temperature, and the vehicle is on a level surface.
3.2.2 Hot
Caution: The oil must be hot to ensure an accurate check for this procedure. The oil level rises as temperature increases.
07 - 10
FIGURE 13: HOT CHECK
07049
3. If the oil level is not within the "Hot Run" band, add or drain oil as necessary to bring the oil level within the band.
Note: The Cold Check is more appropriate for verifying the oil level after the first fill-up. In case of conflict, the Hot Check has priority over the
Cold Check ; the automatic system of verification via the shift selector has priority over the Hot
Check .
3.2.3 Readout of the Oil Level Sensor
The optional Oil Level Sensor (OLS) is designed to measure transmission oil level only when the following combination of operating conditions exist:
1. Engine must be at idle;
2.
NEUTRAL must be selected;
3. Zero output speed;
4. Transmission oil must be within a "normal" temperature band (160-250°F; 70-120°C), and;
5. Once the first four (4) conditions are met, there must be a "waiting" period (approx. 2 min., to facilitate consistent oil drainback) before oil level measurement begins.
Section 07: TRANSMISSION
To enter OLS readout mode (after meeting the conditions noted above), simultaneously press the UPSHIFT and DOWNSHIFT arrows on the shifter. If the five (5) conditions noted above are present, the display will immediately enter the reading mode. If the "waiting" period has not elapsed, the left digit of the display will become a
"chasing" digit and the right digit will count down from (8) to (1) until the waiting period is complete.
After attaining the reading mode, the display will flash "OL-OK" , "LO-01" , "HI-02" , etc., where the suffix "01" or "02" indicates the volume of oil (in quarts) either low or high.
At any time in this sequence, simultaneously pressing the UPSHIFT and DOWNSHIFT arrows directs the ECU to enter the transmission diagnostic mode as described under "10.
Troubleshooting" in this section.
D, N, or R may also be selected on the shifter at any time - the OLS mode will abort and normal transmission will commence. Shifts are not inhibited.
Oil Level Sensor (OLS) Codes
CODE
OL-OK
LO-01
LO-02
HI-01
HI-02
OL-50
OL-59
OL-65
OL-70
OL-79
OL-89
OL-95
3.2.4 Keeping Oil Clean
CAUSE OF CODE
Oil Level Is Correct
One Quart Low
Two Quarts Low
One Quart High
Two Quarts High
Engine Speed (RPM) Too Low
Engine Speed (RPM) Too High
Neutral Must Be Selected
Sump Oil Temperature Too Low
Sump Oil Temperature Too High
Output Shaft Rotation
Sensor Failure
Oil must be handled in clean containers, fillers, etc., to prevent foreign material from entering the transmission. Place the dipstick on a clean surface area while filling the transmission.
07 - 11
Section 07: TRANSMISSION
Caution: Containers or fillers that have been used to handle antifreeze or engine coolant must NEVER be used for handling transmission fluid. Antifreeze and coolant solutions contain ethylene glycol that, if introduced into the transmission, can cause the clutch plates to fail.
Recommendations
Hydraulic oils used in the transmission have an important influence on transmission reliability and durability.
In order of preference DEXRON-III and DEXRON-IIE, Castrol TranSynd Synthetic Fluid, MIL-L-2104D, and type C-4 oils (Allison approved SAE 10W or SAE 30) are recommended. Type C-4 oil is the only oil approved for use in off-highway applications. Use type SAE 30 where ambient temperature is consistently above 86ºF (30ºC). Some DEXRON-II oils are also qualified as type C-4 oils and may be used in offhighway applications. However, a DEXRON-II fluid which is not a qualified type C-4 oil must never be used in off-highway applications. Consult your local Allison dealer or distributor to determine if a DEXRON-II oil is also a qualified type C-4 oil.
Before using type C-4 oils, consult the vehicle manufacturer to ensure that materials used in tubes, hoses, seals, etc., are compatible with type C-4 oils. Also, consult your local Allison dealer or distributor to determine if the oil you have selected is an approved type C-4 oil. Ford Motor Company specification oils
M2C33-F, M2C138-CJ and M2C166-H may be used and may be intermixed with DEXRON-II oil.
OIL SPECIFICATIONS AND AMBIENT TEMPERATURE OPERATING CONDITIONS
Oil type
MIL-L-2104D, DEXRON-II, TranSynd TES 295, C-
4
Ambient temperature
120ºF (48ºC) to -25ºF (-32ºC )
MIL-L-46167 -25ºF (-32ºC) to -60ºF (-51ºC)
The use of an arctic preheat kit is recommended at temperatures below -25ºF (-32ºC). If a preheat kit is not available, the ECU will restrict full operation until the sump temperature is increased. The chart below shows the temperature ranges in which the transmission will operate. It should be noted that at lower sump temperature, the transmission's operation may be restricted.
Transmission Oil
Temperature
"DO NOT SHIFT"
Light
Operation
Below -26ºF (-32ºC)
-24ºF (-31ºC) to
+19ºF (-7ºC)
+20ºF (-6ºC) to
260ºF (126ºC)
Above 260ºF (126ºC)
ON
OFF
OFF
ON
Neutral only
Start with neutral and reverse, normal upshifts
Full operation in all ranges
Inhibits 5th and 6th ranges
7 - 12
Section 07: TRANSMISSION
Contamination
At each oil change, examine the drained oil for evidence of dirt or water. A nominal amount of condensation will emulsify during operation of the transmission. However, if there is evidence of water, check the cooler (heat exchanger) for other signs of leakage. This, however, may also indicate leakage from the engine oil system.
Metal particles in the oil (except for minute particles normally trapped in the oil filter) indicate damage has occurred in the transmission. When these particles are found in the sump, the transmission must be disassembled and closely inspected to find the source. Metal contamination will require complete disassembly of the transmission and cleaning of all internal and external circuits, coolers, and all other areas where the particles could lodge.
Caution: If excessive metal contamination has occurred, replacement of the oil cooler and replacement of all bearings within the transmission is recommended.
3.2.8 Coolant
If engine coolant leaks into the transmission oil system, immediate action must be taken to prevent malfunction and possible serious damage. The transmission must be completely disassembled, inspected, and cleaned. All traces of the coolant contamination must be removed.
Friction clutch plates contaminated with ethylene glycol must be replaced.
Initial Break-In
Coach
Coach
MTH with retarder
MTH with retarder
MTH without retarder
MTH without retarder
TABLE 2 : Oil and oil filter change intervals
5,000 miles (8 000 km)
Non-Transynd Fluid
Transynd Fluid
Non-Transynd Fluid
Transynd Fluid
12,000 miles (19300 km) or 6 months, whichever comes first
50,000 miles (80400 km) or 24 months, whichever comes first
12,000 miles (19300 km) or 6 months, whichever comes first
50,000 miles (80400 km) or 24 months, whichever comes first
Non-Transynd Fluid
Transynd Fluid
50,000 miles (80400 km) or 12 months, whichever comes first
100,000 miles (160900 km) or 24 months, whichever comes first
3.2.9 Oil and Filter Change
Transmission oil change must be performed with the vehicle on a flat and level surface and with parking brake applied. Oil and oil filter change frequency is determined by the severity of service and operating conditions of the transmission and by the filter equipment installed. See "Table 2" for oil and filter change intervals. More frequent changes may be required when operations are subject to high levels of contamination or overheating.
The procedure for changing the transmission oil and oil filters is as follows:
Drain
1. The transmission should be at an operating temperature of 160ºF (71ºC) to 200ºF (93ºC)
07 - 13
Section 07: TRANSMISSION when the oil is drained. This will ensure quicker and more complete fluid drainage.
Note: Remove transmission protective panel located underneath transmission for easier access.
2. Remove the drain plug from under the transmission (Fig. 8) and allow the oil to drain into a suitable container. Check the condition of the oil as described previously.
3. To replace the integral filters, remove twelve bolts (6 on each cover), two filter covers, two
O-rings, two square cut seals and the two filters from the bottom of the control module
(Fig. 8).
4. To install filters, pre-lube and install the two Orings, the two square cut seals followed by the filters (lube the O-ring in filter cartridge only) into the filter compartment. Index each filter/cover assembly to holes in channel plate/sump. Push the cover assembly in by hand to seat the seals.
Caution: Do not use bolts to draw the cover to sump. This can damage the cover, seal, or sump.
5. Install twelve bolts and both covers, and then tighten to 38-45 lbf•ft (51-61 N•m).
6. Inspect the drain plug and O-ring. Replace if necessary. Reinstall the drain plug and tighten to 18-24 lbf•ft (25-32 N•m).
7. Reinstall transmission protective panel some of the oil remains in the external circuits and transmission cavities.
4. TRANSMISSION
4.1 EATON AUTOMATIC TRANSMISSION
The following procedures deal with the removal of the transmission without removing the power plant cradle from vehicle. The method used to support the transmission depends upon conditions and available equipment.
1. Set transmission to "Neutral" position, apply parking brake, then set battery master switch to the "OFF" position.
2. Jack up vehicle, then place safety supports underneath body.
Caution: Only the recommended jacking points must be used as outlined in Section 18, "Body".
Note: For more clearance between the tag axle and transmission, the tag axle may be unloaded and jacked up or retracted (if applicable).
3. Remove engine splash guards and protective panels surrounding transmission.
FIGURE 14: DRAIN PLUG AND FILTERS
Refill
07052
Using the oil level dipstick filler tube, refill with
37 US qts (39 liters) and check the oil level using the previously described procedure. The refill amount is less than the initial filling because
07 - 14 transmission.
5. Remove the drain plugs on the bottom of the transmission case and on the bottom of the torque converter housing pan and allow oil to drain. Install the transmission case drain plug and tighten to 45-50 lbf-ft (61-68 N • m). Install the torque converter housing pan drain plug and tighten to 14-20 lbf-ft (19-27 N • m).
Warning: It is better to drain oil when it is still warm. Avoid contact with oil since it can be very hot and cause personal injury.
6. Remove transmission dipstick and filler tube.
7. Disconnect propeller shaft from transmission and remove its safety guard. Refer to Section
09, "PROPELLER SHAFT" .
8. Disconnect the two oil cooler hoses from transmission. Cover hose ends and fittings to prevent fluid contamination.
Warning: A significant amount of oil may drain from oil lines when they are disconnected.
9. Disconnect main power supply ring terminals and transmission interface harness (Fig. 15).
Section 07: TRANSMISSION
FIGURE 15: EATON TRANSMISSION CONNECTIONS
07066
10. Remove any locking tie, clamp and bracket that may interfere with the removal of transmission.
Support transmission using a suitable transmission jack with a minimum capacity of
1 ton, then remove the twelve transmission to flywheel housing mounting cap screws.
FIGURE 16: EATON TRANSMISSION LIFTING POINTS
07067
Caution: Make sure transmission-to-engine alignment is maintained when removing screws to avoid damaging the torque converter housing.
12. Slowly pull transmission straight out to clear the input shaft.
13. Remove the transmission.
4.2 ALLISON AUTOMATIC TRANSMISSION
The following procedure deals with the removal of the transmission without removing the power
07 - 15 plant cradle from vehicle. The methods used to support the transmission and engine depend upon conditions and available equipment.
1. Select transmission's "NEUTRAL" position, apply parking brake, then set battery master switch to the "OFF" position.
2. Jack up vehicle, then place safety supports underneath body.
Caution: Only the recommended jacking points must be used as outlined in Section 18, "BODY".
Note: For more clearance between the tag axle and transmission, the tag axle may be unloaded and jacked up or retracted (if applicable).
3. Remove engine splash guards and protective panels surrounding transmission.
Remove cross member from under transmission.
5. Remove the transmission drain plug and allow oil to drain. Inspect the drain plug washer and replace it if necessary. Reinstall the drain plug and tighten to 33-41 lbf•ft (45-56 N•m) (see
"3.2.9 Oil and Filter Change" in this section.
Warning: It is better to drain oil when it is still warm. Avoid contact with oil since it can be very hot and cause personal injury.
6. Remove transmission dipstick and filler tube.
7. Disconnect propeller shaft from transmission and remove its safety guard. Refer to Section
09, "PROPELLER SHAFT".
8. Disconnect the two oil cooler hoses from transmission. Cover hose ends and fittings to prevent fluid contamination.
Warning: A significant amount of oil may drain from oil lines when they are disconnected.
9. Disconnect all sensors on L.H. side of the transmission.
10. Disconnect main wiring harness.
11. Disconnect the air supply line (steel-braided hose) from retarder control valve (if applicable).
12. Remove any locking tie, clamp and bracket that may interfere with the removal of transmission.
Support transmission using a suitable transmission jack.
Section 07: TRANSMISSION
14. Remove the access plug from the flywheel housing on the R.H. side below starter. From access plug, remove the 12 converter-toflexible plate attaching screws. Cranking the engine to gain access to the attaching screws may be done by turning the crankshaft pulley using a suitable adapter (fig. 17).
1. Disconnect and remove the engine air intake duct mounted between the air cleaner housing and the turbocharger inlet.
Caution: To avoid damage to turbocharger, cover the turbocharger inlet opening to prevent foreign material from entering.
2. Disconnect the two transmission hoses from oil cooler. Cover hose ends and fittings to prevent fluid contamination.
Warning: A significant amount of oil may drain from oil lines when they are disconnected.
3. Unfasten the constant-torque hose clamps and remove the two hoses.
FIGURE 17: ENGINE CRANKING POSITIONS 01061
Caution: Do not rotate alternator shaft clockwise to avoid removing tension on belt.
15. Remove the 12 screws retaining the torque converter housing to the flywheel housing.
Caution: Make sure transmission-to-engine alignment is maintained when removing screws to avoid damaging torque converter housing.
16. Remove the transmission rubber mount above transmission by removing the nut, bolt and washer over the rubber and its support.
Remove the bracket from transmission (only if the vehicle is equipped with a retarder).
17. Slowly pull transmission straight out to clear the engine.
18. Remove the transmission.
5. TRANSMISSION OIL COOLER REMOVAL
5.1 TRANSMISSION WITHOUT RETARDER
Stop engine and allow engine to cool. Close both heater line shutoff valves (refer to Section
05 ‘’Cooling’’ ).
To drain the cooling system, proceed as per
Section 05 ‘’Cooling’’ , paragraph 5: Draining. If the cooling system is contaminated, flush system as per Section 05 ‘’Cooling’’ , paragraph
7: Flushing .
07 - 16
FIGURE 18: TRANSMISSION OIL COOLER
07031
4. Unscrew the four holding nuts and remove the U-bolts, remove the oil cooler from engine compartment.
5. Reinstall transmission oil cooler by using reverse procedure.
5.2 TRANSMISSION WITH RETARDER
This specification covers the procedure on installing the removable tube bundle into the shell.
Stop engine and allow engine to cool. Close both heater line shutoff valves (refer to Section
05 ‘’Cooling’’ ).
To drain the cooling system, proceed as per
Section 05 ‘’Cooling’’ , paragraph 5: Draining. If the cooling system is contaminated, flush system as per Section 05 ‘’Cooling’’ , paragraph
7: Flushing .
1. Disconnect and remove the engine air intake duct mounted between the air cleaner housing and the turbocharger inlet.
Caution: To avoid damage to turbocharger, cover the turbocharger inlet opening to prevent foreign material from entering.
2. Disconnect the two transmission hoses from oil cooler. Cover hose ends and fittings to prevent fluid contamination.
Warning: A significant amount of oil may drain from oil lines when they are disconnected.
3. Unfasten the constant-torque hose clamps and remove the two hoses.
4. Unscrew the four holding nuts and remove the straps, remove the oil cooler from engine compartment.
Section 07: TRANSMISSION
Note: When inserting the floating tube bundle, be certain that the oil ports on the shell are orientated properly with the baffles on the tube bundle, (this will ensure maximum oil flow across the tube bundle.
10. Care to be taken to ensure tube bundle and tube plate sealing surfaces are not damaged during the installation process. Insert the tube bundle with the smaller end first into the shell until snug.
FIGURE 19: OIL COOLER INSTALLATION
07053
5. Unscrew the bolts and remove the water bonnets, remove the tube bundle. Clean and oil, (mineral oil is sufficient), inside of the shell.
6. Oil, (mineral oil is sufficient), and stretch all o’rings, stretching the o’rings slightly will help hold them in place during installation. It is mandatory to replace all o’rings after a unit is disassembled.
Note: One end of the shell is larger than the other end and the tube bundle can only be inserted one way.
7. Inspect, (beveled areas are critical), and oil,
(mineral oil is sufficient), tube bundle.
8. Insert O-rings into the grooves on the shell,
(one large and one small), inspect O-rings to ensure they are seated properly.
9. Place shell on solid surface with the smaller end down.
07 - 17
FIGURE 20: OIL COOLER SECTION VIEW
07054
11. While handling the unit be careful that the tube bundle does not slide out. Inspect the
O-ring on smaller end and ensure that it is properly seated.
12. Slight force will be required to fully seat the tube bundle. A press is recommended being used to ensure equal force is applied to the tube bundle. After the tube bundle is fully seated, inspect the ends to ensure the orings were not damaged during the installation.
Place proper size O-rings onto the 45º chamfers on the tube bundle and install the water bonnets. Tighten bolts snug to compress O-rings.
Caution: Do not use air or electric impact wrenches while tightening bolts. reverse procedure.
6. TRANSMISSION DISASSEMBLY AND
REASSEMBLY
6.1 EATON AUTOMATIC TRANSMISSION
Section 07: TRANSMISSION
Refer to ‘’Eaton Fuller’’ Service Manual, Direct
Parts Shipment Program and Troubleshooting
Guide annexed to this section.
7. CLEANING AND INSPECTION OF THE
TRANSMISSION
7.1 EATON AUTOMATIC TRANSMISSION
When performing preventive maintenance inspections, several items must be checked. It is important, however, to perform every step to insure the transmission meets its life expectancy. Proper preventive maintenance consists of the following:
1. Check the transmission oil level;
2. Inspect under the vehicle for loose or missing bolts;
3. Check the transmission for oil leaks;
4. Inspect the rear transmission seal;
5. Worn or frayed electrical harnesses, improper routing.
Caution: DO NOT pressure wash the transmission electrical connectors. Water and detergent will cause the contacts to corrode or become faulty.
7.2 ALLISON AUTOMATIC TRANSMISSION
The exterior of the transmission should be cleaned and inspected at regular intervals. The length of service and severity of operating conditions will determine the frequency of such inspections. Inspect the transmission for:
1. Loose bolts (transmission and mounting components);
2. Oil leaks (correct immediately);
3. Loose, dirty, or improperly adjusted throttle sensor linkage;
4. Damaged or loose oil lines;
5. Worn or frayed electrical harnesses, improper routing;
6. Worn or out of phase drive line U-joint and slip fittings.
Caution: DO NOT pressure wash the transmission electrical connectors. Water and detergent will cause the contacts to corrode or become faulty.
7.2.1 Breather
The breather is located on the engine, flywheel side near the valve cover. It serves to prevent pressure build-up within the transmission and must be cleaned to keep the passage opened.
The prevalence of dust and dirt will determine the frequency at which the breather requires cleaning. Use care when cleaning the engine.
Spraying steam, water or cleaning solution directly at the breather can force the water or solution into the transmission. Always use care when removing the hose connector from transmission to prevent the entry of foreign matter.
8. TRANSMISSION
8.1 EATON AUTOMATIC TRANSMISSION
Note: For more clearance between the tag axle and transmission, the tag axle may be unloaded and jacked up, or retracted (if applicable).
1. Handle the transmission carefully to avoid damage to the transmission components and to surrounding vehicle components.
2. Never set the transmission directly on the oil pan. If the pan is damaged or bent inward, the internal suction screen should be inspected for damage.
3. Use a hoist or a transmission jack that permits precise control of transmission movement during installation.
4. Use the three transmission lifting eyes provided. The lifting eye position must not be changed on the transmission.
Note: Refer to figure 21 for lifting eye and sensor retaining bolt locations. These bolts can not be used for brackets or for any other purpose.
07 - 18
Section 07: TRANSMISSION
FIGURE 21: LIFTING EYES AND SENSOR POSITION
07068
5. Use a three point lift chain or transmission jack with a minimum capacity of 1 ton. Adjust lift chain or transmission jack to obtain the same relative angle as the engine.
6. Lubricate the torque converter center pilot and the transmission O-ring seal with soluble grease or equivalent.
7. Align the converter splines and the flywheel splines to mesh and push the transmission into the flywheel ring and housing. Pushing by hand should be the only force required to seat the transmission O-ring into the housing.
If interference is encountered, move the transmission away from the engine to investigate the cause.
8. Align the converter housing bolt holes with the engine flywheel housing bolt holes and install all the cap screws finger tight.
Caution: The converter housing must be flush against the engine flywheel housing before tightening any cap screws. Do not use the cap screws to seat housing.
9. Tighten four mounting cap screws at 90 ° intervals around the converter housing, then tighten the remaining transmission mounting cap screws using the recommended torque specifications (37-50 lbf-ft when using 7/16-
14 x ¼ SAE grade 5 minimum zinc chromate hex head flanged cap screws with sealant).
Caution: Do not tighten any mounting cap screws until all cap screws have been installed and finger tightened. Do not remove the transmission support chain or jack until all mounting cap screws have been tightened.
Install the transmission rubber mount between the rubber support and the frame with a bolt, nut and washer. Tighten the nut until the tolerance is met.
11. Remove jack from under transmission.
07 - 19
12. Reconnect main power supply ring terminals and transmission interface harness.
13. Reinstall clamps, brackets, and replace locking ties previously removed during removal procedure.
14. Reinstall the two oil cooler hoses previously removed from the transmission.
15. Install propeller shaft and its safety guard.
Refer to Section 09, "PROPELLER SHAFT" .
16. Install cross member under transmission.
17. Install engine splash guards.
Install tag axle wheels (if previously removed).
19. Make sure that the drain plugs are in place, then refill transmission. Check and adjust oil level.
8.2 ALLISON AUTOMATIC TRANSMISSION
Note: For more clearance between the tag axle and transmission, the tag axle may be unloaded and jacked up, or retracted (if applicable).
1. With the access plug removed, align one of the 12 attaching screw holes in the flexible plate with the access opening (starter side).
2. Place the transmission on a transmission jack.
3. Install a headless guide bolt into one of the 12 threaded holes for flexible plate attaching screws in the flywheel.
4. Lubricate the flywheel center pilot boss with molybdenum disulfide grease (Molycote G, or equivalent).
5. Raise transmission and position the flywheel pilot boss into the flexible plate adapter. Align the guide bolt previously installed in the flywheel with the flexible plate hole facing the access opening in the flywheel housing.
Warning: Severe damages and/or personal injury can occur if transmission is not adequately supported.
6. Seat the transmission against the engine flywheel housing. NO FORCE IS
REQUIRED. If interference is encountered, move the transmission away from engine, then investigate the cause.
Section 07: TRANSMISSION
FIGURE 22: NUT TOLERANCE
07014
Caution: The torque converter housing must be seated against the flywheel housing prior to tightening any screws. DO NOT USE SCREWS
TO SEAT THE HOUSING.
7. Start all torque converter housing screws, then tighten four of them gradually and in a criss-cross sequence around the housing.
Tighten the 12 remaining screws.
Recommended torque is between 42-50 lbf•ft
(57-68 N•m).
8. Remove the guide bolt through the access opening in the flywheel housing. Replace it with a self-locking screw, finger-tighten then start the remaining screws; tighten to 17-21 lbf•ft (23-28 N•m). Place a wrench on the crankshaft pulley attaching screw to turn the converter to gain access to the threaded holes.
9. Reinstall the access plug.
10. If the vehicle is equipped with a retarder; install the bracket on the transmission and tighten the bolt to 71-81 lbf•ft (96-110 N•m).
Install the transmission rubber mount between the rubber support and the frame with a bolt, nut and washer. Tighten the nut until the tolerance of 58 ± 2 mm is met (Fig.
12).
11. Remove jack from under transmission.
12. Connect all sensors.
13. Connect the main wiring harness.
14. Connect the air supply line (steel-braided hose) to the retarder control valve (if applicable).
15. Connect the two transmission oil cooler hoses as they were previously.
16. Reinstall clamps and brackets, and replace locking ties previously removed during removal procedure.
17. Install propeller shaft and its safety guard.
Refer to Section 09, "PROPELLER SHAFT".
18. Install transmission dipstick and filler tube.
19. Install cross member under transmission.
20. Install engine splash guards.
21. Adjust the retarder pressure to 80 ± 3 psi with the air pressure regulator. For more information refer to Section 12, "BRAKE AND
AIR SYSTEM ", under heading "AIR
PRESSURE REGULATOR".
The air pressure regulator is located at back of engine compartment, on R.H. side (Fig. 23) or in the
R.H. side rear service compartment.
22. Make sure that the drain plug is in place, then remove the transmission dipstick and pour approximately 37 US quarts (39 L) of automatic transmission fluid through the filler tube. Check and adjust oil level.
FIGURE 23: AIR PRESSURE REGULATOR (TYPICAL)
07037
Caution: Do not overfill the transmission.
Overfilling can cause oil aeration (milky appearance) and overheating. If overfilling occurs, drain oil as required to bring it to the proper level.
07 - 20
Section 07: TRANSMISSION
9. ALLISON TRANSMISSION PRINCIPLES OF OPERATION
Refer to "Allison Transmission, MD Series, Principles of Operation, SA 2454".
10. TROUBLESHOOTING
10.1 EATON AUTOMATIC TRANSMISSION
Refer to ‘’Eaton Fuller’’ Troubleshooting Guide TRTS-0062 annexed at the end of this section.
Fault code retrieval and clearing
Retrieve AutoShift fault codes by enabling the system’s self-diagnostic mode or using a PC-based service tool, such as the Service Ranger:
• Place the transmission in neutral;
• Apply the parking brakes;
• Turn the ignition key to ON but do not start the engine. If the engine is already running, you may still retrieve codes, but do not engage the starter if the engine stalls;
• Retrieve codes :
To retrieve active codes, start with the key/lever in the ON position. Turn the key/lever
OFF and ON two times within five seconds ending with the key/lever in the ON position.
After five seconds, the service light begins flashing two-digit fault codes. If no codes are active, the service light will flash code 25 (no codes).
Observe the sequence of flashes on the service light and record the codes. A one to two second pause separates each stored code and the sequence automatically repeats after all the codes have been flashed.
To retrieve inactive (intermittent) codes, start with the key/lever in the ON position. Turn the key/lever OFF and ON four times within five seconds ending with the key/lever in the
ON position.
After five seconds, the service light begins flashing two-digit fault codes. If no codes are active, the service light will flash code 25 (no codes).
Observe the sequence of flashes on the service light and record the codes. A one to two second pause separates each stored code and the sequence automatically repeats after all the codes have been flashed.
• Clearing Fault Codes :
The following procedure clears all inactive codes from the ECU’s memory (active fault codes are automatically cleared when the fault has been corrected).
Note: PC-based tools such as Service Ranger can be used to clear codes.
To clear inactive codes, start with the key/lever in the ON position. Turn the key/lever
OFF and ON six times within five seconds ending with the key/lever in the ON position. If the codes have been successfully cleared, the service light will come on and stay on for five seconds.
Turn the key/lever to the OFF position and allow the system to power down.
07 - 21
Section 07: TRANSMISSION
• Observe the sequence of flashes on the indicator lights and record the codes. A one or two second pause separates each stored code and the sequence automatically repeats after all codes have been flashed.
Refer to Eaton Fuller Troubleshooting Guide (TRTS-0062).
Eaton Fuller Automatic Transmission Fault Codes
Code Description
11 Shift Control
12 Transmission ECU
16
Eaton proprietary link
(EPL)
41
42
Range failed to engage
Splitter Failed to Engage
17 Start enable relay Coil 43 Range Solenoid Valve
21 Interrupt Solenoid Coil 44 Inertia brake solenoid coil
22 Lockup/Bypass
Solenoid Coil
51 Rail select sensor
24 Hydraulic System Fault 52 Gear select sensor
32
Switched System
Voltage
33 Battery voltage supply
Code Description
35 J-1939 Data Link
56
57
Input shaft speed sensor
Main shaft speed sensor
Code Description
58 Output shaft speed sensor
61 Rail select motor
63
65 Logic Power
71 Stuck engaged
72 Failed to select rail
73
74
83
Gear select motor
Failed to engage gear
Failed to synchronize
Shift lever missing
07 - 22
Section 07: TRANSMISSION
10.2 ALLISON AUTOMATIC TRANSMISSION
Refer to “Allison Transmission, MD Series,
Troubleshooting Manual, SA 2158A”.
10.2.1 WTEC/Electronic Control Unit
The ’’World’’ automatic transmission has a new
Electronic Control Unit (ECU) which involves specific diagnostic incident codes. The ECU transmission unit is located in the coach front service compartment.
FIGURE 24: WTEC / ELECTRONIC CONTROL UNIT 07039
WTEC/ECU Replacement
The automatic transmission ECU is a nonserviceable electronic device. When it fails, it must be replaced using the following procedure:
- open the coach front service compartment in order to get access to the ECU;
remove the electrical cable connectors;
unscrew the WTEC/ECU unit;
replace by reversing the procedure.
Caution: Place the battery master switch to the
‘’OFF’’ position.
10.2.2 WTEC/Troubleshooting
For complete information about
WTEC/Troubleshooting, refer to ‘’Allison
Transmission, MD Series, Troubleshooting
Manual, SA2978’’ March 1997, pages D-9 and D-
10.2.3 Diagnostic Code Memory
Diagnostic codes are logged in a list in memory
(sometimes referred to as the queue), positioning the most recently occurring code first and containing up to five codes. The codes contained in the list have the information recorded as shown in the chart below. Access to the code list position, main code, sub code and active indicator is available through either the shifter display or the Pro-Link Diagnostic Data Reader (DDR).
Access to the ignition cycle counter and event counter is obtained through the DDR only.
Code
List
Position
Main
Code
Sub
Code
Active
Indicator
Ignition
Cycle
Counter
Event
Counter d1 21 12 YES 00 10 d2 41 12 YES 00 04 d3 23 12 NO 08 02 d4 34 12 NO 13 01 d5 56 11 NO 22 02
Displayed on shifter display and DDR YES=
ACTIVE=
"MODE ON"
Ignition cycle counter and event counter are not available on shifter display
Note: All information is available with a diagnostic tool (DDR).
The following paragraphs define the different parts of the code list. Code List Position
07 - 23
Section 07: TRANSMISSION
The position (1 through 5) which a code occupies in the code list in memory. Positions are shown as "d1" (Diagnostic Code #1) through "d5."
Main Code
The general condition or area of fault detected by
ECU.
Sub Code
The specific area or condition under the main code in which the condition was detected.
Active Indicator
Will be turned "On" when a fault condition is active (shifter will display "MODE ON" or the DDR will display "YES"). Will be set to "Off" when conditions exist to indicate fault condition is gone.
Ignition Cycle Counter
Used to clear diagnostic codes that are inactive from the code list in memory. A counter is incremented each time a normal ECU power down occurs following clearing of the Active
Indicator. A code will be cleared from the list when the counter exceeds 25.
Event Counter
Used to count the number of occurrences of a diagnostic code that occurs prior to the incident being cleared from the code list. The most recent code will be in position "d1". If the most recent code is one which is already in the code list, that code will be moved to position "d1", the Active
Indicator will be turned "On" (shifter will display
"MODE ON" or the DDR will display "YES"), the
Ignition Cycle Counter is cleared and "1" is added to the Event Counter.
07 - 24
Clearing the Active Indicator and code
Records from the Code List in Memory
If the conditions causing a diagnostic code to be set are cleared, the Active Indicator can be manually cleared by holding the "MODE" button down continuously for 3 seconds until a tone is heard from the shifter.
To clear code records from the list, hold the
"MODE" button down continuously for ten seconds until a second tone sounds. All diagnostic records in the list that are not active will then be cleared and the remaining records will be moved up the list.
Code Reading and Code Clearing Procedures
Diagnostic codes can be read and cleared by two methods: by using the Pro-Link 9000 DDR plugged in the receptacle located on L.H. lateral console (Shells)/L.H. side control panel
(Coaches) or by using the shifter display. The use of the Pro-Link 9000 DDR is described in the instruction manual supplied with each tool. The method for reading and clearing codes described in this section refers only to entering of the
Diagnostic Display Mode by the proper button selection.
The Diagnostic Display Mode may be entered for viewing of codes at any speed. Codes can only be cleared when the output speed = 0 and no output speed sensor failure is active.
The following descriptions explain how to use the shifter to read and clear codes.
1. Enter the diagnostic display mode by pressing the " " and " " (upshift and downshift arrows) buttons at the same time on the pushbutton shifter.
Note: If a "DO NOT SHIFT" condition is present at this time, the lever should be in the same position as it was at the time of code detection. If not, this shifter tone will sound continuously.
Note : If an Oil Level Sensor (OLS) is present, the oil level will be displayed first. Diagnostic code display is achieved by depressing the UPSHIFT and DOWNSHIFT arrows or display MODE button a second time.
2. Read the first code in the first of five code positions on the digital display of the shifter.
For example, we will read code 25 11 in the first position. The display will change every two seconds as follows: a. Code list position --"d1"; b. Main code --"25"; c. Sub code --"11"; and d. Display will repeat cycle of a., b. and c, above.
3. Press the "MODE" button momentarily to view the second position (d2) in the same way as 2. above.
4. To view the third, fourth and fifth positions
(d3, d4 and d5), momentarily press the
"MODE" button as explained above.
5. Pressing the "MODE" button momentarily after the fifth position is displayed will cause the sequence of code positions to start over with the first position.
6. Any code that is active will be indicated by the
"MODE ON" indicator (Active Indicator) being turned on while in that code position (while in the normal operation).
7. Any code position in the list which does not have a diagnostic code logged will display "- -
" for both the main and sub code displays. All positions after a code codes.
1. Clearing of the active indicator is automatically done at ECU power down on all but code 69 34.
2. Some codes will clear the active indicator automatically when the condition causing the code is no longer detected by the ECU (see
Diagnostic Code List and Description, page 7
- 22).
3. Manual clearing is possible while in the diagnostic display mode and after the condition causing the code is corrected
(output speed must be zero). a. To clear all active indicators, hold the
"MODE" button down continuously for 3 seconds until the shifter tone sounds for
0.5 seconds. b. Release the "MODE" button to return to normal operating mode. If the condition
Section 07: TRANSMISSION causing the code was not active at the time, the active indicator will turn off.
Caution: If clearing a code while locked in a
Forward or Reverse position (fail-to-range), the transmission will still be in Drive or Reverse when the clearing procedure is completed. Neutral must be selected manually.
Exiting the Diagnostic Display Mode
The diagnostic display mode can be exited by any of the following procedures:
1. Press the " " and " " (upshift and downshift) buttons at the same time on the pushbutton shifter.
2. Press any range button, "D", "N" or "R", on the pushbutton shifter (the shift will be commanded if it is not inhibited by an active code).
3. Do nothing and wait until the calibrated time
(approximately 10 minutes) has passed and the system automatically returns to the normal operating mode.
4. Turn off power to the ECU (turn off the vehicle at the ignition switch).
5. After the clearing of a code, the active indicator procedure described above has been performed.
Clearing Records from the Code List in
Memory
If the requirements for Manual Clearing the Active
Indicator have been satisfied, and the "MODE" button is held down continuously for ten seconds while in the display mode until a tone sounds, then all diagnostic records in the code list that are not active will be cleared and the remaining records will be moved up in the code list.
Abbreviations found in the Code Chart
The following responses are used throughout the following chart to command safe operation when diagnostic codes are set.
1. DNS ( D o N ot S hift) Response a. Turn off lockup clutch and inhibit lockup operation. b. Inhibit all shifts. c. Turn on the DO NOT SHIFT light.
07 - 25
Section 07: TRANSMISSION d. Pulse the tone generator for 8 seconds when the condition is first detected. e. Blank the select digit in the display.
f. Ignore any range selection inputs and disable the button feedback tone for the pushbutton shifter.
2. SOL OFF ( Sol enoid Off ) Response
All solenoids are commanded off (turning solenoids "A" and "B" off electrically causes them to be on hydraulically).
Diagnostic code list and description
MAIN
CODE
12
SUB
CODE
12
DESCRIPTION
Oil level, low
12
13
13
23
12
13
Oil level, high
ECU input voltage, low
ECU input voltage, medium low
3.
4. NNC ( N eutral N o C lutches) Response
13 23 ECU input voltage, high
23
23
23
14
14
21
24
12
23
12
12
Oil level sensor, low
Oil level sensor, high
Throttle position sensor, low
21
22
23
15
Throttle position sensor, high
Engine speed sensor reasonableness test
Turbine speed sensor reasonableness test
22 16
23 12
Output speed sensor reasonableness or rapid decel test
Primary Shifter or RSI Link Fault
13
14
15
Primary Shifter Mode Function Fault
Secondary Shifter or RSI Link Fault
Secondary Shifter Mode Function
Fault
Sump oil temperature, cold
07 - 26
RPR ( R
When the ratio or C3 pressure switch tests associated with a shift are not passed, the
ECU commands the same range as commanded at the beginning of the shift.
When certain ratio or C3 pressure switch tests are not passed, the ECU commands a neutral condition with no clutches applied.
DO NOT
SHIFT
LIGHT
No
No
Yes
No
Yes
No
No
No
No
No
INHIBITED
OPERATION
DESCRIPTION
No upshift above a calibration range
No upshift above a calibration range
DNS, SOL OFF
(Hydraulic default)
None: Shift adaptive feature will not function.
DNS, SOL OFF
(Hydraulic default)
None
None
Use Throttle default value
Use Throttle default value
Use default engine speed
Yes DNS, Lock in current range
Yes
No
No
No
No
Yes eturn to P revious R ange) Response
DNS, Lock in current range
Hold in last valid direction
Mode change not permitted
Hold in last valid direction
Mode change not permitted
DNS
Section 07: TRANSMISSION
32
33
33
34
MAIN
CODE
24
SUB
CODE
23
DESCRIPTION
Sump oil temperature, hot
25
25
25
25
25
25
25
25
32
00
11
22
33
44
55
66
77
00
Output speed reasonableness test, detected at 0 speed, (L)
Output speed reasonableness test, detected at 0 speed, (1st)
Output speed reasonableness test, detected at 0 speed 2nd
Output speed reasonableness test, detected at 0 speed, 3rd
Output speed reasonableness test, detected at 0 speed, 4th
Output speed reasonableness test, detected at 0 speed, 5th
Output speed reasonableness test, detected at 0 speed, 6th
Output speed reasonableness test, detected at 0 speed, R
C3 pressure switch open, L range
32
32
33
55
C3 pressure switch open, 3rd range
C3 pressure switch open, 5th range
34
34
34
77
12
23
12
13
14
15
C3 pressure switch open, R range
Sump oil temperature sensor, low
Sump oil temperature sensor, high
EEPROM, factory cal. compatibility number wrong
EEPROM, factory calibration block checksum
EEPROM, Power Off Block checksum
EEPROM, Diagnostic Queue Block
07 - 27
DO NOT
SHIFT
LIGHT
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Yes
Yes
Yes
Yes
INHIBITED
OPERATION
DESCRIPTION
No upshifts above a calibration range
DNS, Lock in current range (L)
DNS, Lock in current range (1st)
DNS, Lock in current range (2nd)
DNS, Lock in current range (3rd)
DNS, Lock in current range (4th)
DNS, Lock in current range (5th)
DNS, Lock in current range (6th)
DNS, Lock in current range (R)
DNS, Lock in current range (L)
DNS, Lock in current range (3rd)
DNS, Lock in current range (5th)
DNS, Lock in current range (R)
Use default value of
200
ø
F (93
ø
C)
Use default value of
200 ø F (93 ø C)
DNS, SOL OFF
(Hydraulic default)
DNS, SOL OFF
(Hydraulic default)
Use previous location, or factory calibration and reset adaptive
Use previous location,
Section 07: TRANSMISSION
MAIN
CODE
SUB
CODE
DESCRIPTION
34 16
Checksum
EEPROM, Real Time Block
Checksum
Power
(Code set after power restored)
35 16 Real Time EEPROM Write
Interruption
36 00 Hardware/Software not compatible
41
41
12
13
41
41
41
41
41
41
41
41
42
42
42
14
15
16
21
22
24
25
26
12
13
14
Open or short to ground, A solenoid circuit
Open or short to ground, B solenoid circuit
Open or short to ground,
C solenoid circuit
Open or short to ground,
D solenoid circuit
Open or short to ground,
E solenoid circuit
Open or short to ground,
F solenoid circuit
Open or short to ground,
G solenoid circuit
Open or short to ground,
H solenoid circuit
Open or short to ground,
J solenoid circuit
Open or short to ground,
K solenoid circuit
Open or short to ground,
N solenoid circuit
Short to battery, A solenoid circuit
Short to battery, B solenoid circuit
Short to battery, C solenoid circuit
07 - 28
DO NOT
SHIFT
LIGHT
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
INHIBITED
OPERATION
DESCRIPTION or clear diagnostic queue
DNS, SOL OFF
(Hydraulic default)
NONE (Hydraulic default during interruption)
DNS, SOL OFF
(Hydraulic default)
DNS, SOL OFF
(Hydraulic default)
DNS, SOL OFF
(Hydraulic default)
DNS, SOL OFF
(Hydraulic default)
DNS. SOL OFF
(Hydraulic default)
DNS, SOL OFF
(Hydraulic default)
DNS, SOL OFF
(Hydraulic default)
Yes
No
No
No
Yes
Yes
Yes
DNS, SOL OFF
(Hydraulic default) differential lock inhibited
Low and 1st inhibited
K solenoid operation inhibited
Low and 1st inhibited
DNS, Lock in a range
DNS, Lock in a range
DNS, Lock in a range
MAIN
CODE
42
42
42
42
42
42
42
42
43
43
43
44
44
44
44
44
44
44
44
SUB
CODE
15
16
21
22
23
24
25
26
21
25
26
12
13
14
15
16
21
22
23
DESCRIPTION
Short to battery, D solenoid circuit
Short to battery, E solenoid circuit
Short to battery, F solenoid circuit
Short to battery, G solenoid circuit
Short to battery, H solenoid circuit
Short to battery, J solenoid circuit
Short to battery, K solenoid circuit
Short to battery, N solenoid circuit
Low side driver,
F solenoid circuit
Low side driver,
K solenoid circuit
Low side driver,
N solenoid circuit
Short to ground, A solenoid circuit
Short to ground, B solenoid circuit
Short to ground, C solenoid circuit
Short to ground, D solenoid circuit
Short to ground, E solenoid circuit
Short to ground, F solenoid circuit
Short to ground, G solenoid circuit
Short to ground, H
07 - 29
Section 07: TRANSMISSION
DO NOT
SHIFT
LIGHT
Yes
INHIBITED
OPERATION
DESCRIPTION
DNS, Lock in a range
Yes DNS, Lock in a range
Yes DNS, Lock in a range allowed, differential lock inhibited
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
No
Low and 1st inhibited
K solenoid operation inhibited
Low and 1st inhibited
K solenoid operation inhibited
Low and 1st inhibited
DNS, SOL OFF
(Hydraulic default)
DNS, SOL OFF
(Hydraulic default)
DNS, SOL OFF
(Hydraulic default)
DNS, SOL OFF
(Hydraulic default)
DNS, SOL OFF
(Hydraulic default)
DNS, SOL OFF
(Hydraulic default)
Retarder allowed.
Section 07: TRANSMISSION
MAIN
CODE
44
44
44
45
45
45
45
45
45
45
45
45
45
45
51
51
51
51
SUB
CODE
24
25
26
12
13
14
15
16
21
22
23
24
25
26
10
12
21
23
DESCRIPTION solenoid circuit
Short to ground, J solenoid circuit
Short to ground, K solenoid circuit
Short to ground, N solenoid circuit
Open circuit, A solenoid circuit
Open circuit, B solenoid circuit
Open circuit, C solenoid circuit
Open circuit, D solenoid circuit
Open circuit, E solenoid circuit
Open circuit, F solenoid circuit
Open circuit, G solenoid circuit
Open circuit, H solenoid circuit
Open circuit, J solenoid circuit
Open circuit, K solenoid circuit
Open circuit, N solenoid circuit
Offgoing ratio test (during shift),
1 to L
Offgoing ratio test (during shift),
1 to 2
Offgoing ratio test (during shift),
2 to 1
Offgoing ratio test (during shift),
07 - 30
DO NOT
SHIFT
LIGHT
No
INHIBITED
OPERATION
DESCRIPTION differential lock inhibited
Low and 1st inhibited
No
No
Yes
Yes
Yes
Yes
Yes
K solenoid operation inhibited
Low and 1st inhibited
DNS, SOL OFF
(Hydraulic default)
DNS, SOL OFF
(Hydraulic default)
DNS, SOL OFF
(Hydraulic default)
DNS, SOL OFF
(Hydraulic default)
DNS, SOL OFF
(Hydraulic default)
Yes DNS, SOL OFF
(Hydraulic default) allowed differential lock inhibited
No Low and 1st inhibited
No
No
Yes
Yes
K solenoid operation inhibited
Low and 1st inhibited
Low and 1st inhibited
DNS, RPR
MAIN
CODE
51
51
51
52
52
52
52
52
52
52
52
52
52
52
53
53
53
SUB
CODE
43
45
65
01
08
32
34
54
56
71
72
78
79
99
08
18
28
DESCRIPTION
2 to 3
Offgoing ratio test (during shift),
4 to 3
Offgoing ratio test (during shift),
4 to 5
Offgoing ratio test (during shift),
6 to 5
Offgoing C3PS test (during shift),
L to 1
Offgoing C3PS test (during shift),
L to N1
Offgoing C3PS test (during shift),
3 to 2
Offgoing C3PS test (during shift),
3 to 4
Offgoing C3PS test (during shift),
5 to 4
Offgoing C3PS test (during shift),
5 to 6
Offgoing C3PS test (during shift),
R to 1
Offgoing C3PS test (during shift),
R to 2
Offgoing C3PS test (during shift),
R to N1
Offgoing C3PS test (during shift),
R to 2 (R to NNC to 2)
Offgoing C3PS test (during shift),
N3 to N2
Offgoing speed test (during shift),
L to N1
Offgoing speed test (during shift),
1 to N1
Offgoing speed test (during shift),
2 to N1
07 - 31
DO NOT
SHIFT
LIGHT
Yes
Section 07: TRANSMISSION
INHIBITED
OPERATION
DESCRIPTION
DNS, NNC
Section 07: TRANSMISSION
MAIN
CODE
53
53
53
53
53
53
53
53
53
53
53
54
54
54
54
54
54
54
SUB
CODE
29
38
39
48
49
58
59
68
69
78
99
01
07
10
12
17
21
23
DESCRIPTION
Offgoing speed test (during shift),
2 to N2
Offgoing speed test (during shift),
3 to N1
Offgoing speed test (during shift),
3 to N3
Offgoing speed test (during shift),
4 to N1
Offgoing speed test (during shift),
4 to N3
Offgoing speed test (during shift),
5 to N1
Offgoing speed test (during shift),
5 to N3
Offgoing speed test (during shift),
6 to N1
Offgoing speed test (during shift),
6 to N4
Offgoing speed test (during shift),
R to N1
Offgoing speed test (during shift),
N2 to N3 or N3 to N2
Oncoming ratio test (after shift),
L to 1
Oncoming ratio test (after shift),
L to R
Oncoming ratio test (after shift),
1 to L
Oncoming ratio test (after shift),
1 to 2
Oncoming ratio test (after shift),
1 to R
Oncoming ratio test (after shift),
2 to 1
Oncoming ratio test (after shift),
07 - 32
DO NOT
SHIFT
LIGHT
Yes
INHIBITED
OPERATION
DESCRIPTION
DNS, RPR
MAIN
CODE
54
54
54
54
54
54
54
54
54
54
54
54
54
54
54
54
54
SUB
CODE
27
32
34
43
45
54
56
65
70
71
72
80
81
82
83
85
86
DESCRIPTION
2 to 3
Oncoming ratio test (after shift),
2 to R
Oncoming ratio test (after shift),
3 to 2
Oncoming ratio test (after shift),
3 to 4
Oncoming ratio test (after shift),
4 to 3
Oncoming ratio test (after shift),
4 to 5
Oncoming ratio test (after shift),
5 to 4
Oncoming ratio test (after shift),
5 to 6
Oncoming ratio test (after shift),
6 to 5
Oncoming ratio test (after shift),
R to L
Oncoming ratio test (after shift),
R to 1
Oncoming ratio test (after shift),
R to 2
Oncoming ratio test (after shift),
N1 to L
Oncoming ratio test (after shift),
N1 to 1
Oncoming ratio test (after shift),
N1 to 2
Oncoming ratio test (after shift),
N1 to 3
Oncoming ratio test (after shift),
N1 to 5
Oncoming ratio test (after shift),
Nl to 6
07 - 33
DO NOT
SHIFT
LIGHT
Section 07: TRANSMISSION
INHIBITED
OPERATION
DESCRIPTION
Yes DNS, RPR or SOL
OFF (Hydraulic default)
Yes DNS,RPR
Yes DNS,RPR
Yes DNS,RPR
Yes DNS,NNC
Yes DNS,NNC
Yes DNS,NNC
Yes DNS,RPR
Yes DNS,RPR
Yes DNS,RPR
Yes DNS,RPR
Yes DNS,RPR
56
56
56
56
56
56
56
Section 07: TRANSMISSION
MAIN
CODE
54
54
54
54
54
54
54
55
55
55
55
55
56
SUB
CODE
92
92
92
93
95
96
97
17
27
80
87
97
00
DESCRIPTION
Oncoming ratio test (after shift),
R to 2 (R to NNC to 2)
Oncoming ratio test (after shift),
N1 to 2 (N1 to NNC to 2)
Oncoming ratio test (after shift),
N2 to 2
Oncoming ratio test (after shift),
N3 to 3
Oncoming ratio test (after shift),
N3 to 5
Oncoming ratio test (after shift),
N4 to 6
Oncoming ratio test (after shift),
2 to R (2 to NNC to R)
Oncoming C3PS test (after shift),
1 to R
Oncoming C3PS test (after shift),
2 to R
Oncoming C3PS test (after shift),
N1 to L
Oncoming C3PS test (after shift),
N1 to R
Oncoming C3PS test (after shift),
2 to R or NVL to R (2 to NNC to R)
Range verification test, L
11
22
33
44
55
66
77
Range verification test, 1st
Range verification test, 2nd
Range verification test, 3rd
Range verification test, 4th
Range verification test, 5th
Range verification test, 6th
Range verification test, R
07 - 34
DO NOT
SHIFT
LIGHT
INHIBITED
OPERATION
DESCRIPTION
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
DNS, 1st, Low, or
SOL OFF (Low)
DNS, 6th
DNS, 6th or 5th
DNS, 5th or SOL
DNS, 3rd or 5th
DNS, SOL OFF (5th) or 3rd
DNS, 5th, 3rd, or
SOL OFF (3rd)
DNS, N2 or N3
Section 07: TRANSMISSION
MAIN
CODE
57
57
57
57
57
57
61
62
62
63
64
64
65
66
69
69
69
69
69
69
69
69
69
SUB
CODE
11
22
44
66
88
99
00
12
23
00
12
23
00
00
12
DESCRIPTION
Range verification C3PS test, 1st
Range verification C3PS test, 2nd
Range verification C3PS test, 4th
Range verification C3PS test, 6th
Range verification C3PS test, N1
Range verification C3PS test,
N2 or N4
Retarder oil temperature, hot
Retarder oil temperature sensor, low
Retarder oil temperature sensor, high
Special function input
Retarder modulation request sensor, low
Retarder modulation request sensor, high
Engine rating too high
Serial communications interface fault
ECU, A solenoid driver open
DO NOT
SHIFT
LIGHT
Yes
Yes
Yes
Yes
Yes
INHIBITED
OPERATION
DESCRIPTION
DNS, SOL OFF (3rd)
DNS, 3rd
DNS, 5th or SOL OFF (3rd)
SOL OFF (5th), DNS
DNS, N3
No
No
Yes
No
Yes
None
None
No None
No
No
No
Depends on special function
Retarder operation inhibited
Retarder operation inhibited
13
14
15
16
21
22
23
24
ECU, B solenoid driver open
ECU, C solenoid driver open
ECU, D solenoid driver open
ECU, E solenoid driver open
ECU, F solenoid driver open
ECU, G solenoid driver open
ECU, H solenoid driver open
ECU, J solenoid driver open
07 - 35
Yes
Yes
Yes
Yes
No
Yes
No
No
DNS
Use default throttle values
DNS, SOL OFF
(hydraulic default)
DNS, SOL OFF
(hydraulic default)
DNS, SOL OFF
(hydraulic default)
DNS, SOL OFF
(hydraulic default)
DNS, SOL OFF
(hydraulic default)
Lock-up inhibited
DNS, SOL OFF
(Hydraulic default)
Retarder allowed, differential lock inhibited
Low and 1 st inhibited
Section 07: TRANSMISSION
MAIN
CODE
69
69
69
SUB
CODE
25
26
32
DESCRIPTION
ECU, K solenoid driver open
ECU, N solenoid driver open
ECU, SPI communications link fault
69 33
69 34
ECU, Central Operating Processor
(COP) time-out
ECU, EEPROM write time-out
69
69
69
0
70
70
35
36
41
35
35
35
ECU, EEPROM checksum
ECU, RAM self test
ECU, I/O ASIC addressing test
Software, minor loop overrun
Software, illegal write to access
$0000
Software, major loop overrun
DO NOT
SHIFT
LIGHT
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
INHIBITED
OPERATION
DESCRIPTION
K solenoid operation inhibited
Low and 1st inhibited
Hold in last valid direction
Reset ECU, Shutdown ECU on 2nd occurrence (power loss: hydraulic defaults)
DNS, SOL OFF
(Hydraulic default)
Induce COP time-out
(reset ECU)
Induce COP time-out
(reset ECU)
Induce COP time-out
(reset ECU)
Induce COP time-out
(reset ECU)
Induce COP time-out
(reset ECU)
Induce COP time-out
(reset ECU)
07 - 36
Section 07: TRANSMISSION
11. SPECIFICATIONS
EATON AUTOMATIC TRANSMISSION
Make ....................................................................................................................................Eaton Fuller Autoshift
Model .......................................................................................................................................... TO-14607B-AST
Ratio:
Overall.........................................................................................................................................................12.35:1
Reverse ........................................................................................................................................................8.99:1
1st .................................................................................................................................................................9.24:1
2nd ................................................................................................................................................................5.35:1
3rd.................................................................................................................................................................3.22:1
4th .................................................................................................................................................................2.04:1
5th .................................................................................................................................................................1.37:1
6th .................................................................................................................................................................1.00:1
7th .................................................................................................................................................................0.75:1
Torque converter stall ratio ............................................................................................................................2.2:1
Fluid:
Type ........................................................................................................................................................ Dexron III
Capacity...............................................................................................................................89 US pints (42 liters)
Torque Capacity .................................................................................................................1450 lbf•ft (1964 N•m)
ALLISON AUTOMATIC TRANSMISSION WITH OR WITHOUT RETARDER
XL2 Buses
Gross input power (maximum)....................................................................................................450 hp (335 kW)
Gross input torque (maximum) ..........................................................................................1460 lbf•ft (1978 N•m)
Rated input speed (minimum-maximum) .....................................................................................1600-2300 rpm
XL2 MTH
Gross input power (maximum)....................................................................................................525 hp (391 kW)
Gross input torque (maximum) ..........................................................................................1550 lbf•ft (2102 N•m)
Rated input speed (minimum-maximum) .....................................................................................1600-2300 rpm
Mounting:
Engine....................................................................................................SAE #1 flywheel housing, flex disk drive
Torque converter:
Type ........................................................................................................... One stage, three element, polyphase
Stall torque ratio .................................................... TC 521-2.4;TC 531-2.3;TC 541-1.9;TC 551-1.8;TC 561-1.6
Lockup clutch with torsional damper ......................................................................................... Integral/standard
Gearing:
Type ................................................................................................. Patented, constant mesh, helical, planetary
Ratio:
07 - 37
Section 07: TRANSMISSION
First ...............................................................................................................................................................3.51:1
Second..........................................................................................................................................................1.91:1
Third..............................................................................................................................................................1.43:1
Fourth............................................................................................................................................................1.00:1
Fifth ...............................................................................................................................................................0.74:1
Sixth ..............................................................................................................................................................0.64:1
Reverse ........................................................................................................................................................4.80:1
Ratio coverage:
6 speed .........................................................................................................................................................5.48:1
* Gear ratios do not include torque converter multiplication.
Oil System:
Oil type............................................................................................ DEXRON-IIE, DEXRON III OR TRANSYND
Capacity (excluding external circuits) ......................................................................Initial fill 47 US qts (45 liters)
Oil change.............................................................................................................................. 37 US qts (39 liters)
Oil Filters:
Make ..................................................................................................................................... Allison Transmission
Type ...................................................................................................................................... Disposable cartridge
Supplier number .....................................................................................................................................29503829
Prévost number ........................................................................................................................................ 57-1687
07 - 38
SECTION 09: PROPELLER SHAFT
CONTENTS
1. PROPELLER SHAFT.......................................................................................................................09-2
1.1 DESCRIPTION ..........................................................................................................................09-2
2. REMOVAL, DISASSEMBLY, REASSEMBLY AND INSTALLATION ............................................09-2
3.1 CLEANING AND INSPECTION.................................................................................................09-3
3.2 LUBRICATION...........................................................................................................................09-3
4. EXPLANATION OF COMMON DAMAGES.....................................................................................09-3
5. TROUBLESHOOTING .....................................................................................................................09-3
6. SPECIFICATIONS............................................................................................................................09-3
ILLUSTRATIONS
F IGURE 1: PROPELLER SHAFT ASSEMBLY .....................................................................................................09-2
09 - 1
Section 09: PROPELLER SHAFT
1. PROPELLER
1.1 DESCRIPTION
The propeller shaft transmits power from the transmission to the differential (Fig. 1). Depending on the vehicle's transmission type, different lengths of propeller shafts are available. Refer to paragraph "6. SPECIFICATIONS" at the end of this section for details. All propeller shafts are
"Dana 1810 " type with tubular shafts. They are provided with two heavy-duty universal joints (Fig.
1).
The propeller shaft has a full round end yoke at each end. The tube yoke is connected to the differential by a full round end yoke with four needle bearings.
The other extremity (slip yoke assembly) is connected to the transmission by a half round end yoke with two needle bearings.
Furthermore, a slip joint on the propeller shaft compensates for variations in distance between the transmission and the differential, or between the output retarder (optional on the automatic transmission) and differential.
The rise and fall of the drive axle bring about these variations as the vehicle passes over uneven surfaces. The slip joint also eases removal of the transmission or the drive axle.
DISASSEMBLY,
REASSEMBLY AND INSTALLATION
Refer to "SPICER UNIVERSAL JOINTS AND
DRIVESHAFTS" annexed to this section, under headings "Heavy Duty - removal, disassembly, reassembly and installation".
Where applicable:
• Remove or install propeller shaft safety guard.
• Screw bolts to the specified torque (Fig. 1).
Note: Disregard the procedure on "Lock straps" mentioned in the "Spicer Universal Joints and
Driveshafts Manual".
ASSEMBLY
09002
09 - 2
3. CLEANING, INSPECTION AND
LUBRICATION
3.1 CLEANING AND INSPECTION
Thoroughly clean grease from bearings, journal, lubricating grease fittings and other parts. Needle bearing assemblies may be soaked in a cleaning solution to soften hard grease particles. It is extremely important that bearing assemblies be absolutely clean and blown out with compressed air, since small particles of dirt or grit can cause rapid bearing wear. Do not attempt to disassemble needle bearings.
Bearing journal areas should be inspected for roughness or grooving. If light honing does not remove roughness, the entire bearing assembly should be replaced. Excessive wear of the needle bearing is indicated if the needles drop out of the retainer, or if marks are present on the journal bearing surface. In such case, replace bearing assembly. Finally, inspect yokes for cracks, wear or distortion.
Note: Repair kits are available for overhaul of the propeller shaft assembly. Refer to the paragraph
"6. Specifications" of this section.
3.2 LUBRICATION
Lubricate propeller shaft universal joints and slip yoke periodically, every 6,250 miles (10 000 km) or twice a year, whichever comes first. Apply grease gun pressure to the lube fitting. Use a good quality lithium-base grease such as: NLGI
No.2 (suitable for most temperatures) or NLGI
No.1 (suitable for extremely low temperatures).
Refer to "Spicer Universal Joints and Driveshafts,
Service Manual", under heading, "Inspection and
Lubrication". See lubrication procedures for Ujoints and lubrication for slip splines.
Note: Do not assume that bearing cavities have been filled with new grease unless it has expelled around all seals.
6. SPECIFICATIONS
09 - 3
Section 09: PROPELLER SHAFT
4. EXPLANATION OF COMMON DAMAGES
1. Cracks: Stress lines due to metal fatigue.
Severe and numerous cracks will weaken the metal until it breaks.
2. Galling: Scraping off of metal or metal displacement due to friction between surfaces.
This is commonly found on trunnion ends.
3. Spalling (surface fatigue): Breaking off of chips, scales, or flakes of metal due to fatigue rather than wear. It is usually found on splines and U-joint bearings.
4. Pitting: Small pits or craters in metal surfaces due to corrosion. If excessive, pitting can lead to surface wear and eventual failure.
5. Brinelling: Surface wear failure due to the wearing of grooves in metal. It is often caused by improper installation procedures. Do not confuse the polishing of a surface (false brinelling), where no structural damage occurs, with actual brinelling.
Overloading: load greater than the component can stand. A structural overload may cause propeller shaft tubing to twist under strain or it may cause cracks or breaks in U-joints and spline plugs.
5. TROUBLESHOOTING
Refer to "Spicer Service Manual - Universal
Joints and Driveshafts" under heading
"Troubleshooting".
Section 09: PROPELLER SHAFT
PROPELLER SHAFT
XL2-40 COACH
Vehicles equipped with a World Transmission
Make ........................................................................................................................................... Hayes-Dana Inc.
Series..............................................................................................................................................................1810
Supplier number ..................................................................................................................................... 819299-1
Prevost number ..........................................................................................................................................580075
Vehicles equipped with and Eaton Fuller Automatic Transmission
Make ........................................................................................................................................... Hayes-Dana Inc.
Series..............................................................................................................................................................1810
Supplier number ...............................................................................................................................................N/A
Prevost number ................................................................................................................................................N/A
XL2-45 COACH AND M-45 MOTORHOME
Vehicles equipped with a World Transmission
Make ........................................................................................................................................... Hayes-Dana Inc.
Series..............................................................................................................................................................1810
Supplier number ............................................................................................................................... 819325-2200
Prevost number ..........................................................................................................................................580070
Vehicles equipped with an Eaton Fuller Automatic Transmission
Make ........................................................................................................................................... Hayes-Dana Inc.
Series..............................................................................................................................................................1810
Supplier number ...............................................................................................................................................N/A
Prevost number ................................................................................................................................................N/A
M-40 AND M-45E MOTORHOME
Make ........................................................................................................................................... Hayes-Dana Inc.
Series..............................................................................................................................................................1810
Supplier number ..................................................................................................................................... 819299-1
Prevost number ..........................................................................................................................................580075
09 - 4
Section 09: PROPELLER SHAFT
Repair kits
Make .......................................................................................................................................... Hayes-Dana Inc.
U-joint kit (tube yoke), Supplier number .................................................................................................... 5-281X
U-joint kit (tube yoke), Prevost number .....................................................................................................580043
U-joint kit (slip yoke), Supplier number...................................................................................................... 5-510X
U-joint kit (slip yoke), Prevost number.......................................................................................................580062
Cap and bolt kit, bolt torque 115-135 lbf•ft (156-183 N•m), Supplier number ....................................6.5-70-18X
Cap and bolt kit, bolt torque 115-135 lbf•ft (156-183 N•m), Prevost number ...........................................580063
Bolts kit, bolt torque 38-48 lbf•ft (52-65 N•m), Supplier number ............................................................ 6-73-209
Bolts kit, bolt torque 38-48 lbf•ft (52-65 N•m), Prevost number ................................................................580071
Half Round End Yoke
Make ............................................................................................................................................ Hayes-Dana Inc
(6 speed), Supplier number ..............................................................................................................6.5-4-3021-1
(6 speed), Prevost number ........................................................................................................................580072
Make .................................................................................................................................................. Dana-Spicer
(7 speed), Supplier number ..............................................................................................................6.5-4-3821-1
(7 speed), Prevost number ........................................................................................................................571690
Note: U-joint kits will come equipped with the serrated bolt and lock patch and will no longer contain a lock strap.
09 - 5
SECTION 10: FRONT AXLE
CONTENTS
1. FRONT AXLE ...................................................................................................................................10-2
1.1 DESCRIPTION ..........................................................................................................................10-2
2. LUBRICATION .................................................................................................................................10-3
3. MAINTENANCE ...............................................................................................................................10-3
3.1 TIE ROD END PLAY ADJUSTMENT.........................................................................................10-3
4.1 REMOVAL .................................................................................................................................10-3
4.2 REPLACEMENT........................................................................................................................10-4
6.1 MINOR FRONT WHEEL ALIGNMENT......................................................................................10-4
6.2 MAJOR FRONT WHEEL ALIGNMENT .....................................................................................10-4
6.3 INSPECTION BEFORE ALIGNMENT .......................................................................................10-5
6.4 TURNING ANGLE ADJUSTMENT ............................................................................................10-5
Turn Adjustment.........................................................................................................10-5
Turn Adjustment .........................................................................................................10-6
6.5 HYDRAULIC STOP ...................................................................................................................10-7
6.6 FRONT WHEEL CAMBER ........................................................................................................10-7
6.6.1 Camber Check ...................................................................................................................10-7
6.7 FRONT AXLE CASTER.............................................................................................................10-7
6.8 FRONT WHEEL TOE-IN............................................................................................................10-8 and Adjustment .................................................................................................10-9
7. TROUBLESHOOTING ...................................................................................................................10-10
8. SPECIFICATIONS..........................................................................................................................10-11
ILLUSTRATIONS
FIGURE 1: FRONT AXLE ASSEMBLY ....................................................................................................10-2
FIGURE 2: TIE ROD END PLAY ADJUSTMENT.....................................................................................10-3
FIGURE 3: CAMBER................................................................................................................................10-7
FIGURE 4: CASTER ................................................................................................................................10-8
FIGURE 5: TOE-IN MEASUREMENTS ...................................................................................................10-8
FIGURE 6: AIR BELLOWS MOUNTING SUPPORT AND AXLE ...........................................................10-11
10 - 1
Section 10: FRONT AXLE
1.1 DESCRIPTION
This front axle is of the ‘’Reverse Elliot’’ type manufactured by Dana Spicer Europe. The front axle consists of a girder section axle bed or beam with stub axles. Each stub axle is carried on a taper king pin, with a steep angle taper roller bearing at its top and a plain phosphor bronze bushing at the bottom. The hub taper roller bearings are of a generous size and adjusted by means of shims, and secured by a special nut and washer. Brakes are manufactured by
KNORR-BREMSE. Steering ball joints with hardened balls and rubbing pads incorporate compression springs which automatically take up any wear.
The tie rod simplifies toe-in adjustment. The maximum turning angle is set through stop screws installed on the inner side of the knuckle.
Steering stabilizer (damper) and steering drag link which are mounted on the front axle are described in Section 14; ‘’Steering’’ of this manual.
FIGURE 1: FRONT AXLE ASSEMBLY
10026
10 - 2
Section 10: FRONT AXLE
2. LUBRICATION
Perform periodic lubrication. Lubrication points of the front axle are shown on the lubrication and servicing chart annexed to Section 24;
‘’Lubrication’’ . Tie rod ends and knuckle pins are provided with grease fittings for pressure lubrication. These grease fittings should be serviced every 6,250 miles (10 000 km) or twice a year whichever comes first. Good quality lithium-base grease NLGI No.1 and 2 are recommended.
3. MAINTENANCE piece fully home (SOLID) locating thrust cup onto ball pin.
Still with tool located on adjuster piece, back off carefully (LEAST AMOUNT) until adjuster piece cotter pin is allowed to pass through body, then remove tool.
Reinstall protective cap.
A periodic inspection of the front axle assembly should be made to check that all bolts are tight, and that no damage and distortion have taken place. Suspension support stud nuts, U-bolt nuts, tie rod arms, steering arm nuts and stop screws should be checked and tightened, as required, to the torque specifications given at the end of this section. Also check the condition of the steering knuckle pins and bushings. In case of excessive looseness, the bushings and pins should be replaced.
FIGURE 2: TIE ROD END PLAY ADJUSTMENT
4. REMOVAL AND REPLACEMENT
10029
The following procedure deals with the removal of the front axle assembly. The method used to support the axle assembly and suspension components during removal and disassembly depends upon local conditions and available equipment.
Any looseness in the steering linkage, under normal steering loads, is sufficient cause to immediately check all pivot points for wear, regardless of accumulated mileage. Steering linkage pivot points should be checked each time the front axle assembly is lubricated. Any looseness can be visually detected while rotating the steering wheel in both directions.
4.1 REMOVAL
1. Raise the vehicle by its jacking points on the body (see Section 18, ‘’Body’’ under heading
16; Vehicle Jacking Points) until vehicle body is approximately 30 inches (760 mm) from the floor. Place jack stands under frame. Remove the wheels (if required, refer to Section 13,
‘’Wheels, Hubs and Tires’’ ).
Steering knuckles, knuckle pins and bushings can be overhauled or replaced without removing the axle from the vehicle. However, if extensive overhaul work is necessary, the axle assembly should be removed.
Caution : Use only the recommended jacking points as outlined in section 18 “BODY”.
Caution: Should removal of a locking device be required when undergoing repairs, disassembly or adjustments, always replace with a new one.
2. Exhaust compressed air from the air supply system by opening the drain valve of each reservoir.
3. Install jacks under axle jacking points to support the axle weight.
3.1 TIE ROD END PLAY ADJUSTMENT
If end play exceeds 0.047” (1.2 mm), readjustment is necessary.
Remove protective cap, using a suitable tool ie: a 1” x 1/8” x 9” long flat bar, tighten adjuster
10 - 3
Warning : To help prevent injury caused by the axle rolling off the jacks, these should be equipped with U-adapters, or similar precautions must be taken.
Section 10: FRONT AXLE
4. Disconnect the steering drag link from the steering arm.
5. Remove the ABS sensors from their location in hubs (if applicable).
6. Disconnect the height control valve link from its support on the axle.
7. Disconnect air lines from front brake chambers, and cover line ends and fittings to prevent the entry of foreign matter.
Caution: Position the air lines and electric wires so they will not be damaged while removing the front axle assembly.
8. Proceed with steps a, b and c, while referring to Section 16: ‘’SUSPENSION’’.
a) Disconnect sway bar links from axle brackets. b) Remove shock absorbers. c) Disconnect five radius rods: one transversal and two longitudinal from subframe, and two upper rods from axle.
9. Remove the bolts and nuts fixing the axle to the left-hand and right-hand side air bellows mounting supports.
10. Using the jacks, slowly lower the axle assembly, and carefully pull away from underneath vehicle.
4.2 REPLACEMENT
Reverse front axle “ Removal” procedure. Ensure cleanliness of air bellows support mounting plates.
Note : Refer to Section 16, ‘’SUSPENSION’’,
Section 14, ‘’Steering’’ and to paragraph 8
‘’Specifications’’ at the end of this section for applicable checks and recommended tightening torques.
5. SERVICE INSTRUCTIONS FOR STEER
AXLE
Refer to GKN Parts and Service Manual for axles annexed at the end of this section.
6. FRONT WHEEL ALIGNMENT
Correct front wheel alignment must be maintained for steering comfort and satisfactory tire life. Road shocks and vibrations, as well as normal stress and strains on the front-end system can, under normal operating conditions, result in loss of front wheel alignment.
Check the front wheel alignment when the following occurs:
1. Every 200,000 miles (320 000 km) or 24 months (normal maintenance);
2. When the vehicle does not steer correctly; or
3. To correct a tire wear condition.
There are two types of front wheel alignment: minor alignment and major alignment .
6.1 MINOR FRONT WHEEL ALIGNMENT
Perform a minor front wheel alignment for all normal maintenance conditions.
Perform the minor front wheel alignment in the following sequence :
1. Inspect all the systems that affect the wheel alignment. See paragraph 6.3, ‘’Inspection
Before Alignment’’ in this section.
2. Check and adjust the hub bearings. See section 13, ‘’Wheels, hubs and Tires’’ under heading 11: Front and Tag Axle Wheel
Hubs.
3. Check and adjust the toe-in.
6.2 MAJOR FRONT WHEEL ALIGNMENT
Perform a major front wheel alignment to correct steering and tire wear conditions.
Perform the major front wheel alignment in the following sequence:
1. Inspect all systems affecting the wheel alignment. See paragraph 6.3, ‘’Inspection
Before Alignment’’ in this section.
2. Check and adjust the hub bearings. See section 13, ‘’Wheels, hubs and Tires’’ under heading 11: Front and Tag Axle Wheel
Hubs.
10 - 4
Note: If steering angle stoppers are changed, a special procedure is required for readjusting gearbox steering limiter. See paragraph 6.5
‘’HYDRAULIC STOP’’ in this section.
3. Check and adjust the turning angle adjustment.
4. Check the camber angle.
5. Check and adjust the caster angle.
6. Check and adjust the toe-in.
6.3 INSPECTION BEFORE ALIGNMENT
Check the following before doing a front wheel alignment:
1. Ensure that the vehicle is at normal riding height. See Section 16, ‘’Suspension’’ under heading 7: ‘’Suspension Height
Adjustment’’ .
2. Ensure that front wheels are not the cause of the problem. See Section 13, ‘’Wheels,
Hubs and Tires’’ . Inspect the tires for wear patterns indicating suspension damage or misalignment. a. Make sure the tires are inflated to the specified pressure. b. Make sure the front tires are the same size and type. c. Make sure the wheels are balanced. d. Check wheel installation and straightness.
3. Check the wheel bearing adjustment.
4. Check steering linkage for bending and pivot points for looseness.
5. Check knuckle pins for evidence of excessive wear.
6. Check radius rods for bending and rubber bushings for evidence of excessive wear.
7. Make sure all fasteners are tightened to the specified torque. Use a torque wrench for verification. As soon as the fastener starts to move, record the torque. Correct if necessary. Replace any worn or damaged fasteners.
Section 10: FRONT AXLE
6.4 TURNING ANGLE ADJUSTMENT
The maximum turning angle is set through the two steering stop screws installed on the axle center. The turning angle is factory adjusted to accommodate the chassis design, and therefore, does not require adjustment on new vehicles. However, it should be checked and adjusted any time any component of the steering system is repaired, disassembled or adjusted.
Check if front tires rub against the frame or if the steering gear has been serviced.
Proceed with the following method to check the steering maximum turning angle :
6.4.1 R.H. Turn Adjustment
Caution : To prevent the steering damper from interfering with the adjustment of turning angles, make sure its fixing bracket is at the correct location on the axle center (refer to section 14
“STEERING”).
1. Turn steering wheel to the right until the boss on the axle center touches the right stop screw.
2. Verify the nearest point of contact of the ball socket body with the air bellows support assembly. Measure the distance between those two points.
3. The distance between these two points should be approximately 1/8 inch (3 mm). If not, the steering stop screws must be readjusted.
4. Verify the nearest point of contact of the drag link with the tire. Measure the distance between those two points.
10 - 5
Section 10: FRONT AXLE
5. The distance should be 1 inch (25 mm) or more. If not, the steering stop screws must be readjusted.
6. This must be done for a full right turn.
7. If readjustment is required: a. Remove the swivel stop screw. b. Add to the stop screw the required number of washers to obtain the proper measure, tighten the stop screw afterwards. Two washers of different thickness are available:
1/16 inch and 3/16 inch.
6.4.2 L.H. Turn Adjustment
1. Turn steering wheel to the left until the boss on the axle center touches the left stop screw.
2. Verify the nearest point of contact of the ball socket body with the air bellows support assembly. Measure the distance between those two points.
3. The distance between these two points should be approximately 1/8 inch (3 mm). If not, the steering stop screws must be readjusted.
4. Check the stroke of the steering stabilizer cylinder (damper). It should not exceed
12.59 inches (320 mm).
5. This must be done for a full left turn.
6. If readjustment is required: a. Remove the swivel stop screw. b. Add to the stop screw the required number of washers to obtain the proper measure, tighten the stop screw afterwards. Two washers of different thickness are available:
1/16 inch and 3/16 inch.
Note : If steering angle stoppers are changed, a special procedure is required for readjusting gearbox steering limiter. See paragraph 6.5
‘’HYDRAULIC STOP’’ in this section.
10 - 6
Section 10: FRONT AXLE
Note : Before steering limiter readjustment, verify vehicle wheel alignment and ensure that oil level is checked and that air bleeding is done.
Refer to ‘ZF-Servocom Repair Manual’’ annexed at the end of Section 14 ‘’Steering’’ under heading ‘Setting and Functional Test.
6.6 FRONT WHEEL CAMBER
Wheel camber is the number of degrees the top of the wheel tilts outward (positive) or inward
(negative) from a vertical angle (Fig. 2).
FIGURE 3: CAMBER
10006
The camber angle is not adjustable. Camber variations may be caused by wear at the wheel bearings, steering knuckle pins or by a bent knuckle or sagging axle center. Steering effort is affected by improper camber, and uneven tire wear will result. Excessive positive camber causes an irregular wear of tire at the outer shoulder and excessive negative camber causes wear at the inner shoulder.
Check
10 - 7
For camber specifications, refer to paragraph
8: ‘’SPECIFICATIONS’’ in this section
1. Use an alignment machine to check the camber angle.
2. If camber reading is not in the specifications, adjust the wheel bearings and repeat the check. If the reading is still not within specifications, verify the steering knuckle pins and axle center.
See instructions in ‘’GKN Parts and Service
Manual For Axles’’ annexed to the end of this section under heading: ‘’Removal of
Stub Axle’’.
3. Check the wheel lateral distortion as instructed in Section 13, ‘’Wheels, Hubs and Tires’’ under heading, ‘’Checking for
Distorted Wheel on Vehicle’’ . If distortion is excessive, straighten or replace wheel(s).
6.7 FRONT AXLE CASTER
For caster specifications, refer to paragraph
8: ‘’SPECIFICATIONS’’ in this section.
Positive caster is the rearward tilt from the vertical axis of the knuckle pin. Negative caster is the forward tilt from the vertical axis of the knuckle pin
(Fig. 3). This vehicle is designed with a positive caster. The purpose of the caster angle is to give a trailing effect. This results in stabilized steering and a tendency for the wheels to return to the straight-ahead position after taking a turn.
Section 10: FRONT AXLE
FIGURE 4: CASTER
10007
Excessive caster results in hard steering around corners. A shimmy may also develop when returning to the straight ahead position (pulling out of curves).
Insufficient caster will cause wandering and steering instability. Caster variations may be caused by a bent axle, tilting or distortion of the side suspension supports, damaged radius rod bushings, or unequal tightening of the front and rear suspension support bolts. Incorrect caster must be corrected by replacing the damaged suspension parts. A precision instrument should be used to measure the caster.
Note : The caster of this vehicle is factory set and is not adjustable. However, if after replacing damaged parts or in case of improper caster due to irregular setting, the front axle caster needs adjustment; it can be adjusted by means of shims
(Prévost #110663) on the left-hand side upper radius rod support in order to obtain minor adjustment.
6.8 FRONT WHEEL TOE-IN
Wheel toe-in is the degree (usually expressed in fractions of an inch) to which the forward part of the vehicle front wheels are closer together than the rear part, measured at wheel centerline height with the wheels in the normal ‘’straight-ahead’’ position of the steering gear.
Incorrect toe-in results in excessive tire wear caused by side slippage and also steering instability with a tendency to wander. Toe-in may be measured from the center of tire tread or from the inside of the tires. Take measurements at both front and rear of axle (see ’’F and ‘’G’’ in fig.
4).
When setting toe-in adjustment, the front suspension must be neutralized; that is, all component parts must be in the same relative position when marking the adjustment as they will be when in operation.
To neutralize the suspension, the vehicle must be rolled forward, approximately ten feet.
FIGURE 5: TOE-IN MEASUREMENTS
10015B
For toe-in specifications, refer to paragraph 8
‘’Specifications’’ in this section.
By rolling the vehicle forward, all tolerances in the front suspension are taken up and the suspension is then in its normal operating position. Neutralizing the front suspension is extremely important, especially if the vehicle has been jacked up in order to mark the tires.
Otherwise, the front wheels will not return to their normal operating position due to the tires gripping the floor surface when the vehicle jack is lowered.
Note: ‘’Toe-in’’ measurements must be taken at the horizontal axis of the wheel centerline.
10 - 8
Section 10: FRONT AXLE
6.8.1 Inspection and Adjustment
Before checking front wheel toe-in, first check the camber angles and make the necessary corrections.
1. Measure the toe-in.
2. If the toe-in measurement is not within the specified tolerance, carry out the following procedure : a. Loosen the pinch bolt nuts and bolts on each tie rod end. b. c.
Turn the tie rod until the specified toe-in measurement is obtained.
Tighten the pinch bolt nuts alternately and progressively to 65-75 lbf • ft (88-102 N • m), thus securing all tie rod joints.
10 - 9
Section 10: FRONT AXLE
7. TROUBLESHOOTING
CONDITION CAUSE CORRECTION
Tires wear out quickly or have uneven tire tread wear.
Vehicle is hard to steer.
Bent or broken steering arm, steering top lever or tie rod assembly.
1. Tires have incorrect air pressure.
2. Tires out-of-balance.
3. Incorrect tag axle alignment.
4. Incorrect toe-in setting.
5. Incorrect steering arm geometry.
1. Low pressure in the power steering system.
2. Steering gear not assembled correctly.
3. Steering linkage needs lubrication.
4. King pins binding.
5. Incorrect steering arm geometry.
6. Caster improperly adjusted.
7. Tie rod ends hard to move.
8. Worn thrust bearing.
1. Put specified air pressure in tires.
2. Balance or replace tires.
3. Align tag axle.
4. Adjust toe-in specified setting.
5. Service steering system as necessary.
1. Repair power steering system.
2. Assemble steering gear correctly.
3. Lubricate steering linkage.
4. Replace king pins.
5. Service steering system as necessary.
6. Adjust caster as necessary.
7. Replace tie rod ends.
8. Replace thrust bearing.
1. Too much pressure in the power steering system.
2. Cut-off pressure of the power steering system improperly adjusted.
3. Vehicle not powered on correctly.
4. Power steering system not installed correctly.
1. Replace damaged part(s), adjust power steering system to specified pressure.
2. Make sure vehicle is powered on correctly.
3. Correctly install the power steering system.
4. Correctly install the power steering system.
Worn or broken steering ball stud.
Worn king pins and knuckle bushings.
Vibration or shimmy of front axle during operation.
1. Drag link fasteners tightened past specified torque.
2. Lack of lubrication or incorrect lubricant.
3. Power steering stops improperly adjusted.
1. Caster not adjusted properly.
2. Wheels and/or tires out-of balance.
3. Worn steering stabilizer cylinder.
1. Replace damaged part(s), tighten drag link fasteners to specified torque.
2. Lubricate linkage with specified lubricant.
3. Adjust stops to specified dimension.
1. Worn or missing seals and gaskets.
2. Incorrect lubricant.
3. Axle not lubricated at scheduled frequency.
4. Incorrect lubrication procedures.
5. Lubrication schedule does not match operating conditions.
1. Replace damaged part(s), replace seals and gaskets.
2. Lubricate axle with specified lubricant.
3. Lubricate axle at scheduled frequency.
4. Use correct lubrication schedule to match operating conditions.
5. Change lubrication schedule to match operating conditions.
1. Adjust caster.
2. Balance or replace wheels and/or tires.
3. Replace steering stabilizer cylinder.
10 - 10
Section 10: FRONT AXLE
8. SPECIFICATIONS
Front Axle
Make ............................................................................................................................. DANA SPICER EUROPE
Model .............................................................................................................................................................. S-84
Front Track ...................................................................................................................... 84.4 inches (2 145 mm)
Rated load capacity............................................................................................................. 16,500 lbs (7 500 kg)
Torque specifications
FIGURE 6: AIR BELLOWS MOUNTING SUPPORT AND AXLE
10009
For more torque specifications, see ‘’GKN Parts and Service Manual for Axles’’ annexed at the end of this section , under heading ‘’Tightening Torque Table for type S-82 Steer Axle.
10 - 11
Section 10: FRONT AXLE
FRONT WHEEL ALIGNMENT SPECIFICATIONS
Front Wheel Alignment
Camber, degrees
R.H. and L.H.
*
Minimal
- ½
Nominal
0
Maximal
+ ½
Caster, degrees
R.H. and L.H.
+ 2 + 2 ¾ + 3 ½
Toe-in (F minus G), inches 1/16 3/32
*
Note : Camber angle changes with loading. The given numbers are for an empty vehicle.
1/8
10 - 12
SECTION 11: REAR AXLES
CONTENTS
1.1 DESCRIPTION ..........................................................................................................................11-2
1.2 DRIVE AXLE LUBRICATION.....................................................................................................11-2
1.3 MAINTENANCE.........................................................................................................................11-2
1.3.1 Checking and Adjusting the Oil Level ................................................................................11-2
1.3.2 Draining and Replacing the Oil ..........................................................................................11-3
1.3.3 Speed Sensors (Anti-Lock Brake system, ABS) ................................................................11-3
1.4 REMOVAL AND REINSTALLATION .........................................................................................11-3
1.5 DISASSEMBLY AND REASSEMBLY........................................................................................11-4
1.6 GEAR SET IDENTIFICATION ...................................................................................................11-4
1.7 ADJUSTMENTS ........................................................................................................................11-4
1.8 FASTENER TORQUE CHART..................................................................................................11-4
1.9 TIRE MATCHING ......................................................................................................................11-4
1.10 DRIVE AXLE ALIGNMENT........................................................................................................11-4
1.10.1 Procedure...........................................................................................................................11-4
1.10.2 Alignment Procedure Using Bee-Line System...................................................................11-6
1.11 AXLE SHAFT SEALING METHOD..........................................................................................11-11
2.1 OIL LUBRICATED WHEEL BEARINGS ..................................................................................11-11
2.2 REMOVAL AND REINSTALLATION .......................................................................................11-12
2.3 TAG AXLE ALIGNMENT .........................................................................................................11-12
3. SPECIFICATIONS..........................................................................................................................11-13
ILLUSTRATIONS
FIGURE 1: TYPICAL SERIAL & MODEL NUMBERS ..............................................................................11-2
FIGURE 2: DIFFERENTIAL AXLE HOUSING BOWL ..............................................................................11-2
FIGURE 3: JACKING POINTS ON FRAME .............................................................................................11-3
FIGURE 4: JACKING POINTS ON DRIVE AXLE.....................................................................................11-4
FIGURE 5: FRONT AND DRIVE AXLE ALIGNMENT ..............................................................................11-6
FIGURE 6: TAG AXLE ALIGNMENT........................................................................................................11-6
FIGURE 7: DRIVE AXLE TOES ...............................................................................................................11-7
FIGURE 8: DRIVE AXLE OFF-TRACKING..............................................................................................11-8
FIGURE 9: EXAMPLE CALCULATION....................................................................................................11-9
FIGURE 10: EXAMPLE CALCULATION................................................................................................11-10
FIGURE 11: AXLE SHAFT INSTALLATION ..........................................................................................11-11
FIGURE 12: OIL FILL CAP.....................................................................................................................11-11
FIGURE 13: JACKING POINTS ON TAG AXLE ....................................................................................11-12
11-1
Section 11: REAR AXLES
AXLE
1.1 DESCRIPTION
The Meritor drive axle is equipped with a single reduction standard carrier mounted in front of the axle housing. The carrier consists of a hypoid drive pinion, a ring gear set and gears in the differential assembly (refer to figure 1 for serial and model numbers).
80W140 for southern climates. In extreme conditions, or for better performance, fill with synthetic gear oil. Check oil level and add (if necessary) every 6,250 miles (10 000 km) or twice a year, whichever comes first (Fig. 2).
FIGURE 1: TYPICAL SERIAL & MODEL NUMBERS
11019
A straight roller bearing (spigot) is mounted on the head of the drive pinion. All other bearings in the carrier are tapered roller bearings. When the carrier operates, there is a normal differential action between the wheels all the time.
FIGURE 2: DIFFERENTIAL AXLE HOUSING BOWL
11007
1.3 MAINTENANCE
Several speed ratios are available for the drive axle. These ratios depend upon the motor and transmission. Also, special applications may suggest slightly different gear ratios.
1.2 DRIVE AXLE LUBRICATION
Additional lubrication information is covered in the Meritor "Maintenance Manual No. 5" annexed to this section. During initial stage of normal operation, tiny metal particles originating from moving parts can be found on mating surfaces. These particles are carried by the lubricant through the assembly and act as lapping compound, which accelerates wear of all parts. To ensure maximum life of the differential and prevent premature failure, the original
"factory fill" lubricant should be drained. Change break-in oil before 3,000 miles (4 800 km) of initial operation (drain the unit while it is still warm from operation), in accordance with the lubrication and servicing schedule.
Proper vehicle operation begins with preventive maintenance, such as good differential use. The most common types of drive axle carrier failures are spinout, shock, fatigue, overheating and lubrication. Avoid neglecting these points since they would be the first steps to improper maintenance, expensive repairs, and excessive downtime.
Inspect the pinion oil seal, axle shaft flange and carrier housing gaskets for evidence of lubricant leakage. Tighten the bolts and nuts, or replace the gaskets and seals to correct leaks.
Maintenance of the axle mountings consists primarily in a regular and systematic inspection of the air suspension units and radius rods, as directed in Section 16, "SUSPENSION".
1.3.1 Checking and Adjusting the Oil Level
Warning: Before servicing, park safely over a repair pit, apply parking brake, stop engine and set battery master switch to the "OFF" position.
Change differential oil and clean the breathers, magnetic fill and drain plugs, every 100,000 miles (160 000 km) or once every two years, whichever comes first.
Use Multigrade gear oil MIL-L-2105-D. Use the
75W90-gear oil for northern climates and the
11-2
1. Make sure the vehicle is parked on a level surface.
Caution: Check the oil level when the axle is at room temperature. When hot, the oil temperature may be 190ºF (88ºC) or more and can cause
burns. Also, a correct reading is not obtained when the axle is warm or hot.
2. Make sure the axle is "cold" or at room temperature.
3. Clean the area around the fill plug. Remove the fill plug from the differential axle housing bowl (Fig. 2).
4. The oil level must be even with the bottom of the hole of the fill plug. a. If oil flows from the hole when the plug is loosened, the oil level is high. Drain the oil to the correct level. b. If the oil level is below the bottom of the hole of the fill plug, add the specified oil.
5. Install and tighten the fill plug to 35-50 lbf•ft
(48-67 N•m).
1.3.2 Draining and Replacing the Oil
Warning: Before servicing, park safely over a repair pit, apply parking brake, stop engine and set battery master switch to the "OFF" position.
1. Make sure the vehicle is parked on a level surface. Put a large container under the axle's drain plug.
Note: Drain the oil when the axle is warm.
2. Remove the drain plug from the bottom of the axle. Drain and discard the oil in an environment friendly manner.
3. Install and tighten the drain plug to 35-50 lbf•ft (48-67 N•m).
4. Clean the area around the fill plug. Remove the fill plug from the differential housing bowl.
5. Add the specified oil until the oil level is even with the bottom of the hole of the fill plug.
Allow the oil to flow through the axle and check the oil level again (lube capacity 41 pints [13,3 liters]).
Caution: The differential overheats when the oil temperature rises above 250ºF (120 ºC).
6. Install and tighten the fill plug to 35-50 lbf•ft
(48-67 N•m).
Section 11: REAR AXLES
1.3.3 Speed Sensors (Anti-Lock Brake system, ABS)
For removing and installing the drive axle speed sensors (for anti-lock brake systems, ABS), refer to Section 12: ‘’Brake and Air System’’ and to
Rockwell WABCO Maintenance Manual: “Anti-
Lock Brake Systems For Trucks, Tractors and
Buses" , annexed at the end of section 12.
1.4 REMOVAL AND REINSTALLATION
The following procedure deals with the removal of the drive axle assembly and its attachments as a unit. The method used to support the axle during removal and disassembly depends upon local conditions and available equipment.
1. Raise vehicle by its jacking points on the body (fig. 3 or see Section 18, "BODY" under heading "VEHICLE JACKING POINTS").
Place jack stands under frame. Remove drive axle wheels (if required, refer to Section 13,
"WHEELS, HUBS AND TIRES".
11-3
FIGURE 3: JACKING POINTS ON FRAME
11020
2. Exhaust compressed air from the air supply system by opening the drain cock on each air reservoir.
3. Disconnect the propeller shaft as directed in
Section 9, "PROPELLER SHAFT", in this manual.
4. On both sides of the vehicle, unscrew fasteners retaining front wheel housing plastic guards, and remove them from vehicle.
5. Disconnect both height control valve links from air spring mounting plate brackets.
6. Remove cable ties securing the ABS cables
(if vehicle is so equipped) to service brake chamber hoses. Disconnect the ABS cable plugs from the drive axle wheel hubs.
Note: When removing drive axle, if unfastening cable ties is necessary for ease of operation, remember to replace them afterwards.
7. Disconnect the brake chamber hoses.
Section 11: REAR AXLES
Note: Position the hoses so they will not be damaged when removing the axle.
8. Install jacks under the axle jacking points to support the axle weight (refer to figure 4).
1.7 ADJUSTMENTS
Adjustments are covered under applicable headings in Meritor's "MAINTENANCE MANUAL
NO. 5", annexed to this section.
1.8 FASTENER TORQUE CHART
A differential fastener torque chart is provided in
Meritor's "MAINTENANCE MANUAL NO. 5", annexed to this section.
FIGURE 4: JACKING POINTS ON DRIVE AXLE
H3B762
9. Remove the four shock absorbers as outlined in Section 16, "SUSPENSION" under heading "SHOCK ABSORBER
REMOVAL".
10. Remove the sway bar.
11. Remove the lower and upper longitudinal radius rod supports from vehicle sub-frame as outlined in Section 16, "SUSPENSION", under heading "RADIUS ROD REMOVAL".
Drive axle tire matching is covered under the applicable heading in Section 13, "WHEELS,
HUBS AND TIRES" in this manual.
1.10 DRIVE AXLE ALIGNMENT
Note: For drive axle alignment specifications, refer to paragraph 3: ‘’SPECIFICATIONS’’ in this section.
12. Remove the transversal radius rod support from the vehicle sub-frame.
13. Remove the two retaining nuts from each of the four air bellows lower mounting supports.
14. Use the jacks to lower axle. Carefully pull away the jacks axle assembly from underneath vehicle.
The drive axle alignment consists in aligning the axle according to the frame. The axle must be perpendicular to the frame. The alignment is achieved with the use of shims inserted between the lower longitudinal radius rod supports and the frame.
Drive axle alignment is factory set and is not subject to any change, except if the vehicle has been damaged by an accident or if there are requirements for replacement.
15. Reverse removal procedure to reinstall drive axle.
Caution: If this setting is significantly altered, the vehicle will produce offset tracking (dog tracking).
Note: suspension components' proper tightening torques.
Note:
Refer to Section 16, “SUSPENSION” for
Refer to section 13 "WHEELS, HUBS
AND TIRES" for correct wheel bearing adjustment procedure.
If the axle has been removed for repairs or servicing and if all the parts are reinstalled exactly in the same place, the axle alignment is not necessary. However, if the suspension supports have been replaced or altered, proceed with the following instructions to verify or adjust the drive axle alignment.
1.5 DISASSEMBLY AND REASSEMBLY
Disassembly and re-assembly procedures are covered under applicable headings in Meritor's
"MAINTENANCE MANUAL, NO. 5", annexed to this section.
Note: When drive axle alignment is modified, tag axle alignment must be re-verified.
1.10.1 Procedure
1. Park vehicle on a level surface, then chock front vehicle wheels.
1.6 GEAR SET IDENTIFICATION
Gear set identification is covered under applicable heading in Meritor's "MAINTENANCE
MANUAL NO. 5", annexed to this section.
11-4
2. Using two jacking points (which are at least
30 inches [76 cm] apart) on drive axle, raise the vehicle sufficiently so that wheels can turn freely at about ½ inch from ground.
Secure in this position with safety stands, and release parking brake.
Section 11: REAR AXLES
Note : See reference numbers on wheel mount sensors (fig. 5).
3. Install wheel mount sensors on front and drive axles (fig. 5). Adjust front axle according to appropriate specifications chart below.
Note: Select axle specifications in the appropriate chart.
FRONT AXLE
INDEPENDENT FRONT SUSPENSION EQUIPPED VEHICLES
Alignment / value Minimum value Nominal value Maximum value
Right camber (deg.) -0.125 0.125 0.375
Left camber (deg.)
Right caster (deg.)
Left caster (deg.)
-0.125
1.5
1.5
0.125
2
2
0.375
2.5
2.5
Total toe (inches) 1/16 3/32 1/8
DRIVE AXLE ALIGNMENT
• With the system installed as for front axle alignment (fig.5), adjust drive axle according to specifications' chart below.
DRIVE AXLE
ALL VEHICLES
Alignment / value Minimum value Nominal value Maximum value
Thrust angle (deg.) -0.11 0 0.11
TAG AXLE ALIGNMENT
• Remove and reinstall all wheel mount sensors on the drive and tag axles (fig. 6);
Note : For an accurate alignment, the tag axle must be aligned with the drive axle.
Note : Reinstall wheel mount sensors as shown in figure 6. For example, the sensor from the right side of the front axle is mounted on the left side of the tag axle. For corresponding wheel mount sensor reference numbers, refer to figure 5.
• Adjust tag axle according to specifications' chart below.
TAG AXLE
ALL VEHICLES
Alignment / value Minimum value Nominal value Maximum value
11-5
Section 11: REAR AXLES
Thrust angle (deg.)
FRONT AXLE
WHEEL
MOUNT
SENSOR
WHEEL
MOUNT
SENSOR
WHEEL
MOUNT
SENSOR
WHEEL
MOUNT
SENSOR
DRIVE AXLE
TAG AXLE
-0.02 0 0.02
FRONT AXLE
WHEEL
MOUNT
SENSOR
DRIVE AXLE
TAG AXLE
WHEEL
MOUNT
SENSOR
WHEEL
MOUNT
SENSOR
WHEEL
MOUNT
SENSOR
FIGURE 6: TAG AXLE ALIGNMENT
FIGURE 5: FRONT AND DRIVE AXLE ALIGNMENT
Note: Refer to Section 16, "SUSPENSION", for proper torque tightening of the longitudinal radius rod support nuts.
Note (2): When the drive alignment is changed, the tag alignment must also be adjusted.
1.10.2 Alignment Procedure Using Bee-Line System
NON-ADJUSTABLE DRIVE AXLE
Proceed as follows to measure the alignment of the drive axle:
1. Measure left and right differential toes (Fig. 7).
2. Calculate the theoretical off-tracking which is required to obtain an ideal drive thrust axis:
Theoretical differential off-tracking = (right differential toe - left differential toe) x distance (in inches)
( 84’’ ) distance = distance between the two targets
3. Measure the real differential off-tracking (Fig. 8).
11-6
Section 11: REAR AXLES
4. Proceed with tag axle alignment detailed below. b d
A toe is positive if the wheel axis is towards the longitudinal axis of the vehicle (inbound) and negative if away from the longitudinal axis (outbound.)
Negative toe Negative toe a c
Left toe = a-b
Right toe = c-d total toe = left toe + right toe
FIGURE 7: DRIVE AXLE TOES
11011
11-7
Section 11: REAR AXLES
Measured differential off-tracking
Target
42" dia.
90
Distance
Vehicle`s longitudinal axis
Differential axle alignment
FIGURE 8: DRIVE AXLE OFF-TRACKING 11012
ADJUSTABLE DRIVE AXLE
1. Measure left and right differential toes (Fig. 7).
2. Calculate the theoretical off-tracking which is required to obtain an ideal drive thrust axis:
Theoretical differential off-tracking = (right differential toe
-
left differential toe) x distance (in inches)
84’’
3. Calculate the acceptable tolerance.
Note: An off-tracking tolerance of one inch over 45 feet is acceptable
Acceptable alignment tolerance for any reference distance is calculated as follows:
Tolerance = Reference distance (in inches)
540
4. Align the off-tracking of the differential within the tolerances (Fig. 9).
5. Measure the ‘’real differential off-tracking’’ obtained (must be within tolerances).
6. Proceed with tag axle alignment detailed below.
11-8
Section 11: REAR AXLES
Example: If we have the following conditions:
Differential left toe: = -1/8"
Differential right toe: = +1/16"
Reference distance = 20 feet.
The theoretical off-tracking required is then: (right toe - left toe) x 20' x 12"/foot
84" or: +1/16" - (-1/8") x 240" = 3/16" x 240" = +0.54"
84" 84"
Since the acceptable tolerance (for a 20 foot reference distance) is 20' x 12"/foot = 0.44"
540
For this example alignment, the differential off-tracking must then be between
(0.54" - 0.44") and (0.54" + 0.44") inches or between 0.1" and 0.98"
Acceptable alignment zone for this example would be from 0.1" to
0.98". The optimal value would be 0.54.
0.98 in.
0.1 in.
0.54 in.
Distance to target = 20'
Left toe = -1/8"
Right toe = +1/16"
FIGURE 9: EXAMPLE CALCULATION
11013
TAG AXLE
1. Measure tag left and right toes.
2. Calculate the off-tracking required by the tag axle to compensate for the tag wheel toes.
Theoretical tag off-tracking = (right tag toe - left tag toe) x distance (inches)
84 inches
3. Calculate the corrected tag off-tracking (in function of differential alignment):
Corrected tag off-tracking = theoretical tag off-tracking + (real differential off-tracking - theoretical differential off-tracking)
11-9
Section 11: REAR AXLES
4. Calculate the acceptable tolerance.
Note: An off-tracking tolerance of 1/16 inch over 20 feet is acceptable.
The tolerance accepted for any reference distance is: reference distance (in inches)
3840
5. Align off-tracking of the tag within tolerances (Fig. 10).
Example: If we have the following conditions:
Tag left toe: = -1/16"
Tag right toe: = +1/8"
Reference distance = 24 feet.
The theoretical off-tracking required would be: (right toe - left toe) x 24' x 12"/ft
84" or: +1/8" - (-1/16") x 288" = 3/16" x 288" = +0.64"
84" 84"
Corrected tag off-tracking = theoretical tag off-tracking + (real differential off-tracking - theoretical differential off-tracking)
Corrected tag off-tracking = +0.64 + (0.74 - 0.54) = +0.84
Since the acceptable tolerance (for a 288" reference distance) is 288" or 0.075"
3840
For this example alignment, the real tag axis would then require to be between
(0.84" - 0.075") and (0.84" + 0.075") inches or between 0.765" and 0.915"
This means you would have to adjust the tag to obtain any point from 0.565" and 0.715" on the target.
Acceptable alignment zone for this example would be from 0.765" to
0.915". The optimal value would be +0.84"
0.765
0.915
0.84
Distance to target = 24 ft.
Left toe = -1/16" Right toe = +1/8"
FIGURE 10: EXAMPLE CALCULATION
11014
11-10
1.11 AXLE SHAFT SEALING METHOD
The following method is to be used to ensure that axle shaft installation is fluid-tight:
Section 11: REAR AXLES c. Install the lock washers and nuts on the studs. Tighten nuts to the correct torque value.
Note: Torque values are for fasteners that have a light application of oil on the threads (refer to
Meritor Maintenance Manual).
9/16-18 plain nut: 110 – 165 lbf•ft(149 – 224 N•m)
5/8-18 plain nut: 150 - 230 lbf•ft (203 - 312 N•m)
FIGURE 11: AXLE SHAFT INSTALLATION
11003
1 ................................................... Silicone sealant*
2 .............................................................. Axle shaft
3 ...................................................................Gasket
4 .............................................................Wheel hub
1. Clean the mounting surfaces of both the axle shaft flange and wheel hub where silicone sealant will be applied. Remove all old silicone sealant, oil, grease, dirt and moisture.
Dry both surfaces.
2. Apply a continuous thin bead of silicone sealant* (Prévost P/N 680053) on the mounting surfaces and around the edge of all fastener holes of both the axle shaft flange and wheel hub.
* GENERAL ELECTRIC Silicone Rubber Adhesive Sealant
RTV 103 Black.
Warning : Carefully read cautions and instructions on the tube of silicone sealant and its packing.
3. Assemble components immediately to permit the silicone sealant to compress evenly between parts. a. Place a new gasket, then install the axle shaft into the wheel hub and differential carrier. The gasket and flange of the axle shaft must fit flat against the wheel hub. b. Install the tapered dowels at each stud and into the flange of the axle shaft. Use a punch or drift and hammer if needed.
The tag axle is located behind the drive axle. It carries a single wheel and tire on each side.
One optional system allows unloading of the tag axle air springs without raising the axle, while the other system enables unloading and raising of the tag axle (refer to the "OPERATOR'S
MANUAL" for location of controls). Both these systems have been designed for the following purposes:
1. Shortening of wheelbase, thus allowing tighter turning in tight maneuvering areas such as parking lots or when making a sharp turn.
2. Transferring extra weight and additional traction to the drive wheels on slippery surfaces.
Caution: Never exceed 30 mph (50 km/h) with tag axle up or unloaded and resume normal driving as soon as possible.
The tag axle service brakes operate only when the axle is in normal driving (loaded) position.
11-11
FIGURE 12: OIL FILL CAP 13017
The oil level on the tag axle and front axle wheel bearings must be maintained between the
“ADD” and “FULL” level mark in the cap or
Section 11: REAR AXLES between 15/16” and 1 3/16” from wheel centerline (23 to 30 mm). These oil level indicators, which are shown as a line, are incorporated to the plastic lens (Fig. 12). To check the oil level after the vehicle has been driven, wait at least 15 minutes to ensure that oil has settled. Differential oil is used to lubricate the drive axle wheel bearings. Maintain the differential oil at the level indicated to ensure adequate lubrication of the wheel bearings.
2.2 REMOVAL AND REINSTALLATION
The following procedure deals with the removal of the tag axle assembly along with the suspension components. The method used to support the axle and suspension components during removal and disassembly depends upon local conditions and available equipment.
1. Raise vehicle by its jacking points on the body (fig. 3 or see Section 18, "BODY" under heading : "VEHICLE JACKING POINTS" ) .
Place jack under frame. Remove drive axle wheels (if required, refer to Section 13,
"WHEELS, HUBS AND TIRES" ).
2. Exhaust compressed air from the air supply system by opening the drain cock on each air reservoir.
3. Install jacks under tag axle jacking points to support the axle weight (refer to figure 13).
8. Remove the two shock absorbers as outlined in Section 16, "SUSPENSION", under
"SHOCK ABSORBER REMOVAL".
9. Disconnect the lower longitudinal radius rods as outlined in Section 16,
"SUSPENSION", under "RADIUS ROD
REMOVAL".
10. Disconnect the transversal radius rod.
11. Disconnect the upper longitudinal radius rod.
12 Remove the air bellows retaining nuts from each of the two upper mounting plates.
13. Use the jacks to move the axle forward to clear the axle off the transmission. Lower the axle.
Caution: On vehicles equipped with an automatic transmission (with or without the output retarder), move tag assembly very carefully. Pay special attention to the U-shaped section, as the transmission end components may be easily damaged through a false maneuver.
14. Reverse removal procedure to reinstall tag axle.
Note: Refer to Section 16 , "SUSPENSION" , for proper torque tightening of suspension components.
Note: Refer to section 13 "WHEELS, HUBS AND
TIRES" for correct wheel bearing adjustment procedure.
2.3 TAG AXLE ALIGNMENT
FIGURE 13: JACKING POINTS ON TAG AXLE OEH3B764
4. Applies only to vehicles equipped with retractable tag axles: Disconnect tag axle lifting chain collars from lower longitudinal radius rods.
Caution : Position the hoses so they will not be damaged when removing axle.
The tag axle alignment consists in aligning the tag axle parallel to the drive axle position. Before aligning the tag axle, proceed with the drive axle alignment (paragraph 1.10). Tag axle alignment is achieved with the use of shims inserted between the lower longitudinal radius rod supports and axle. Tag axle alignment is factory set and is not subject to any change, except if vehicle has been damaged by an accident or if there are requirements for parts replacement.
5. Remove the propeller shaft as directed in
Section 9, "PROPELLER SHAFT", in this manual.
6. Disconnect the tag axle brake chamber hoses.
7. Disconnect hose from the air spring upper mounting plate.
11-12
Caution: If this setting is altered significantly, it will cause excessive tire wear.
Note: It may be necessary to adjust the axle
TOE as well as its alignment. In this case, insert shims (7 min. - P/N 121203 or 15 min. - P/N
121240) in between mounting plate and spindle, as required.
Section 11: REAR AXLES
If axle has been removed for repair or servicing and if all parts are reinstalled exactly in their previous locations, axle alignment is not necessary. However, if the suspension supports
3. SPECIFICATIONS
Drive Axle
Make ............................................................................................................................................................Meritor
Drive track........................................................................................................................ 76.7 inches (1 949 mm)
Gear type .....................................................................................................................................................Hypoid
Axle type .............................................................................................................................................. Full floating
Lube capacity .........................................................................................................................41 pints (19,3 liters) have been replaced or have changed position, proceed with the following instructions to verify or adjust the tag axle alignment.
Drive axle ratio
World Transmission
4.88:1 Standard
4.56:1 Optional
Note: The drive axle alignment consists in aligning the axle with reference to the frame. The axle must be perpendicular to the frame.
Tag Axle
Make ...........................................................................................................................................................Prévost
Rear track ........................................................................................................................ 83.6 inches (2 124 mm)
Axle type ........................................................................................................ Dana Spicer Europe TS5 Hub Unit
Note: The tag axle alignment consists in aligning the tag axle parallel to the drive axle.
11-13
SECTION 12: BRAKE AND AIR SYSTEM
CONTENTS
2. BRAKES...........................................................................................................................................12-5
3.1 M AINTENANCE .............................................................................................................................12-6
(Main) Air Tank ...........................................................................................................12-6
3.1.2 Primary Air Tank.................................................................................................................12-6
3.1.3 Accessory Air Tank ............................................................................................................12-6
3.1.4 Emergency/Parking
3.1.5 Secondary Air Tank............................................................................................................12-6
3.1.6 Kneeling Air Tank ...............................................................................................................12-6
4. AIR SYSTEM EMERGENCY FILL VALVES ...................................................................................12-6
5.1 F ILTER E LEMENT R EPLACEMENT ..................................................................................................12-7
5.2 C LEANING ....................................................................................................................................12-7
6. AIR GAUGES (PRIMARY, SECONDARY AND ACCESSORY).....................................................12-7
8.1 F LEXIBLE H OSES .........................................................................................................................12-8
8.1.1 Copper Tubing....................................................................................................................12-8
8.1.2 Nylon Tubing ......................................................................................................................12-9
8.2 A IR L INE OPERATING T EST ...........................................................................................................12-9
8.3 A IR LINE L EAKAGE T EST ...............................................................................................................12-9
8.4 M AINTENANCE .............................................................................................................................12-9
9.1 M AINTENANCE ...........................................................................................................................12-10
9.2 P RESSURE S ETTING P ROCEDURE ...............................................................................................12-10
10.1 C OMPRESSOR R EMOVAL AND I NSTALLATION ................................................................................12-11
11. GOVERNOR (D-2) ......................................................................................................................12-11
12. EMERGENCY/PARKING BRAKE CONTROL VALVE (PP-1)..................................................12-11
13. EMERGENCY / PARKING BRAKE OVERRULE CONTROL VALVE (RD-3) ..........................12-12
15. DUAL BRAKE APPLICATION VALVE (E-10P) ........................................................................12-12
15.1 B RAKE P EDAL A DJUSTMENT .......................................................................................................12-12
12 -1
Section 12: BRAKE AND AIR SYSTEM
15.1.1 Maintenance.....................................................................................................................12-12
16. STOPLIGHT SWITCHES............................................................................................................12-13
17. PARKING BRAKE ALARM SWITCH ........................................................................................12-13
18. BRAKE RELAY VALVE (R-12 & R-12DC) ................................................................................12-13
20. SPRING BRAKE VALVE (SR-1)................................................................................................12-13
22. LOW PRESSURE INDICATOR (LP-3).......................................................................................12-14
23. SHUTTLE-TYPE DOUBLE CHECK VALVE (DC-4)..................................................................12-14
25. AIR SYSTEM TROUBLESHOOTING ........................................................................................12-15
27.1 DISC BRAKES .............................................................................................................................12-15
27.1.1 Disc
Maintenance ........................................................................................................12-16
27.1.3 Roadside Inspection for Knorr/Bendix Air Disc Brakes....................................................12-17
Removal....................................................................................................................12-18
27.1.5 Checking Pad Wear .........................................................................................................12-18
27.1.6 Important Pad and Rotor Measurements .........................................................................12-18
27.1.7 Checking Caliper Guidance and Seal Condition..............................................................12-18
Installation.................................................................................................................12-19
27.1.10 Adjusting Running Clearance .................................................................................12-19
27.1.11 Brake Tools...................................................................................................................12-20
Brake Pads ...................................................................................................12-20 specifications....................................................................................................12-20
29. AIR BRAKE TROUBLESHOOTING ..........................................................................................12-21
30.1 M AINTENANCE ...........................................................................................................................12-24
30.2 E MERGENCY /P ARKING B RAKE M ANUAL R ELEASE ........................................................................12-25
30.3 BRAKE CHAMBER R EMOVAL ........................................................................................................12-25
30.4 BRAKE CHAMBER I NSTALLATION ..................................................................................................12-25
30.5 BRAKE CHAMBER D ISASSEMBLY ..................................................................................................12-25
12-2
Section 12: BRAKE AND AIR SYSTEM
31.1 T ROUBLESHOOTING AND T ESTING ...............................................................................................12-26
31.1.1 Blink Code Troubleshooting and Repair ..........................................................................12-27
31.2 ABS C OMPONENTS ....................................................................................................................12-29
Control Unit (ECU) ..........................................................................................12-29
31.2.2 Maintenance.....................................................................................................................12-29
31.3 ABS M ODULATOR V ALVE ...........................................................................................................12-29
31.3.1 Maintenance.....................................................................................................................12-29
31.4 S ENSORS ..................................................................................................................................12-29
31.4.1 Maintenance.....................................................................................................................12-30
Installation............................................................................................................12-30
31.5 S PRING CLIP ..............................................................................................................................12-30
31.5.1 Maintenance.....................................................................................................................12-30
33. SPECIFICATIONS ......................................................................................................................12-32
ILLUSTRATIONS
FIGURE 1: AIR RESERVOIRS LOCATION .............................................................................................12-5
FIGURE 2: REAR VALVE LOCATION (TYPICAL)...................................................................................12-6
FIGURE 3: FRONT SERVICE COMPARTMENT.....................................................................................12-6
FIGURE 4: ACCESSORY AIR FILTER ....................................................................................................12-7
FIGURE 5: BENDIX AD-9 AIR FILTER/DRYER.......................................................................................12-8
FIGURE 6: WABCO 1200 AIR FILTER/DRYER.......................................................................................12-8
FIGURE 7: AIR PRESSURE REGULATING VALVE .............................................................................12-10
FIGURE 8: AIR PRESSURE REGULATOR ..........................................................................................12-10
FIGURE 9: AIR COMPRESSOR AND GOVERNOR..............................................................................12-11
FIGURE 10: D-2 GOVERNOR ...............................................................................................................12-11
FIGURE 11: PP-1 ...................................................................................................................................12-11
FIGURE 12: RD3 ....................................................................................................................................12-12
FIGURE 13: TW1 ...................................................................................................................................12-12
FIGURE 14: BRAKE PEDAL ADJUSTMENT.........................................................................................12-12
FIGURE 15: DELCO SWITCH ...............................................................................................................12-13
FIGURE 16: BENDIX SWITCH ..............................................................................................................12-13
FIGURE 17: R-12 ...................................................................................................................................12-13
FIGURE 18: QR-1 ..................................................................................................................................12-13
FIGURE 19: SR-1...................................................................................................................................12-14
FIGURE 20: PR-4...................................................................................................................................12-14
FIGURE 21: LP-3 ...................................................................................................................................12-14
FIGURE 22: DC-4...................................................................................................................................12-14
FIGURE 23: BRAKE PAD CHECK .........................................................................................................12-16
FIGURE 24: CLEARANCE INSPECTION..............................................................................................12-16
FIGURE 25:RUNNING CLEARANCE....................................................................................................12-16
FIGURE 26: ADJUSTER PINION...........................................................................................................12-17
FIGURE 27: BOX WRENCH ON ADJUSTER PINION...........................................................................12-17
FIGURE 28: CALIPER AXIAL MOVEMENT...........................................................................................12-17
FIGURE 29: BRAKE PAD CHECK .........................................................................................................12-18
FIGURE 30: PAD REMOVAL .................................................................................................................12-18
FIGURE 31: PAD WEAR........................................................................................................................12-18
FIGURE 32: ROTOR AND PAD WEAR LIMITS .....................................................................................12-18
FIGURE 33: CALIPER GUIDANCE........................................................................................................12-19
FIGURE 34: RUBBER BOOTS ..............................................................................................................12-19
12-3
Section 12: BRAKE AND AIR SYSTEM
FIGURE 35: PAD INSTALLATION .........................................................................................................12-19
FIGURE 36: RUNNING CLEARANCE ...................................................................................................12-20
FIGURE 37: BRAKE PAD CHECK ........................................................................................................12-20
FIGURE 38: TORQUE SPECIFICATION...............................................................................................12-20
FIGURE 39: TORQUE SPECIFICATION...............................................................................................12-20
FIGURE 40: AIR-OPERATED BRAKING SYSTEM XLII........................................................................12-22
FIGURE 41: FRONT AXLE BRAKE AIR CHAMBER..............................................................................12-24
FIGURE 42: TAG AXLE BRAKE AIR CHAMBER...................................................................................12-24
FIGURE 43: ABS 4S/4M CONFIGURATION .........................................................................................12-27
FIGURE 44: ABS BLINKER SWITCH & ECU LOCATION .....................................................................12-29
FIGURE 45: ABS MODULATOR VALVE ...............................................................................................12-29
FIGURE 46: ABS SENSOR LOCATION ................................................................................................12-30
FIGURE 47: SPRING CLIP ....................................................................................................................12-30
FIGURE 48: HOSE FITTINGS ...............................................................................................................12-30
FIGURE 49: HOSE FITTING..................................................................................................................12-31
FIGURE 50: HOSE FITTING..................................................................................................................12-31
FIGURE 51: HOSE FITTING..................................................................................................................12-31
12-4
The basic air system consists of an air compressor, reservoirs, valves, filters and interconnecting lines and hoses. It provides a means for braking, operating controls and accessories, and suspension (refer to Section
16, "Suspension" , for complete information on suspension description and maintenance). An air system schematic diagram is annexed in the technical publications box provided with the vehicle for better understanding of the system.
2. BRAKES
This vehicle uses both the service brake and emergency/parking brake. The service brake air system is divided into two independent circuits to isolate front brakes from rear brakes, thus providing safe breaking in the event that one circuit fails. Front axle brakes operate from the secondary air system, while brakes on both the drive axle and tag axle operate from the primary air system.
Note : The tag axle service brake operates only when the axle is in normal ride position (loaded and down).
Section 12: BRAKE AND AIR SYSTEM
Furthermore, the brake application or release, which is speed up by a pneumatic relay valve
(R-12), will start with the rear axles and will be followed by the front axle, thus providing uniform braking on a slippery road. The vehicle is also equipped with an Anti-Lock Braking System
(ABS), which is detailed later in this section.
The drive and tag axles are provided with spring-loaded emergency/parking brakes, which are applied automatically whenever the control valve supply pressure drops below 40 psi (275 kPa). The optional emergency/parking brake overrule system allows the driver to release spring brakes, and to move the vehicle to a safe parking place, such as in the case of a selfapplication of these brakes due to a drop in air pressure.
The air coming from the air dryer is first forwarded to the wet air tank, then to the primary
(for the primary brake system), secondary (for the secondary brake system), and accessory
(for the pneumatic accessories) air tanks
(Fig. 1).
Two additional air reservoirs may be installed on the vehicle: the kneeling air tank and emergency/ parking brake overrule air tank.
FIGURE 1: AIR RESERVOIRS LOCATION
12-5
24006
Section 12: BRAKE AND AIR SYSTEM
3.1 MAINTENANCE
Ensure that the wet (main) air tank is purged during pre-starting inspection. In addition, it is good practice to purge this reservoir at the end of every working day. The remaining reservoirs must be purged at every 12,500 miles (or 20 000 km) or once every year, whichever comes first.
3.1.1 Wet (Main) Air Tank
This reservoir, located above the L.H. wheel of drive axle in the rear wheelhousing, is provided with a bottom drain valve. A recommended purge using the bottom drain valve should be done every 12,500 miles (20 000 km), or once a year, whichever comes first.
3.1.2 Primary Air Tank
This reservoir is located above the R.H. wheel of the drive axle and is provided with a bottom drain valve (Fig. 1). It is recommended to purge the primary air tank every 12,500 miles
(20 000 km) or once a year, whichever comes first.
FIGURE 2: REAR VALVE LOCATION (TYPICAL)
12162
3.1.3 Accessory Air Tank
The accessory air tank is installed close to the front axle and is provided with a bottom drain valve (Fig. 1).
Purge the reservoir by it’s drain valve every
12,500 miles (20 000 km) or once a year, whichever comes first.
12-6
FIGURE 3: FRONT SERVICE COMPARTMENT 12144
3.1.4 Emergency/Parking Brake Overrule Air
Tank
Installed on vehicles equipped with this option, this reservoir is located in the front wheelhousing (Fig. 1). It is provided with a bottom drain valve.
Purge this reservoir every 12,500 miles (20 000 km) or once a year, whichever comes first.
3.1.5 Secondary Air Tank
This tank is located in the front wheelhousing, behind the steering axle (Fig. 1). It is provided with a bottom drain valve
Purge this reservoir every 12,500 miles (20 000 km) or once a year, whichever comes first.
3.1.6 Kneeling Air Tank
The kneeling air tank is installed on vehicles equipped with the Kneeling or Hi/Low-Buoy options. It is located in the front wheelhousing
(Fig. 1), and is provided with a bottom drain valve.
4. AIR SYSTEM EMERGENCY FILL VALVES
All vehicles come equipped with two emergency fill valves that enable system pressurization by an external source such as an air compressor.
The rear valve is located in the engine compartment and is accessible from engine
R.H. side door (Fig 2.). It can be positioned close to the door hinge or the door opening.
Caution : Maximum allowable air pressure is
125 psi (860 kPa). Air filled through these two points will pass through the standard air filtering system provided by Prevost. Do not fill system by any point on the system.
The front valve is located in the front service compartment close to R.H. side of door frame
(Fig. 3).
These two air system emergency fill valves are fitted with the same valve stems as standard tires, and can be filled by any standard external air supply line.
The rear air system emergency fill valve will supply air for all systems (brakes, suspension and accessories) while the front fill valve will supply air for accessories only.
5. ACCESSORY AIR FILTER
FIGURE 4: ACCESSORY AIR FILTER 12088
This filter is located inside the front service compartment (Fig. 3). Its main function consists in filtering the air supplied to the accessory air system, when connected to an external supply line. Ensure filter is purged whenever supplying the system with an external air line and at least every 12,500 miles (20 000 km).
To purge, open drain valve (Fig. 4), let the moisture come out, then close the drain valve.
12-7
Section 12: BRAKE AND AIR SYSTEM
5.1 FILTER ELEMENT REPLACEMENT
Replace filter element whichever of the following occurs first: every 100,000 miles (160 000 km), every two years, or whenever differential pressure exceeds 15 psi (105 kPa) between filter inlet and outlet ports. Check condition of all three O’rings for damage. Replace when necessary (Fig. 4).
5.2 CLEANING
Clean filter body and bowl with a warm water and soap solution. Rinse thoroughly with clean water. Blow dry with compressed air making sure the air stream is moisture free and clean.
Pay particular attention to the internal passages.
Inspect all parts for damage and replace if necessary.
6. AIR GAUGES (PRIMARY, SECONDARY
AND ACCESSORY)
The air pressure gauges, located on the dashboard (see "Operator's Manual" or
“Owner’s Manual” ), are connected to the DC-4 double check valve, located on the pneumatic accessory panel in the front service compartment.
The latter is connected to the air lines running from the primary and secondary air tanks, as shown on the pneumatic system diagram provided in the technical publications box. The accessory air gauge is connected to the accessory air tank using the drain valve connector. The vehicle should never be set in motion until the buzzer alarm and warning lights turn off, i.e. when air pressure registers at least
66 psi (455 kPa). Moreover, if pressure drops below 66 psi (455 kPa), the "Low air pressure" warning lights will turn on, and the "Low air pressure" buzzer will sound. Stop the vehicle immediately, determine and correct the cause(s) of pressure loss. Check the gauges regularly with an accurate test gauge. Replace the gauge with a new unit if there is a difference of 4 psi
(27 kPa) or more in the reading.
Section 12: BRAKE AND AIR SYSTEM
FIGURE 5: BENDIX AD-9 AIR FILTER/DRYER 12155
The air filter/dryer is located in front of rear wheelhousing above drive axle (Fig. 5 & 6). Its purpose is to remove moisture that could damage the air system before the air enters the system reservoir. The air filter/dryer also filters the air to remove dirt, compressor oil, and other contaminants that can damage the system.
Change cartridge every 100,000 miles (160 000 km) or once every two years, whichever comes first. The air dryer may be purged for maintenance purposes using the remote drain valve located in the engine compartment and accessible through the engine compartment
R.H. side door. The valve is positioned over the battery assembly, close to the door hinge or close to the L.H. side of door opening depending on type of vehicle (Fig. 2).
Copper tubing, nylon-reinforced tubing, and flexible hoses are used to connect the units in the pneumatic system, including air brake system, suspension system and accessory systems such as the entrance door, fresh air damper cylinder, air horns, etc. Furthermore, the nylon tubing is color coded to ease identification.
Refer to the following table for the complete color identification code. Service instructions for each type of air line are also provided under the applicable headings.
Color Circuit
Red Secondary
Green Primary and Delivery
Blue Suspension
Black Accessory
A flexible hose is used normally where it is impractical to use copper or nylon tubing due to constant flexing during operation, such as brake chamber hoses. Hose connections should be tested for leakage at least every 6,250 miles (10
000 km) or twice a year, whichever comes first and tightened or replaced if necessary. Any hose which is chafed, worn or kinked should be replaced.
Teflon-braided stainless steel hoses used in the engine compartment must be replaced only with similar hoses.
FIGURE 6: WABCO 1200 AIR FILTER/DRYER
12152
Maintenance and repair information on the relevant air dryer are supplied in the applicable booklet annexed to this section under reference
“Service Data Sheet SD-08-2412” for AD-9 or
“Maintenance Manual No 34” for Wabco.
12-8
Annealed copper tubing with three-piece compression type fittings are used in the engine compartment where heat and high pressure resistant lines are required. Connections should be checked for leakage at least every 6,250 miles (10 000 km) or twice a year, whichever comes first. Tighten or replace when necessary.
When replacing copper tubing, the parts must be free of burrs, copper cuttings, and dirt. Blow out tubing with compressed air. Any such particles will destroy sealing seats in air control units. Also, new tubing must be the same size as the old one.
Always use new tubing ring when replacing tubing. When tightening tube connector nuts, tighten to the specified torque to ensure an airtight connection (refer to "Various Fittings
Tightening Torques" at the end of this section).
Overtightening will cause leakage. Apply SAE
10 oil or spray white grease (Prévost part No.
680343) to ball sleeves, tubes and male threads. Torque to the minimum value and check for leaks. If leaking occurs, back off tube nut about ½ turn and retorque to a higher than minimum value.
Nylon tubing is used for air lines in areas where usage of this material is suitable. Nylon tubing is flexible, durable, and weather resistant. When replacing an air line, use nylon tubing only where it has been used previously.
Nylon air lines must never be routed in areas where temperature could exceed 200 o
F (93 o
C).
Caution : Nylon air lines should be used to replace existing nylon lines only, and must comply with the color identification code to ease pneumatic system troubleshooting.
8.2 AIR LINE OPERATING TEST
If any trouble symptom such as slow brake application or slow brake release indicates a restricted or clogged air line, disconnect the suspected tube or hose at both ends and blow through it to clear the passage.
Inspect tubing and hose for partial restriction that may be caused by dents or kinks. If such a condition is found, the tubing or hose should be replaced.
8.3 AIR LINE LEAKAGE TEST
With air system fully charged and the brakes applied, coat all tubing and hose connections with a soapy solution to check for air leakage.
No leakage is permitted. Leakage can sometimes be corrected by tightening the connection. If this fails to correct the leakage, new fittings, nylon tubing, copper tubing, teflon-braided stainless steel and flexible hoses must be installed as applicable.
Section 12: BRAKE AND AIR SYSTEM
8.4 MAINTENANCE
Inspect all lines for cuts, swelling, kinks or other damage or deterioration. Check for lines being pinched by other components. Retaining clips and ties must be in place.
Any support or bracket should be in good condition and mounted firmly in position. Hose spring guards should be in usable condition and not distorted. Particular attention should be given to long lines. Any supporting component
(clips, ties, grommets, etc.) must be secured to prevent against unnecessary vibration and eventual loosening of connection. Any detected leak should be repaired. Be sure nylon lines are not near areas of intense heat. Check for any missing grommets or loose material where chafing or cutting may occur. Replace with new material as required. In general, lines should be securely located in position and free from any binding condition which would hinder air flow.
9. PRESSURE REGULATING VALVES
There is one pressure regulator for the belt tensioners, and an optional one installed on vehicles equipped with the world transmission output retarder.
The belt tensioner pressure regulating valve is located in the engine compartment above the doors and is used to limit the air pressure in belt tensioners to 50 ± 2 psi (345 ± 15 kPa) for series
60 engines (Fig. 7).
The optional regulator is either located in the engine compartment (accessible through the engine R.H. side door) or in the R.H. side rear service compartment. It is used for transmission retarder and should be adjusted to 80 ± 3 psi
(550 ± 20 kPa).
Belt
Tensioner
Retarder
Air Pressure
(psi) series 60
50 ± 2
80 ± 3
Air Pressure
(kPa) series 60
345 ± 15
550 ± 20
12-9
Section 12: BRAKE AND AIR SYSTEM
9.1 MAINTENANCE
Every 100,000 miles (160 000 km) or once every two years, whichever comes first, disassemble the regulating valve and wash all metal parts in
7). Examine the diaphragm; if cracked, worn or damaged, replace with a new one. If the valve is excessively grooved or pitted, it should be replaced. Replace any other part that appears worn or damaged. After reassembly, adjust to the specified pressure setting and check for air leakage.
FIGURE 7: AIR PRESSURE REGULATING VALVE
12141B
9.2 PRESSURE SETTING PROCEDURE
Remove the dust cap from the pressure check valve (Fig. 8). Attach a pressure gauge at this port and check the pressure reading. If the pressure reading is incorrect, adjust as follows:
1. Loosen the locking nut, turn the adjustment screw counterclockwise to decrease pressure by approximately 10 psi (70 kPa) below the required pressure.
2. Turn the adjustment screw clockwise to increase the pressure slowly until the required pressure setting is reached. Tighten the locking nut.
3. Remove pressure gauge and replace dust cap on the air pressure check valve.
12-10
FIGURE 8: AIR PRESSURE REGULATOR
12151
10. AIR COMPRESSOR (TU-FLO 750)
The air compressor is located on starter side of the engine, on the rear of the engine gear case
(Fig. 9). Its function is to provide and maintain air under pressure to operate devices in brake and air systems.
This air compressor also drives the engine fuel pump which is bolted to the rear end of the compressor. The compressor crankshaft is designed to accept a drive coupling which is placed between the compressor and fuel pump.
The compressor is driven by the bull gear, and is water cooled. Engine coolant is fed to the compressor through a flexible hose tapped into the block water jacket and connected to the rear of the compressor. Coolant returns from the right of the compressor (governor side) through a flexible hose to the engine cylinder head.
The air is taken from the air intake manifold and entered in the back of the compressor. The compressed air is pushed into the discharge line located on top of the compressor, which sends air to the air dryer. Lubricating oil is supplied to the compressor by a line from the cylinder block oil gallery connected to the air compressor.
Lubricating oil returns to the engine crankcase through the air compressor drive assembly.
Maintenance and repair information on the
TU-FLO 750 air compressor is supplied in the applicable booklet annexed to this section under reference number SD-01-344.
Section 12: BRAKE AND AIR SYSTEM
FIGURE 10: D-2 GOVERNOR
12. EMERGENCY/PARKING BRAKE
CONTROL VALVE (PP-1)
A push-pull control valve mounted on the L.H. lateral console is provided for parking brake application or release. The spring brakes are self-actuated whenever the control valve supply pressure drops below 40 psi (275 kPa). In the
UP position, brakes are ON. In the DOWN position, brakes are RELEASED. A protective case around the knob prevents accidentally releasing the brakes.
12137
FIGURE 9: AIR COMPRESSOR AND GOVERNOR
12160
10.1 COMPRESSOR REMOVAL AND
INSTALLATION
1. Exhaust compressed air from air system by opening the drain valve of each air tank.
2. Drain the engine cooling system. See
Section 5: " Cooling System ".
3. Identify and disconnect all air, coolant and oil lines from the compressor and governor assembly.
4. Access the compressor by the engine R.H. side compartment. Remove the four compressor mounting bolts and the two fuel pump support bracket bolts.
5. Slide air compressor rearward to disengage the hub from coupling. Remove the air compressor.
Reverse removal procedure for installation.
11. GOVERNOR (D-2)
The governor is mounted on the air compressor
(Fig. 9), its function is to maintain the system pressure between a minimum and a maximum value. Maintenance and repair information on
D-2 governor is supplied in the applicable booklet annexed to this section under reference number SD-01-503.
12-11
FIGURE 11: PP-1
12142
Maintenance and repair information on this valve is supplied in the applicable booklet annexed to this section under reference number
SD-03-3611.
Section 12: BRAKE AND AIR SYSTEM
Remove the valve the following way:
1. Drain the air system.
2. Access this valve by tearing out the finishing panel, which holds the controls in place
(Fig. 11).
3. Disconnect the air tubes.
4. Remove the retaining screws.
5. Service or replace the valve.
6. Installation is the reverse of removal.
13. EMERGENCY / PARKING BRAKE
OVERRULE CONTROL VALVE (RD-3)
A RD-3 control valve is used with the optional parking brake overrule system. In the case of self-application of spring brakes due to a pressure drop, the brakes can be released by holding down this control valve. Maintenance and repair information on this valve is supplied in the applicable booklet annexed to this section under reference number SD-03-3611.
FIGURE 13: TW1
12138
15. DUAL BRAKE APPLICATION VALVE
(E-10P)
The E-10P dual brake valve is a floor mounted, foot-operated type brake valve with two separate supply and delivery circuits. This valve is located in the front service compartment (Fig. 14).
15.1 BRAKE PEDAL ADJUSTMENT
After brake pedal replacement or repair, adjust the pedal to its proper position according to the following procedure:
1. Replace the linkage, loosen threaded rod lock nuts and screw or unscrew the threaded adjustment rod in order to obtain a
45 o brake pedal inclination (Fig. 14).
2. Tighten threaded rod lock nuts.
15.1.1 Maintenance
Maintenance and repair information on the E-10P dual brake application valve is supplied in the applicable booklet annexed to this section under reference number SD-03-830.
FIGURE 12: RD3 12136
14. FLIP-FLOP CONTROL VALVE (TW-1)
A flip-flop control valve mounted on the L.H. lateral console is provided to unload tag axle air springs (and to lift tag axle if vehicle is so equipped). Another one controls the low-buoy system (coaches only). It is a manually operated
"on-off" valve. Maintenance and repair information on this valve is supplied in the applicable booklet annexed to this section under reference number SD-03-3602.
12-12
FIGURE 14: BRAKE PEDAL ADJUSTMENT
12040
16. STOPLIGHT SWITCHES
Two electro-pneumatic stoplight switches are mounted on the dual brake application valve (E-
12). The upper one is used for the primary air circuit while the lower one is used for the secondary air circuit. Both switches are connected in parallel and have the same purpose, i.e. completing the electrical circuit and lighting the stoplights when a brake application is made. The upper switch (AC Delco) is designed to close its contact between 2 psi and
4 psi (14 kPa to 28 kPa) (Fig. 15), while the lower one (Bendix, SL-5) closes its contact at 4 psi (28 kPa) (Fig. 16). The switches are not a serviceable items; if found defective, the complete unit must be replaced.
Section 12: BRAKE AND AIR SYSTEM valve, and which function is to speed up the application and release of the service brakes.
One R-12DC valve supplies the drive axle service brake air line, while the other two valves supply independently both the tag axle right and left service brake air line and act as interlock valves. These valves are accessible from under the vehicle at the level of the tag axle.
Maintenance and repair information on these valves is supplied in the applicable booklets annexed to this section under reference number
SD-03-1064 and SD-03-1068.
FIGURE 15 : DELCO SWITCH
12139
FIGURE 17: R-12
12074
19. QUICK RELEASE VALVES (QR-1)
The quick release valve is located on the front axle service brakes air line and permit rapid exhaust of air pressure from brakes, thus decreasing the brake release time.
Maintenance and repair information on this valve is supplied in the applicable booklet annexed to this section under reference number SD-03-901.
FIGURE 16: BENDIX SWITCH
12140
17. PARKING BRAKE ALARM SWITCH
Refer to the appropriate annexed booklet
(Bendix, SL-5 Stop Light Switch; reference no.
SD-06-2501).
The parking brake alarm uses the same switch as the stoplights. It is mounted on the spring brake valve and operates in conjunction with a
NC relay to sound a warning alarm by completing the electrical circuit when the ignition key is turned OFF with parking brake released.
FIGURE 18: QR-1
20. SPRING BRAKE VALVE (SR-1)
12075
18. BRAKE RELAY VALVE (R-12 & R-12DC)
The primary air system includes three brake relay valves being supplied by the dual brake
12-13
The spring brake valve is located on the pneumatic accessory panel in the front service compartment. The function of the SR-1 is to modulate the spring brakes during the application of the foot brake valve in the event of
Section 12: BRAKE AND AIR SYSTEM loss of service brake pressure. Maintenance and repair information on the spring brake valve is supplied in the applicable booklet annexed to this section under reference number SD-03-
4508.
22. LOW PRESSURE INDICATOR (LP-3)
Maintenance and repair information on the low pressure indicators is supplied in the applicable booklet annexed to this section under reference number SD-06-2.
The air system includes two low pressure switches (Fig. 21), both located on the pneumatic accessory panel in the front service compartment. One serves for the parking brake signal, the remaining pressure switch monitors the parking brake telltale panel indicator. Their pressure setting is 66 ± 6 psi (455 ± 40 kPa
FIGURE 19: SR-1
12076
21. PRESSURE PROTECTION VALVE (PR-4)
Maintenance and repair information on the pressure protection valve is supplied in the applicable booklet annexed to this section under reference number SD-03-2010.
The air system includes two pressure protection valves (Fig. 20). One valve is installed on the manifold block, and insures at all times a minimum pressure of 70 psi (482 kPa) in the suspension air system in the event that a pressure drop occurs in either the suspension air system or accessory air system. This valve is located in the front service compartment besides the air filter.
FIGURE 21: LP-3
12135
23. SHUTTLE-TYPE DOUBLE CHECK VALVE
(DC-4)
Maintenance and repair information on the shuttle-type double check valve is supplied in the applicable booklet annexed to this section under reference number SD-03-2202.
The double check valve is located on the pneumatic accessory panel in the front service compartment. In the event of a pressure drop in either the primary or secondary system, this unit will protect the emergency /parking brake control valve and the intact portion of the air system from pressure loss.
FIGURE 20: PR-4 12174
The other valve is installed on the accessory air tank, and insures a minimum pressure of 70 psi
(482 kPa) in the accessory air system in the event that a pressure drop occurs in either the suspension air system or braking air system
(refer to Fig. 1 for accessory air tank location).
12-14
FIGURE 22: DC-4
12134
Section 12: BRAKE AND AIR SYSTEM
• Leaks in air system valves. 24. AIR HORN VALVE
The air horn valve is located in the L.H. front service compartment. The air horn button is on the center of the steering wheel. Refer to section 23 “ACCESSORIES” for more information.
25. AIR SYSTEM TROUBLESHOOTING
The following list has been designed to help in troubleshooting some of the most common problems in the air system and main causes.
For air brakes troubleshooting, refer to “ Air
Brakes Troubleshooting” in this section. For more troubleshooting information, refer to the manufacturer's brochures annexed to this section.
Air pressure doesn't rise to, or doesn't maintain, a normal setting:
• Defective air gauge (registering incorrectly).
• Excessive leaking in air system.
• Reservoir drain cock open.
• Governor poorly adjusted or defective.
• Defective
• Worn compressor or excessive wear on piston and/or ring.
• Air pressure rises to normal setting too slowly.
Excessive leaking in air system:
• Clogged engine air cleaner.
• Worn compressor or excessive wear on piston and/or ring.
• Engine speed too low.
Air pressure rises above a normal setting:
• Defective air gauge (registering incorrectly).
• Governor poorly adjusted or defective.
• Restriction in line between governor and compressor unloading mechanism.
Air pressure drops quickly when engine is stopped:
• Leaks in compressor discharge valve.
• Leaks in governor.
• Leaks in air lines.
26. BRAKE OPERATION
The vehicle braking system uses both service and parking air-operated brakes. The air system is divided into two independent circuits to isolate the front axle brakes and the rear axle brakes
(drive and tag), thus providing safe brake operation in the event that one circuit of the system fails. The primary circuit is connected to the drive and tag axle brakes, while the secondary circuit is connected to the front axle brakes. The tag axle service brakes operate only when the axle is in the normal driving
(loaded) position. The spring-type emergency brakes are mounted on the drive and tag axles, and will apply automatically if primary system pressure falls below 40 psi (276 kPa). The optional parking brake override system can cancel the parking brakes, enabling the driver to move the vehicle to a safe parking place. To operate this system, push down and hold the control knob located on the R.H. side of the driver’s seat (see "Operator's Manual" for more details).
Furthermore, brake application or release, which is speed up by a pneumatic relay valve (R-12), will start with the rear axles and be followed by the front axle, thus providing uniform braking on a slippery surface. The vehicle may also be equipped with an Anti-lock Brake System (ABS), detailed later in this section.
Brake and air system maintenance consists of periodic inspections. Check all parts for damage and brake adjustment (refer to subsequent headings in this section for more details).
Ensure all fasteners are tight (refer to “ Specifications" for recommended tightening torques).
27. AIR BRAKES
12-15
Knorr-Bremse SB7000 disc brakes are used on all axles. The front and drive axle discs are actuated by 24 square inch effective area air brake chambers, while on tag axle, the brake chambers have a 16 square inch effective area for service brake and a 16 square inch effective area for emergency/parking brakes. The Knorr-
Bremse SB7000 brakes are supplied with automatic clearance (slack) adjusters as standard equipment for easier adjustment. For more information on disc brake components and
Section 12: BRAKE AND AIR SYSTEM maintenance, refer to the manufacturer's brochure at the end of this section.
27.1.1 Disc Brake Pads
Brake pads have to be checked on a regular basis depending on the vehicle operation. The remaining thickness of the pads should never be less than 3/32 in (2 mm). To check pad condition without removing the wheel, verify the position of guide bushing (6) relatively to guide sleeve (4) (see Fig. 23). When guide sleeve is in alignment with guide bushing, brake pad thickness has to be checked more precisely with the wheel removed. When replacing brake pads, all four pads on an axle have to be changed at the same time. There is no inner or outer pad, since all pads are the same. Once removed, worn pads should be replaced in their original position. booster, ensure that all pneumatic components in the braking system are functioning properly.
Note: A residual pressure of 2-3 PSI in the system is sufficient to prevent the brakes from releasing. Also the stop light switch can operate with as little as 1 PSI, therefore an illuminated brake light does not mean brakes are dragging.
2. Pad to rotor clearance inspection:
Remove clip and washer (26 & 45, Fig. 24), push down retainer bar (11), pull out pin (44) and remove retainer bar. Push caliper toward actuator (center of vehicle) for maximum clearance.
FIGURE 23: BRAKE PAD CHECK
12117
27.1.2 Caliper Maintenance
Use the following procedure for brake calipers servicing. The procedure must be followed in proper sequence to ensure that only needed repairs or replacements are performed on calipers. Problems such as hot brakes or cracked rotors may be effects of sticking calipers, too-small clearance between rotor and pad or possible trapped air pressure in the brake chamber. If any of these symptoms occur, perform this procedure before replacing the rotor to ensure the cause of the problem is properly solved.
1. Check for presence of residual pressure:
To check if there is any residual air pressure in the brake chamber, make four or five brake applications, then try to turn the wheel manually, if the wheel does not turn, use a wrench to crack the air line and listen for trapped air in the brake chamber then try to turn the wheel manually again. If you find trapped air in the brake
FIGURE 24: CLEARANCE INSPECTION
3. Measure pad to rotor clearance:
Place a long feeler gauge (long enough to of 0.008 inch (0.2 mm).
12-16
FIGURE 25:RUNNING CLEARANCE
12119 measure across entire tappet surface) between the tappet and the backing plate of the pad, measure clearance at both tappets. Clearance should range between 0.020 and 0.035 inch (0.5 mm and 0.9 mm), with a maximum difference between tappet measurements on same brake
12116
Section 12: BRAKE AND AIR SYSTEM
4. Checking the adjuster
Warning: Use only a standard box wrench on the adjuster hexagonal pinion. Do not overtorque the pinion as overtorquing will damage the pinion. a) Remove cap (37, Fig. 26). b) Using a box wrench (8 mm), turn the adjuster pinion (23, Fig. 26) counterclockwise about 2 - 3 clicks to increase running clearance. By operating the braking system about 5 - 10 times (30 PSI or 2 bar), the wrench should turn clockwise in small increments if the adjuster is functioning correctly (Figs. 26 and 27).
Note:
With increasing number of applications, the incremental adjustment will decrease. c) In case of malfunction, i. e. the pinion or box wrench: i) Does not turn. ii) Turns only with the first application. iii) Turns forwards then backwards with every application.
In any of the above cases, the automatic adjuster has failed and the caliper must be replaced. In such cases the brakes can be adjusted manually to run a short distance. d) Take the box wrench off. Replace the cap and check for proper sealing.
FIGURE 27: BOX WRENCH ON ADJUSTER PINION
12118
27.1.3 Roadside Inspection for Knorr/Bendix
Air Disc Brakes
The coach is equipped with air disc brakes and therefore, cannot be inspected using the requirements for chamber stroke or visible lining clearance or lining thickness as specified for drum brakes. The roadside inspector should use the following instructions to determine that the air disc brakes are within proper adjustment and have sufficient pad wear thickness.
The Knorr/Bendix air disc brake is designed to move freely, with minimal force, in the axial direction on the two sliding pins as identified in figure 28. The movement in the axial direction should not exceed 2 mm (5/64”).
FIGURE 26: ADJUSTER PINION
12120
FIGURE 28: CALIPER AXIAL MOVEMENT
12132
The pad thickness can be seen but would require removal of the tire and rim. An indicator of the pad wear condition is available by inspecting the floating pin location in relation to the rubber bushing as shown in figure 29. When pads are in new thickness condition, the pin will be exposed (C) 19 mm (¾”). When the pads are worn to replacement conditions, the pin will be nearly flush to the bushing (D) or within 1 mm
(3/64”) of the edge of the rubber bushing.
12-17
Section 12: BRAKE AND AIR SYSTEM
27.1.6 Important Pad and Rotor Measurements
FIGURE 29: BRAKE PAD CHECK
12117
27.1.4 Pad Removal
Turn adjuster pinion (23) counterclockwise to increase pad to rotor clearance (a clicking noise will be heard). Push caliper toward actuator and remove pads (12).
Caution: Do not apply brakes while pads are removed as this could cause over stroke damage to the adjusting mechanism.
FIGURE 32: ROTOR AND PAD WEAR LIMITS 12113
A = Rotor thickness (new): 45 mm;
B = Rotor thickness (worn): 37 mm Requires replacement;
C = Overall thickness of pad (new): 30 mm;
D = Backplate: 9 mm;
E = Minimum thickness of pad material: 2 mm;
F = Minimum allowed thickness of overall backplate and friction material: 11 mm.
Replacement necessary .
FIGURE 30: PAD REMOVAL
27.1.5 Checking Pad Wear
Minimum friction material thickness is 2 mm (A,
Fig. 31)
New friction material has a thickness of 21 mm
(B, Fig. 31)
FIGURE 31: PAD WEAR
12111
27.1.7 Checking Caliper Guidance and Seal
Condition
Perform sliding test. You must be able to slide the caliper easily at any time. Sliding test should be performed at least every three months or more often depending on the type of operation.
Sliding Test (Refer to Fig. 33): a) Using hand pressure only, the caliper (1) must slide freely with its guide pin arrangements (4-7) across a distance of 1 3/16 inch
(30 mm) when the pads are removed. The sleeve (5) is sealed using the boot (9) and the cap (10).
12112
12-18 b) The rubber components (9 and 10) should show no damage. The positioning must be checked. If necessary the caliper has to be repaired using the guide kit (part #611168) or with the seal and guide kit (part
#611199). When repairing a caliper with the above kits, make sure all parts in the kit are used. Use special green grease (Prévost
#683344) to reassemble the slide pin into the bushing, white or yellow grease (Prévost
Section 12: BRAKE AND AIR SYSTEM
#683345) may be used for all other lubrication needs. c) Depending on caliper manufacturing date, black paint may be present on the unsealed pin (short pin). Paint on the slide pin can prevent the caliper from sliding properly especially when the pad starts to wear. If paint is present on the pin, separate the pin from the bushing, clean and reinstall the pin according to procedure.
Note: Do not attempt to use thinner or alcohol to clean the pin without removing it as it may damage the rubber bushing.
FIGURE 34: RUBBER BOOTS
12115
27.1.9 Pad Installation
Turn adjuster pinion (23, Fig. 35) counterclockwise until tappets are fully retracted and clean pad seat area. Slide caliper to full outboard position and install outside pad. Slide caliper to full inboard position and install inside pad.
Warning: It is recommended to change all pads on an axle at the same time.
FIGURE 33: CALIPER GUIDANCE 12114 FIGURE 35: PAD INSTALLATION
12111
27.1.8 Checking the Tappet Boots a) The rubber boots (13, Fig. 34) should show no damage, check the attachment.
Caution: Any ingress of water and dirt will lead to corrosion and may affect the function of the actuation mechanism and adjuster unit. b) If boots are damaged but show no corrosion, the boots and tappets should be replaced (Prévost #611177).
12-19
27.1.10 Adjusting the Running Clearance a) Insert a feeler gauge 0.028 inch (0.7 mm thickness) between tappet and pad backplate (Fig. 36). Turn adjuster pinion clockwise until 0.028 inch (0.7 mm) clearance is achieved. Replace cap (37) (Prévost #
641313). b) To ensure a constant running clearance between the rotor and pads, the brake is equipped with an automatic adjuster unit.
When the pads and rotor wear, the running clearance between the pads and rotor
Section 12: BRAKE AND AIR SYSTEM increases. The adjuster (23, Fig. 36) and turning device turn the threaded tubes by the amount necessary to compensate the wear.
Total running clearance should be between
0.020 and 0.035 inch (0.5 and 0.9 mm). Smaller clearances may lead to overheating problems.
12117 FIGURE 37: BRAKE PAD CHECK
For proper caliper maintenance, refer to the following figures.
FIGURE 36: RUNNING CLEARANCE 12116
Four brake tools are available from Prévost to facilitate disc brake maintenance: a) #641321, Tappet with boot (item 13). b) #641322, Caliper inner boot (item 9). c) #641323, Caliper bushing (item 7). d) #641435, Fork for boot tappet (item 13).
Maintenance tip
Using the following procedure, pad wear can be determined without removing the wheel.
27.1.12 Checking Brake Pads
Brake pads have to be checked on a regular basis depending on the vehicle operation. The remaining thickness of the pads should never be less than 3/32 inch (2 mm). To check pad condition without removing the wheel, verify the position of guide bushing (6) relatively to guide sleeve (4) (Fig. 37). When guide sleeve is in alignment with guide bushing, brake pad thickness must be checked more precisely with wheel removed. When replacing the brake pads, all four pads on an axle have to be changed at the same time. There is no inner or outer pad, since all pads are the same. Worn pads should be replaced in the same position.
FIGURE 38: TORQUE SPECIFICATION 12145
FIGURE 39: TORQUE SPECIFICATION 12149
12-20
28. SAFE SERVICE PROCEDURES
Most recently manufactured brake linings no longer contain asbestos fibers. Instead of asbestos, these linings contain a variety of ingredients, including glass fibers, mineral wool, aramid fibers, ceramic fibers, and carbon fibers.
At present, OSHA (Occupational Safety and
Health Administration) does not specifically regulate these non-asbestos fibers, except as nuisance dust. Medical experts do not agree about the potential long-term risks from working with and inhaling non-asbestos fibers.
Nonetheless some experts think that long-term exposure to some non-asbestos fibers could cause diseases of the lung, including pneumoconiosis, fibrosis, and cancer. Therefore, lining suppliers recommend that workers use caution to avoid creating and breathing dust when working on brakes that contain non-asbestos fibers.
Warning :
Section 12: BRAKE AND AIR SYSTEM
When cleaning the work area, NEVER use compressed air or dry sweeping to clean the work area. Use an industrial vacuum with a
HEPA filter and rags soaked in water and wrung until nearly dry. Dispose of used rags with care to avoid getting dust into the air. Use an approved respirator when emptying vacuum cleaners and handling used rags.
Wash your hands before eating, drinking or smoking. Do not wear your work clothes home.
Vacuum your work clothes after use and then launder them separately, without shaking, to prevent fiber dust from getting into the air.
Material safety data sheets on this product, as required by OSHA, are available from Rockwell and Knorr-Bremse.
Whenever possible, work on brakes in a separate area away from other operations.
Always wear a respirator approved by NIOSH
(National Institute of Occupational Safety and
Health) or MSHA (Mine Safety and Health
Administration) during all brake service procedures. Wear the respirator from removal of the wheels through assembly.
NEVER use compressed air or dry brushing to clean brake parts or assemblies. OSHA recommends that you use cylinders that enclose the brake. These cylinders have vacuums with high efficiency (HEPA (Health and Environment
Protection Agency)) filters and workmans’ arm sleeves. But, if such equipment is not available, carefully clean parts and assemblies in the open air.
Clean brake parts and assemblies in the open air. During disassembly, carefully place all parts on the floor to avoid getting dust into the air. Use an industrial vacuum cleaner with a HEPA filter system to clean dust from the brake drums, backing plates and other brake parts. After using the vacuum, remove any remaining dust with a rag soaked in water and wrung until nearly dry.
If you must grind or machine brake linings, take additional precautions because contact with fiber dust is higher during these operations. In addition to wearing an approved respirator, do such work in an area with exhaust ventilation.
12-21
29. AIR BRAKE TROUBLESHOOTING
The following tests and check lists have been designed to identify the cause(s) of a sluggish performance and/or leaks in the system. These tests require very little time to perform, and give you a general idea of the system condition. Each test is provided with a corresponding check list which will guide you to the most common causes of problems.
Before performing any test, check all air lines for kinks or dents, and hoses for signs of wear, drying out or overheating.
Warning : When working on or around brake system and its related components, the following precautions should be observed:
Always block vehicle wheels. Stop engine when working under a vehicle. Keep hands away from chamber push rods and slack adjusters as they may apply when system pressure drops.
Never connect or disconnect a hose or line containing air pressure. It may whip as air escapes. Never remove a component or pipe plug unless you are sure all system pressure has been depleted.
Section 12: BRAKE AND AIR SYSTEM
FIGURE 40: AIR-OPERATED BRAKING SYSTEM XLII
12-22
Section 12: BRAKE AND AIR SYSTEM
Never exceed recommended air pressure and always wear safety glasses when working with air pressure. Never look into air jets or direct them at anyone.
OR
9 Repair or replace governor as necessary after checking that compressor unloader mechanism operates correctly.
Never attempt to disassemble a component until you have read and understood the recommended procedures. Some components contain powerful springs and injury can result if not properly disassembled. Use only proper tools and observe all precautions pertaining to the use of those tools.
More than 30 seconds to build-up pressure from 85 to 100 psi (585 - 690 kPa) at full engine RPM
9 Perform a telltale light and gauge test.
Replace entire cluster if found defective
9 Check compressor strainer or inlet line. If restricted, clean or replace element or faulty line.
Always clean connecting piping and/or fittings, and coat pipe threads with Teflon pipe sealant before installing any air brake system component.
9 Check compressor head or discharge line for carbon deposits or restriction. Clean or replace as necessary.
PRESSURE BUILD-UP / LOW PRESSURE
WARNING / CUTOFF POINT / GOVERNOR
CUTOUT
9 If discharge valves leak, pull head and correct or replace cylinder head.
9 If drive is slipping, replace gear.
CONDITION: Vehicle parked, wheels blocked.
1. Completely drain air reservoirs.
2. Start engine and run at fast idle. Low pressure warning lights should be "On" .
3. Start checking pressure at 50 psi (344 kPa).
4. Low pressure warning lights and buzzer should go off at or above 60 psi (415 kPa).
5. At 85 psi (586 kPa), run engine at full rpm, then check that build up time to 100 psi (690 kPa) is 30 seconds or less.
9 If inlet valves are stuck, open or leaking severely, replace unloader kit, inlet valves and/or seats as necessary.
9 If drain cock is found open, close it.
9 If governor leaks when "unloaded" , clean or
9 replace inlet valve or replace governor.
Listen for air leaks and repair.
9 Redo list to check all items repaired or replaced.
6. Governor cutout. Cuts out at the correct pressure of 120-125 psi (826-861 kPa).
7. Governor cut-in. Reduce service air pressure to governor cut-in. The difference between cut-in and cut-out pressures should not exceed 25 psi (172 kPa). Cut-in pressure should be 100 psi (689 kPa) or more, raise pressure if needed.
For common corrections, refer to the following check list:
AIR SUPPLY RESERVOIR LEAKAGE
CONDITION : Full pressure, engine stopped, parking brake applied
1. Allow at least 1 minute for pressure to stabilize.
2. Stop engine, then check air pressure gauge for 2 minutes. Note any pressure drop.
3. Pressure should not drop by more than 3 psi
(20 kPa) per minute.
High or Low Warning Cutoff Point
For common corrections, refer to the following check list:
9 Perform a telltale light and gauge test.
Replace entire cluster if found defective.
High or Low Governor Cutout Point
9 Perform a telltale light and gauge test.
Replace entire cluster if found defective.
9 Adjust governor to desired cut-in.
Excessive air loss:
12-23
9 With the primary air system at normal operating pressure (95 - 125 psi (655 - 860 kPa)), coat all air line connections and pneumatic components with a water and soap solution. Bubbles will indicate an air leak, and none should be permissible.
Repair or replace defective parts.
Section 12: BRAKE AND AIR SYSTEM
9 Listen for leaks and correct as required.
9 Redo test to check all items repaired or replaced.
BRAKE SYSTEM AIR LEAKAGE
CONDITION : Full pressure, engine stopped, parking brake released.
1. Apply service (foot) brakes, allow at least 1 minute for pressure to stabilize.
2. Hold down foot valve for 2 minutes while observing air pressure gauge on the dashboard.
3. Pressure drop should not be more than 3 psi
(20 kPa) per minute.
For common corrections, refer to the following check list.
Excessive leakage on brake service side:
9 With the primary air system at normal operating pressure (95 - 125 psi (655 -
860 kPa)) and foot brake applied, coat all air line connections and brake pneumatic components with a water and soap solution.
Bubbles will indicate an air leak, and none should be permissible. Repair or replace defective parts.
9 Listen for leaks and correct as required.
9 Redo test to check all items repaired or replaced.
FIGURE 41: FRONT AXLE BRAKE AIR CHAMBER
12158
30. BRAKE AIR CHAMBER
If this vehicle is equipped with Knorr-Bremse
SB7000 disc brakes on all axles, it also uses
“Knorr-Bremse” brake chambers. The tag and drive axle chambers consist of two separate air chambers, each having its own diaphragm and push rod. They are used as a service brake chamber, an emergency brake in case of air pressure loss and a spring-applied parking brake. Refer to figures 41 and 42.
FIGURE 42: TAG AXLE BRAKE AIR CHAMBER
12126
30.1 MAINTENANCE
The front axle brake air chambers are used only for service brake duty (Fig. 41).
Every 6,250 Miles (10 000 km) or twice a year, whichever comes first depending on type of operation:
Check all hoses and lines. They should be secure and in good condition.
Every 100,000 Miles (160 000 km) or once a year, whichever comes first depending on type of operation:
12-24
1. Disassemble and clean all parts.
2. Install new diaphragm or any other part if worn or deteriorated.
Note : When the diaphragm, spring, or both are replaced, they should be replaced in the corresponding chamber on the same axle.
3. Perform an airtighteness test: a) Make and hold a full brake application. b) Coat clamping ring(s) with a soapy solution.
If leakage is detected, tighten clamping ring only enough to stop leakage. Do not overtighten as this can distort sealing surface or clamping ring. Coat area around push rod hole (loosen boot if necessary). No leakage is permitted. If leakage is detected, the diaphragm must be replaced.
30.2 EMERGENCY/PARKING
MANUAL RELEASE
Warning : Never stand in the axis line of the spring brake chambers, especially when caging the spring.
Drive Axle
1. Block the wheels to prevent the vehicle from moving.
Section 12: BRAKE AND AIR SYSTEM
3. To manually reset the emergency/parking brake, turn the bolt clockwise.
30.3 BRAKE CHAMBER REMOVAL
Warning: To prevent personal injuries, brakes should be inoperative prior to working on any of their components.
Warning : To prevent personal injuries, brake chambers should be made inoperative by releasing spring tension prior to disposal.
1. Block the wheels to prevent the vehicle from moving.
2. Safely support vehicle at the recommended body jacking points.
3. To gain access to a given brake air chamber, the corresponding wheel can be removed (refer to Section 13: "Wheels,
Hubs and Tires" ).
4. Exhaust compressed air from system by opening the drain valve of each reservoir.
5. For the drive and tag axles brake chambers, manually release spring brakes (refer to
" Emergency/Parking Brake, Manual
Release" procedure in this section).
6. Disconnect air line(s) from brake chamber.
7. Remove the cotter pin connecting brake chamber and slack adjuster (drive axle).
2. Remove the release stud tool from its storage place on drive axle brake air chamber.
3. Remove the access plug from the end of the spring chamber, then insert the release stud through the opening. Turn the release stud
¼ turn (clockwise) to anchor it into the spring plate. Install the flat washer and nut, then turn the nut clockwise to cage the spring. Repeat on the opposite side.
8. Unbolt and remove the brake chamber from vehicle.
30.4 BRAKE CHAMBER INSTALLATION
Reverse removal procedure, then check brake adjustment.
Warning: Make sure the release stud is properly anchored in spring plate receptacle prior to caging the spring.
Caution : Always clean air lines and fittings, and coat pipe threads with teflon pipe sealant before reconnecting air lines.
4. To manually reset the emergency/parking brake, turn the nut counterclockwise. Reinstall access plugs on the spring chambers, and release stud tools in their storage places.
Tag Axle
30.5 BRAKE CHAMBER DISASSEMBLY
Warning: Spring brake chambers, on drive and tag axles contain an extremely high compressive force spring, which can possibly cause serious injury if special precautions are not taken when working around this area.
1. Block the wheels to prevent the vehicle from moving.
To avoid such injury, the following recommendations must be applied:
2. Turn the release bolt counterclockwise to cage the power spring (approx. 2.5 inches
(6 cm)). Repeat on the opposite side.
12-25
1. Prévost recommends the installation of a new spring brake chamber if it is found to be defective.
Section 12: BRAKE AND AIR SYSTEM
2. Spring brake chamber maintenance and/or repair must be performed by trained and qualified personnel only.
3. Before manually releasing spring brakes, visually check spring brake for cracks and/or corrosion.
4. On “MGM” brake chambers (drive axle), make sure the release stud is properly anchored in spring plate receptacle prior to caging the spring.
1. Block the wheels to prevent the vehicle from moving.
2. Safely support vehicle at the recommended body jacking points.
Note : To gain access to a given brake air chamber, the corresponding wheel can be removed (refer to Section 13: "Wheels, Hubs and Tires"). maintaining adequate steering control on slippery roads.
The ABS continuously monitors wheel behavior during braking. Sensors on each wheel of front and drive axles (tag axle is slave to drive axle) transmit data to a four channel electronic processor which senses when any wheel is about to lock. Modulator valves quickly adjust the brake pressure (up to 5 times per second) to prevent wheel locking. Each wheel is therefore controlled according to the grip available between its tire and the road.
5. Never stand in the axis line of the spring brake chambers, especially when caging the spring.
Warning: To prevent personal injury, brakes should be inoperative before working on any components.
With this device, the vehicle is brought to a halt in the shortest possible time, while remaining stable and under the driver's control.
Since the braking system has dual circuits, the
ABS is also provided with a secondary system should a fault develop in the ABS. Anti-lock systems are a parallel system which does not hinder brake functioning in case of failure.
Braking system functions in normal, non anti-lock controlled operation during ABS system failure.
The ABS system consists of two diagonally related circuits, only the half of the system which has sustained damage or other fault is switched off (i.e. wheels return to normal non-ABS braking). The other diagonal half remains under full ABS control.
3. Exhaust compressed air from air system by opening the drain valve of each reservoir.
4. For the drive and tag axles brake chambers, manually release spring brakes (refer to
“ Emergency/Parking Brake Manual Release" procedure in this section).
Note : ABS is active on service brake, transmission retarder, Jake brake, but is inactive on emergency/parking brake.
5. Remove clamp ring, remove and discard the existing diaphragm. Install the new diaphragm squarely on body.
Note : The ABS system is inoperative at speeds under 4 mph (6 Km/h). Illumination of ABS telltale indicator at these speeds is normal.
6. Reverse the procedure for assembly. Tap clamp ring to ensure proper seating. Check for proper operation before placing vehicle in service.
31. ANTI-LOCK BRAKING SYSTEM (ABS)
This device has been designed to ensure stability and permit steering control of vehicle during hard braking, and to minimize its stopping distance whatever the road conditions are. On slippery roads and generally in emergency situations, over-braking frequently induces wheel lock. The anti-lock braking system provides maximum braking performance while
Caution : Disconnect the ECU or pull the ABS fuse before towing vehicle.
31.1
ABS WARNING LAMP
TROUBLESHOOTING AND TESTING
For troubleshooting and testing of the vehicle's anti-lock braking system, refer to Rockwell
WABCO Maintenance Manual: “Anti-Lock Brake
Systems For Trucks, Tractors and Buses" , at the end of this section. Blink codes are listed in this section hereafter.
Caution : Turn Blink switch OFF before driving.
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Ignition ON
Normal Operation
After Servicing ABS System ABS lamp does not go out
Existing Fault
Section 12: BRAKE AND AIR SYSTEM
ABS lamp comes on at ignition momentarily for a bulb check, then goes out.
System is OK. at ignition.
ABS lamp does not go out at ignition.
When vehicle is driven at speeds above 4 mph
(6 km/h), lamp goes out.
System is OK.
Lamp does not go out at speeds above 4 mph (6 km/h) – a fault exists in the ABS system.
FIGURE 43: ABS 4S/4M CONFIGURATION
31.1.1 Blink Code Troubleshooting and Repair
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Section 12: BRAKE AND AIR SYSTEM
BLINK CODE
1 st
Digit 2 nd
Digit
Action required
Check ABS Modulator valve, valve cable, and
2 1-6* modulator valve).
Adjust wheel sensor to touch wheel. Check
AC output @ 30 RPM.
*1-6 Key
1 Right front steer axle
(curb side)
2 Left front steer axle
(driver’s side)
3 Right rear drive axle
(curb side)
4 Left rear drive axle
(driver’s side)
6 1-6* Check for damaged tooth wheel.
7
7
3
4
Check brake relay connections.
Check ABS warning light connections.
Check vehicle voltage (9.5-14 volts). Verify accuracy of blink code and clear from ECU memory.
Verify accuracy of blink code and clear from ECU
8 4 If code does not clear, it may be necessary to reconfigure or replace the ECU.
8 5 Check ABS ground connections.
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The main components of the ABS system are listed hereafter. Refer to each component for its specific function in the system and for proper maintenance.
31.2.1 Electronic Control Unit (ECU)
This control unit is located in the front service compartment, (refer to figure 44 for location).
According to the data transmitted by the sensors
(number of pulses/sec is proportional to the speed of each wheel), the electronic control unit determines which wheel is accelerating or decelerating. It then establishes a reference speed (average speed) from each wheel data, and compares the speed of each wheel with this reference speed to determine which wheel is accelerating or decelerating.
As soon as wheel deceleration or wheel slip threshold values are exceeded, the electronic control unit signals a solenoid control valve to limit the excessive brake pressure produced by the driver in the appropriate brake chamber.
Section 12: BRAKE AND AIR SYSTEM
31.3 ABS MODULATOR VALVE
This ABS system is equipped with four modulator valves, located between the brake chamber and the relay valve or quick release valve (Fig. 45). Note that there is only one solenoid valve controlling the drive and tag axle wheels on the same side (tag axle is slave to drive axle).
FIGURE 44: ABS BLINKER SWITCH & ECU LOCATION
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31.2.2 Maintenance
No specific maintenance is required. The ECU is not serviceable. When found to be defective, replace.
Caution : In order to protect the ABS electronic control unit from voltage surges, always disconnect before performing any welding procedure on vehicle.
FIGURE 45: ABS MODULATOR VALVE
12084
This is an "On/Off" type valve, i.e., at brake application, the valve exhausts air from the brake chamber when the electronic unit senses that the corresponding wheel speed is decreasing in relation to the other wheels.
31.3.1 Maintenance
No specific maintenance is required for the solenoid control valve.
31.4 SENSORS
The sensors are mounted on the front and drive axle wheel hubs (Fig. 46). The inductive sensors consist essentially of a permanent magnet with a round pole pin and a coil. The rotation of the toothed wheel alters the magnetic flux picked up by the coil, producing an alternating voltage, the frequency of which is proportional to wheel speed. When wheel speed decreases, magnetic flux decreases proportionately. Consequently, the electronic control unit will command the solenoid control valve to decrease the pressure at the corresponding brake chamber.
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Section 12: BRAKE AND AIR SYSTEM wheel. Ensure mounting is rigid, as it is an important criterion for adequate sensor operation.
Note : This installation should be of the "press fit" type.
The spring clip retains the sensor in its mounting bracket close to the toothed pulse wheel. The gap between the sensor end and teeth is set automatically by pushing the sensor in the clip hard up against the tooth wheel, and the latter knocks back the sensor to its adjusted position
(Fig. 47).
FIGURE 46: ABS SENSOR LOCATION 12153
31.4.1 Maintenance
No specific maintenance is required for sensors, except if the sensors have to be removed for axle servicing. In such a case, sensors should be lubricated with a special grease (Prévost
#680460) before reinstallation. Refer to paragraph “Sensor Installation” for details.
Note: The resistance value, when sensors are checked as a unit, must be equal to 1,75 k ohms. To check the sensors for proper output voltage after the sensors and toothed wheels have been assembled to the axle, connect a suitable AC voltmeter across the output terminals. With the hubs rotating at 30 rpm, the output voltages should read from 50 to 1999 mV to be acceptable.
FIGURE 47: SPRING CLIP
31.5.1 Maintenance
The spring clip requires no specific maintenance.
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32. FITTING TIGHTENING TORQUES
45 ο Flare and Inverted Flare: Tighten assembly with a wrench until a solid feeling is encountered. From that point, tighten 1/6 turn (Fig. 48).
31.4.2 Sensor Installation
The following procedure deals with sensor installation on the axle wheel hubs. Read procedure carefully before reinstalling a sensor, as its installation must comply with operational tolerances and specifications.
1. Apply recommended lubricant (Prévost
#680460) to spring clip and sensor.
Caution : Use only this type of grease on the sensors.
2. Insert spring clip in the holder on hub. Make sure the spring clip tabs are on the inboard side of the vehicle. Push in until the clip stops.
3. Push the sensor completely inside the spring clip until it is in contact with the tooth
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FIGURE 48: HOSE FITTINGS 12053
Compression: Tighten nut by hand (Fig. 49).
From that point, tighten using a wrench the number of turns indicated in the chart hereafter.
Fitting size
Pipe diameter
(inches)
2 1/8
3 3/16
4 1/4
5 5/16
6 3/8
8 1/2
10 5/8
12 3/4
16 1
Number of additional turns required following hand tightening
Section 12: BRAKE AND AIR SYSTEM the number of turns indicated in the following chart.
Piping diameter
(inches)
1/4, 3/8, 1/2
5/8, 3/4
Number of additional turns required following hand tightening
2
3
FIGURE 49: HOSE FITTING
12054
NTA-Type Plastic Tubing: Hand tighten nut
(Fig. 50). From that point, tighten using a wrench the number of turns indicated in the following chart.
Tubing diameter
(inches)
Number of additional turns required following hand tightening
1/4 3
3/8 to 1/2 4
5/8 to 3/4 3 ½
FIGURE 51: HOSE FITTING 12056
Pipe Tightening: All connections must be hand tightened. From that point, tighten a minimum of
2 ½ additional turns.
Note: Use Locktite (Prévost number 680098) pipe sealant to seal pipe thread.
FIGURE 50: HOSE FITTING
12055
AB-Type Copper Piping: Hand tighten nut
(Fig. 51). From that point, tighten with a wrench
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Section 12: BRAKE AND AIR SYSTEM
33. SPECIFICATIONS
Air Compressor
Make............................................................................................................................. Bendix Westinghouse
Model..............................................................................................................................................Tu-Flo 750
Capacity (at 1250 rpm) ............................................................................................16.5 cfm (0,467 m 3 /min.)
Supplier number.................................................................................................................................. 109426
Prévost number................................................................................................................................... 641362
Governor
Make............................................................................................................................. Bendix Westinghouse
Model......................................................................................................................................................... D-2
Cut-in pressure....................................................................................................... 95-105 psi (655-724 kPa)
Cutout pressure.................................................................................................... 120-125 psi (827-861 kPa)
Supplier number.................................................................................................................................. 284358
Prévost number................................................................................................................................... 640964
Air Dryer
Make............................................................................................................................. Bendix Westinghouse
Model.......................................................................................................................................................AD-9
Heater consumption.........................................................................................................................100 watts
Supplier number.................................................................................................................................. 108229
Prévost number................................................................................................................................... 641243
Desiccant cartridge kit supplier number.............................................................................................. 107796
Desiccant cartridge kit Prévost number .............................................................................................. 641244
Make..................................................................................................................................... Rockwell Wabco
Model................................................................................................................................System Saver 1200
Heater consumption.........................................................................................................................100 watts
Supplier number..........................................................................................................................RWABK-095
Prévost number................................................................................................................................... 641337
Desiccant cartridge kit supplier number........................................................................................... R950011
Desiccant cartridge kit Prévost number .............................................................................................. 641278
Flip-Flop Control Valve
Make............................................................................................................................. Bendix Westinghouse
Model...................................................................................................................................................... TW-1
Type ..................................................................................................................................................... On-Off
Supplier number.................................................................................................................................. 229635
Prévost number................................................................................................................................... 640136
Emergency/Parking Brake Control Valve
Make............................................................................................................................. Bendix Westinghouse
Model....................................................................................................................................................... PP-1
Automatic release pressure .................................................................................... 40 psi (275 kPa) nominal
Supplier number.................................................................................................................................. 287325
Prévost number................................................................................................................................... 641128
Emergency/Parking Brake Overrule Control Valve
Make............................................................................................................................. Bendix Westinghouse
Model.......................................................................................................................................................RD-3
Supplier number.................................................................................................................................. 281481
Prévost number................................................................................................................................... 640472
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Section 12: BRAKE AND AIR SYSTEM
Dual Brake Application Valve
Make............................................................................................................................. Bendix Westinghouse
Model..................................................................................................................................................... E-10P
Supplier number................................................................................................................................ 5006280
Prévost number................................................................................................................................... 641856
Stoplight Switches
Make............................................................................................................................. Bendix Westinghouse
Model....................................................................................................................................................... SL-5
Contact close (ascending pressure) ........................................................................ 4 psi and more (28 kPa)
Supplier number.................................................................................................................................. 286404
Prévost number................................................................................................................................... 641462
Brake Relay Valves
Make............................................................................................................................. Bendix Westinghouse
Model........................................................................................................................................ R-12 & R-12C
Supplier number.................................................................................................................................. 102852
Prévost number................................................................................................................................... 641088
Quick Release Valve
Make............................................................................................................................. Bendix Westinghouse
Model...................................................................................................................................................... QR-1
Supplier number................................................................................................................................ 5001496
Prévost number................................................................................................................................... 641429
Spring Brake Valve
Make............................................................................................................................. Bendix Westinghouse
Model.......................................................................................................................................................SR-1
Supplier number.................................................................................................................................. 286364
Prévost number................................................................................................................................... 640870
Pressure Protection Valve
Make............................................................................................................................. Bendix Westinghouse
Model.......................................................................................................................................................PR-4
Nominal closing pressure......................................................................................................70 psi (482 kPa)
Supplier number.................................................................................................................................. 277226
Prévost number................................................................................................................................... 641137
Shuttle-Type Double Check Valve
Make............................................................................................................................. Bendix Westinghouse
Model.......................................................................................................................................................DC-4
Supplier number.................................................................................................................................. 277988
Prévost number................................................................................................................................... 641015
Low Pressure Indicators
Make............................................................................................................................. Bendix Westinghouse
Model....................................................................................................................................................... LP-3
Contact close ........................................................................................................................66 psi (455 kPa)
Supplier number.................................................................................................................................. 277227
Prévost number................................................................................................................................... 640975
Air Pressure Regulator
Make................................................................................................................................................... Norgren
Adjustable output range ..................................................................................... 0-80/85 psi (0-552/586 kPa)
Recommended pressure setting...........................................................................................75 psi (517 kPa)
Supplier number.................................................................................................................... R06-2G7 RNKA
Prévost number................................................................................................................................... 641472
Air Filter Element
Make................................................................................................................................................... Norgren
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Section 12: BRAKE AND AIR SYSTEM
Type ...................................................................................................................................With manual drain
Supplier number.......................................................................................................................F74G-345-004
Prévost number................................................................................................................................... 641338
Front Axle Brake Chambers
Make..........................................................................................................................................Knorr-Bremse
Type ............................................................................................................................................................ 24
Supplier number (R.H.) ....................................................................................................... BS-3457 II 34671
Prévost number (R.H.) ........................................................................................................................ 641414
Supplier number (L.H.)........................................................................................................ BS-3457 II 34670
Prévost number (L.H.)......................................................................................................................... 641413
Drive Axle Brake Chambers
Make..........................................................................................................................................Knorr-Bremse
Type .............................................................................................................24 as service -24 as emergency
Supplier number..................................................................................................................II/35699/BS-9524
Prévost number................................................................................................................................... 641432
Piggy Back (On Drive Brakes)
Make..........................................................................................................................................Knorr-Bremse
Type .................................................................................................................................... 24 as emergency
Supplier number........................................................................................................................ II/17567/0061
Prévost number................................................................................................................................... 641433
Tag Axle Brake Chambers
Make..........................................................................................................................................Knorr-Bremse
Type ...........................................................................................................16 as service – 16 as emergency
Supplier number............................................................................................................. II/18224/V1-BS9396
Prévost number................................................................................................................................... 641308
Piggy Back (On Tag Brakes)
Make..........................................................................................................................................Knorr-Bremse
Type .................................................................................................................................... 16 as emergency
Supplier number........................................................................................................................ II/18224/0061
Prévost number................................................................................................................................... 641431
Brake Lining (All Axles)
Make..........................................................................................................................................Knorr-Bremse
Supplier number................................................................................................................................. II 33976
Prévost number................................................................................................................................... 611049
Prévost number................................................................................................................................... 641226
ABS ANTILOCK BRAKING SYSTEM (if applicable)
ABS MODULATOR VALVE
Make..................................................................................................................................... Rockwell Wabco
Voltage .....................................................................................................................................................24 V
Supplier number....................................................................................................................... 472 195 006 0
Prévost number................................................................................................................................... 641097
Sensor, Front Axle
Supplier number.......................................................................................................................441 032-572-0
Prévost number................................................................................................................................... 641288
Sensor, Drive Axle (In Wheel End)
Supplier number.......................................................................................................................441 032-576-0
Prévost number................................................................................................................................... 641095
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D-2 GOVERNOR
COVER
EXHAUST
PORT
UNLOADER
PORTS (3)
RESERVOIR
PORTS (3)
*FORMERLY SD-01-16
16
UPPER SPRING
SEAT
1
RETAINING
RING
17
PRESSURE SETTING
SPRING
4
ADJUSTING
SCREW
14
RETAINING
RING
3
LOCKNUT 11
PISTON
2
BODY
19 LOWER
SPRING SEAT
18
SPRING GUIDE
19 LOWER
SPRING SEAT
8 O-RING
MOUNTING
HOLES
(2)
12 O-RING
5
EXHAUST
STEM
8
O-RING
9
INLET/EXHAUST
VALVE SPRING
10
INLET/EXHAUST
VALVE
15
RETAINING
RING
FIGURE 1 - D-2 GOVERNOR
11
PISTON
6
EXHAUST
STEM
7
FILTERS
13
WASHER 12
O-RING
10
INLET/
EXHAUST
VALVE
9
INLET/EXHAUST
COVER VALVE
SPRING
15
RETAINING
RING
BLUE
NONMETALIC
CLEAR
NONMETALIC
WITH O-RING
BLACK
RUBBER
5
11
11
5
20
O-RING
FIGURE 2 - TYPES OF COVERS
DESCRIPTION
The D-2 Governor, operating in conjunction with the unloading mechanism, automatically controls the air pressure in the air brake or air supply system between a maximum (cutout) pressure and a minimum (cut-in) pressure. The compressor runs continually while the engine runs, but the actual compression of air is controlled by the governor actuating the compressor unloading mechanism which stops or starts the compression of air when the maximum or minimum reservoir pressures are reached.
15
NONMETALIC METALIC
FIGURE 3 - TYPES OF PISTONS
D-2 governors are provided with mounting holes which allow direct mounting to the compressor or remote mounting.
Porting consists of three reservoir ports (1/8 inch P.T.), three unloader ports (1/8 inch P.T.) and one exhaust port (1/
8 inch P.T.).
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OPERATION
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Reservoir air pressure enters the D-2 Governor at one of its reservoir ports and acts on the piston and inlet/exhaust valve.
As the air pressure builds up, the piston and valve move together against the resistance of the pressure setting spring.
When the reservoir air pressure reaches the cut-out setting of the governor, the exhaust stem seats on the inlet/exhaust valve, closing the exhaust passage, and then opens the inlet passage. Reservoir air pressure then flows around the inlet valve, through the passage in the piston and out the unloader port to the compressor unloading mechanism. Air also flows around the piston which is slightly larger at the upper end. The added force resulting from this larger area assures a positive action and fully opens the inlet valve.
As the system reservoir air pressure drops to the cut-in setting of the governor, the force exerted by the air pressure on the piston will be reduced so that the pressure setting spring will move the piston down. The inlet valve will close and the exhaust will open. With the exhaust open, the air in the unloader line will escape back through the piston, through the exhaust stem and out the exhaust port.
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adjusting stem has been sheared off, this is a nonserviceable governor and must be replaced with a new or remanufactured unit.
A. Remove the top cover from the governor.
B. Loosen the adjusting screw locknut.
C.
To raise the pressure settings, turn the adjusting screw counter-clockwise. To lower the pressure settings, turn the adjusting screw clockwise. Note: Be careful not to overadjust. Each 1/4 turn of the adjusting screw raises or lowers the pressure setting approximately 4 psi.
D. When proper adjustment is obtained, tighten the adjusting screw locknut and replace the cover.
( Note : The pressure range between cut-in and cut-out is not adjustable.)
LEAKAGE TEST
Leakage tests on the D-2 governor should be made in both cut-in and cut-out positions.
CUT-IN POSITION
PREVENTIVE MAINTENANCE
Important Note: Review the warranty policy before performing any intrusive maintenance procedures. An extended warranty may be voided if intrusive maintenance is performed during this period.
Apply soap solution around the cover and to the exhaust port. Slight bubble leakage permitted. Excessive leakage indicates a faulty inlet valve or lower piston o-ring.
CUT-OUT POSITION
Every 6 months, 50,000 miles or 1800 operating hours, perform operating and leakage tests.
SERVICE TESTS
Apply soap solution around the cover and to the exhaust port. Slight bubble leakage permitted. Excessive leakage indicates a faulty exhaust valve seat, exhaust stem o-ring, or o-ring at the top of the piston.
OPERATING TESTS
If the governor does not function as described or leakage is excessive, it is recommended that it be replaced with a new or remanufactured unit, or repaired with genuine Bendix parts available at authorized Bendix parts outlets.
Start the vehicle engine and build up air pressure in the air brake system and check the pressure registered by a dash or test gauge at the time the governor cuts-out, stopping the compression of air by the compressor. The cut-out pressure should be in accordance with the pressure setting of the piece number being used. (Common cut-out pressures are between 105-125 psi.) With the engine still running, make a series of brake applications to reduce the air pressure and observe at what pressure the governor cuts-in the compressor. As in the case of the cut-out pressure, the cutin pressure should be in accordance with the pressure setting of the piece number being used. (Common cutting pressures are between 90-105 psi.)
Never condemn or adjust the governor pressure settings unless they are checked with an accurate test gauge or a dash gauge that is registering accurately. If the pressure settings of the D-2 Governor are inaccurate or it is necessary that they be changed, the adjustment procedure follows.
Note: If the governor cover is marked nonadjustable and the
IMPORTANT! PLEASE READ:
When working on or around air brake systems and components, the following precautions should be observed:
1. Park the vehicle on a level surface, apply the parking brakes, and always block the wheels.
2. Stop the engine when working around the vehicle.
3. If the vehicle is equipped with air brakes, make certain to drain the air pressure from all reservoirs before beginning any work on the vehicle.
4. Following the vehicle manufacturers recommended procedures, deactivate the electrical system in a manner that removes all electrical power from the vehicle.
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5. When working in the engine compartment the engine should be shut off. Where circumstances require that the engine be in operation, extreme caution should be used to prevent personal injury resulting from contact with moving, rotating, leaking, heated, or electrically charged components.
6. Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a component or plug unless you are certain all system pressure has been depleted.
7. Never exceed recommended pressures and always wear safety glasses.
8. Do not attempt to install, remove, disassemble or assemble a component until you have read and thoroughly understand the recommended procedures. Use only the proper tools and observe all precautions pertaining to use of those tools.
9. Use only genuine Bendix replacement parts, components, and kits. Replacement hardware, tubing, hose, fittings, etc. should be of equivalent size, type, and strength as original equipment and be designed specifically for such applications and systems.
10. Components with stripped threads or damaged parts should be replaced rather than repaired.
Repairs requiring machining or welding should not be at tempted unless specifically approved and stated by the vehicle or component manufacturer.
11. Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition.
hand grip cover from the top and pull up with thumb until cover disengages from the governor body. If top cover on governor is made of rubber or clear nonmetallic material unscrew cover until it releases from the adjusting screw
(4) of governor. Remove o-ring (20, Figure 2) if present.
Note: O-ring (20) is used on Hi-Temp and waterproof governors only.
4. With a pair of retaining ring pliers, remove the spring assembly retaining ring (1) and save.
5. Pull the adjusting screw (4) and spring assembly out of the governor body (2).
Note: Disassembly of the spring assembly normally is not required. (Reuse and do not wash the assembly because lubrication may be removed.) If Disassembly of the spring assembly is necessary, the following instructions apply; otherwise, proceed to Step 6.
Remove the lock nut (3), then the hex-shaped upper spring seat (16) from the adjusting screw (4). Remove the pressure setting spring (17), lower spring seat (19), spring guide (18) and the other lower spring seat (19) from the adjusting screw (4).
6. Gently tap the open end of the valve body on a flat surface to remove the exhaust stem (5), the exhaust stem spring (6), and piston assembly (11). Items 5 and 11 may be made of metal or nonmetallic material.
7. Remove and discard the two o-rings (8) on the piston
O.D. and with a hooked wire remove and discard the oring (12) from the piston l.D. On nonmetallic piston, washer (13) and retaining ring (14) may be removed to facilitate removal of o-ring (12).
REMOVING AND INSTALLING
REMOVING
1. Block and hold vehicle by means other than air brakes.
2. Drain air brake system.
3. If the governor is compressor-mounted type, disconnect reservoir air line. If the governor is remote- mounted, disconnect both the unloader and reservoir air lines.
4. Remove governor mounting bolts, then governor.
Caution: Prior to disassembly, it is required to have the proper maintenance kit available to replace parts to be discarded during disassembly.
8. If piston assembly is nonmetallic (Figure 3), use a small screwdriver and carefully insert blade of screwdriver between two of the ears of the retainer ring in the bottom of the piston (11) and pry retainer ring (15) out of the piston and discard. Remove inlet/exhaust valve spring (9) and the inlet/exhaust valve (10) and discard. If piston assembly is metallic, disengage inlet/exhaust valve spring
(9) from recess in bottom of piston (11), remove inlet/ exhaust valve spring (9), and the inlet exhaust valve (10) and discard.
9. Remove and discard filters (7) from unloader and reservoir ports in governor body.
CLEANING AND INSPECTION
DISASSEMBLY
1. Clean the governor exterior of dirt and grease.
2. If the governor cover is marked nonadjustable and the adjusting screw has been sheared off, this is a nonserviceable governor and must be replaced with a new or remanufactured unit.
3. If the governor has a blue nonmetallic cover, (refer to
Figure 2) hold governor with one hand, with the other
1. Clean all remaining parts in mineral spirits.
2. Inspect body for cracks or other damage. Be particularly careful that all air passages in the body, exhaust stem, and piston are not obstructed.
3. Check springs for cracks, distortion, or corrosion.
4. Replace all parts which are worn or damaged.
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ASSEMBLY
possible.
Note: main m e n u during disassembly.
tom of the piston (11).
Metallic Piston: piston (11).
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Prior to assembly, lubricate the two lower body bores, all orings and o-ring grooves with lubricant provided. Note: Also spring guide and adjusting screw (if disassembled).
1. Install o-ring (12) in piston (11). Replace washer (13) and retaining ring (14) on nonmetallic piston if removed
2. Drop the inlet/exhaust valve (10) into place at the bot-
3.
Nonmetallic Piston: Install the inlet/exhaust valve spring
(9) with the small end against the valve, place the retaining ring (15) on top of the large end of the valve spring (9)
[concave side of retaining ring (15) facing away from piston (11)], press into piston with thumb, making sure ears of retaining ring (15) are seated into piston (11) as far as
Do not use a press or hammer to install retaining ring. Excessive force may damage the piston.
Install the inlet/exhaust valve spring
(9) with the small end against the valve. Press the spring down until the larger coiled end snaps into the recess inside the piston (11).
4. Install the piston o-rings (8) on the piston (11).
5. Install the exhaust stem spring (6) in the piston (11) with the large coil end next to the piston.
6. Install the exhaust stem (5) through spring (6) and into
7. Install assembled piston (11) into the governor body (2).
8. If the spring assembly was not disassembled, proceed to Step 9. If the spring assembly was disassembled, the following instructions apply: install on the adjusting screw (4) in this order; lower spring seat (19), spring guide (18), spring seat (19), pressure setting spring (17), hex-shaped upper spring seat (16). Screw the upper spring seat onto the adjusting screw until the distance from the top of the seat to the bottom of the adjusting global search
screw head is approximately 1-7/8 inches. Install the lock nut (3).
9. Install the adjusting screw (4) and spring assembly into the governor body (2).
10. Install retaining ring (1) making certain that it seats completely into the groove in the governor body (2).
If cover provided in kit is black rubber, (refer to Figure 2) install by pushing it onto the adjusting screw.
If cover provided in kit is clear nonmetallic, install o-ring
(20) and screw cover onto the adjusting screw. Tighten until cover bottoms on governor body. Note: O-ring (20) is used only on Hi-Temp and waterproof governors. If cover provided in kit is blue nonmetallic place cover over one edge of top of governor; with index finger catch knob on top of cover and pull until cover snaps into place.
Note: Nonmetallic cover should be at room temperature for ease of assembly. Do not attempt to force cover on square to the governor body.
12. Install filters (7) in governor body. The head of a pencil makes a satisfactory installation tool.
INSTALLATION
1. If the governor is compressor-mounted, clean the mounting pad on both the compressor and governor. Clean connecting line, or lines. Be certain the unloading port is clear and clean. If the governor is mounted remotely, it should be positioned so that its exhaust port points down. It should be mounted higher than the compressor so that its connecting lines will drain away from the governor.
2. Install governor.
3. If compressor-mounted type, use the governor mounting gasket provided.
4. Connect air lines to governor.
5. Perform operating and leakage tests as outlined under
Service Tests section.
4
BW1425 © AlliedSignal Truck Brake Systems 1/1999 Printed in U.S.A.
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TU-FLO 750 COMPRESSOR
DISCHARGE
VALVE STOP
DISCHARGE
VALVE
DISCHARGE
VALVE SEAT
CRANKCASE
PISTON RINGS
CONNECTING
ROD
UNLOADER
COVER
DISCHARGE
VALVE SPRING
PISTON
AIR DISCHARGE
WATER
INLET
GOVERNOR
MOUNTING
PAD
CYLINDER
HEAD
WATER OUTLET
AIR INLET
CRANKCASE
CRANKSHAFT
BENDIX TU-FLO 750 COMPRESSOR
(CROSS SECTION)
DESCRIPTION
The function of the air compressor is to provide and maintain air under pressure to operate devices in the air brake and/or auxiliary air systems. The Tu-Flo 650 compressor is a two cylinder single stage, reciprocating compressor with a rated displacement of 16.5 cubic feet per minute at 1250
RPM.
The compressor assembly consists of two major subassemblies, the cylinder head and the crankcase. The cylinder head is an iron casting which houses the inlet, discharge, and unloader valving. (See Figure 1.) The cylinder head contains the air inlet port and is designed with both top and side air discharge ports. Three water coolant ports provide a choice of coolant line connections. Governor mounting surfaces are provided at both the front and the rear of the cylinder head. The head is mounted on the crankcase and is secured by six cap screws. The Tu-Flo
750 compressor is designed such that the cylinder head can be installed in one of two positions which are 180 degrees apart. The crankcase houses the cylinder bores, pistons, crankshaft and main bearings, and provides the flange or base mounting surface.
CYLINDER
HEAD
BENDIX TU-FLO 750 COMPRESSOR
(EXTERIOR)
UNLOADER
END VIEW OF CYLINDER HEAD
PIECE NO.
TAG
INLET VALVE
INLET VALVE
SEAT
INLET
INLET VALVE
SPRING
1
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AIR DISCHARGE
WATER
FIGURE 1 - CYLINDER HEAD local search global search
UNLOADER COVER
PLATE
AIR
DISCHARGE
WATER
AIR INLET
GOVERNOR
MOUNTING
PAD
WATER
CAT MACK
(MACK STYLE)
MACK
EXTENDED
MACK
"FOXHEAD"
CUMMINS DETROIT
DIESEL
FIGURE 2 - MOUNTING CONFIGURATIONS
Various mounting and drive configurations, as shown in Figure 2, are supplied as required by the vehicle engine designs.
A nameplate identifying the compressor piece number and serial number is attached to the side of the crankcase. (Reference Figure 3.)
TU-FLO 750 COMPRESSOR
BENDIX NO.
SERIAL NO.
MANUFACTURED BY BENDIX
FIGURE 3 - NAMEPLATE
OPERATION
The compressor is driven by the vehicle engine and is operating continuously while the engine is running. Actual compression of air is controlled by the compressor unloading mechanism and the governor. The governor which is generally mounted on the compressor maintains the brake
2 system air pressure to a preset maximum and minimum pressure level.
INTAKE AND COMPRESSION OF AIR (LOADED)
During the down stroke of the piston, a slight vacuum is created between the top of the piston and the cylinder head, causing the inlet valve to move off its seat and open. (Note:
The discharge valve remains on its seat.) Atmospheric air is drawn through the air strainer and the open inlet valve into the cylinder (see Figure 4). As the piston begins its upward stroke, the air that was drawn into the cylinder on the down stroke is being compressed. Air pressure on the inlet valve plus the force of the inlet spring, returns the inlet valve to its seat and closes. The piston continues the upward stroke and compressed air pushes the discharge valve off its seat and air flows by the open discharge valve, into the discharge line and to the reservoirs (see Figure 5). As the piston reaches the top of its stroke and starts down, the discharge valve spring and air pressure in the discharge line returns the discharge valve to its seat. This prevents the compressed
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AIR
DISCHARGE
PORT local search
GOVERNOR
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DISCHARGE
PORT
UNLOADER
PISTON
GOVERNOR
PORT
DISCHARGE
VALVE
CLOSED
INLET
VALVE
OPEN
AIR
INLET
PORT
PISTON
MOVING
DOWN
DISCHARGE
VALVE
CLOSED
AIR
INLET
PORT
INLET VALVE
HELD OPEN
BY UNLOADER
PISTON
FIGURE 4 - OPERATIONAL-LOADED (INTAKE)
AIR
DISCHARGE
PORT
GOVERNOR
PORT
DISCHARGE
VALVE
OPEN
INLET
VALVE
CLOSED
AIR
INLET
PORT
MOVING
UP
FIGURE 6 - OPERATIONAL-UNLOADED ernor closes and exhausts the air from above the unloader pistons. The unloader springs force the pistons upward and the inlet valves return to their seats. Compression is then resumed.
LUBRICATION
The vehicle's engine provides a continuous supply of oil to the compressor. Oil is routed from the engine to the compressor oil inlet. An oil passage in the compressor crankshaft allows oil to lubricate the connecting rod crankshaft bearings. Connecting rod wrist pin bushings and crankshaft ball bearings are spray lubricated. An oil return line connected from the compressor drain outlet to the vehicle engine crankcase allows for oil return. On flange mounted models the oil drains back directly to the engine through the mounting flange.
FIGURE 5 - OPERATIONAL-LOADED (COMPRESSION) air in the discharge line from returning to the cylinder bore as the intake and compression cycle is reseated.
NON-COMPRESSION OF AIR (UNLOADED)
When air pressure in the reservoir reaches the cut-out setting of the governor, the governor allows air to pass from the reservoir, through the governor and into the cavity above the unloader pistons. The unloader pistons move down holding the inlet valves off their seats (see Figure 6.) With the inlet valves held off their seats by the unloader pistons, air is pumped back and forth between the two cylinders, and the discharge valves remain closed. When air pressure from the reservoir drops to the cut-in setting of the governor, the gov-
OIL
OUTLET
OIL
INLET
FIGURE 7 - LUBRICATION (BASE MOUNT MODEL SHOWN)
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COOLING
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Air flowing through the engine compartment from the action of the engines fan and the movement of the vehicle assists in cooling the compressor. Coolant flowing from the engines cooling system through connecting lines enters the head and passes through internal passages in the cylinder head and is returned to the engine. Proper cooling is important in maintaining discharge air temperatures below the maximum recommended 400 degrees Fahrenheit.
Figure 8 illustrates the various approved coolant flow connections. See the tabulated technical data in the back of this manual for specific requirements.
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If a previously unturbocharged compressor is being turbocharged, it is recommended that the inlet cavity screen
(238948) be installed with an inlet gasket (291909) on both sides of the screen.
COMPRESSOR TURBOCHARGING
PARAMETERS
Air entering the compressor inlet during the loaded cycle must not exceed 250 degrees Fahrenheit (121 degrees Celsius). A metal inlet line is suggested to help meet this parameter.
The following compressor crankshaft rotative speed and inlet pressure relationships may not be exceeded.
WATER
IN
WATER
OUT
Crankshaft Maximum Compressor R.P.M.
Inlet Pressure
30.0 psi (207 kPa)
27.5 psi (190 kPa)
24.0 psi (165 kPa)
21.0 psi (145 kPa)
19.0 psi (131 kPa)
16.0 psi (110 kPa)
OR
(1 PORT
ONLY)
1900 RPM
2000 RPM
2100 RPM
2200 RPM
2300 RPM
2400 RPM
WATER OUT
FIGURE 8 - COOLING
WATER
IN
WATER
IN
OR
(1 PORT
ONLY)
AIR INDUCTION
There are three methods of providing clean air to the Tu-Flo
750 compressor:
1. Naturally aspirated - Compressor utilizes its own attached air strainer (polyurethane sponge or pleated paper dry element).
2. Naturally aspirated - Compressor inlet is connected to the engine air cleaner or the vacuum side (engine air cleaner) of the supercharger or turbocharger.
3. Pressurized induction - Compressor inlet is connected to the pressure side of the supercharger or turbocharger.
See the tabulated technical data in the back of this manual
35
30
25
20
15
10
5
0
600 900 1200 1500 1800 2100 2400
Compressor Speed (RPM)
Turbo Limits
FIGURE 9 - TURBO LIMITS CURVE
2700
PREVENTATIVE MAINTENANCE
Important Note: Review the warranty policy before performing any intrusive maintenance procedures. An extended warranty may be voided if intrusive maintenance is performed during this period.
AIR INDUCTION
One of the single most important aspects of compressor preventive maintenance is the induction of clean air. The type and interval of maintenance required will vary depending upon the air induction system used.
The intervals listed under the headings below pertain to typical highway and street operation. More frequent maintenance will be required for operation in dusty or dirty environments.
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POLYURETHANE SPONGE STRAINER
PAPER AIR STRAINER DRY ELEMENT-PLEATED
FIGURE 10 - STRAINERS
POLYURETHANE SPONGE STRAINER
Every month, 150 operating hours or 5,000 miles, whichever occurs first, remove and wash all of the parts. The strainer element should be cleaned or replaced. If the element is cleaned, it should be washed in a commercial solvent or a detergent and water solution. The element should be saturated in clean engine oil, then squeezed dry before replacing it in the strainer. Be sure to replace the air strainer gasket if the entire strainer is removed from the compressor intake.
DRY ELEMENT - PLEATED PAPER STRAINER
Every two months, 800 operating hours or 20,000 miles whichever occurs first, loosen the spring clip from the unhinged side of the mounting baffle and open the cover.
Replace the pleated paper filter and secure the cleaned cover, making sure the filter is in position. Be sure to replace the air strainer gasket if the entire air strainer is removed from the compressor intake.
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INTAKE ADAPTER
When the engine air cleaner is replaced: Some compressors are fitted with compressor intake adapters, which allow the compressor intake to be connected to the engine air induction system. In this case, the compressor receives a supply of clean air from the engine air cleaner. When the engine air filter is changed, the compressor intake adapter should be checked. If it is loose, remove the intake adapter, clean the strainer plate, if applicable, and replace the intake adapter gasket, and reinstall the adapter securely. Check line connections both at the compressor intake adapter and at the engine. Inspect the connecting line for ruptures and replace it if necessary.
COMPRESSOR COOLING
Every 6 months, 1800 operating hours or after each
50,000 miles whichever occurs first, inspect the compressor discharge port, inlet cavity and discharge line for evidence of restrictions and carboning. If excessive buildup is noted, thoroughly clean or replace the affected parts and closely inspect the compressor cooling system. Check all compressor coolant lines for kinks and restrictions to flow.
Minimum coolant line size is 3/8" I.D. Check coolant lines for internal clogging from rust scale. If coolant lines appear suspicious, check the coolant flow and compare to the tabulated technical data present in the back of this manual.
Carefully inspect the air induction system for restrictions.
LUBRICATION
Every six months, 1800 operating hours or 50,000 miles which ever occurs first, check external oil supply and return lines, if applicable, for kinks, bends, or restrictions to flow. Supply lines must be a minimum of 3/16" I.D. and return lines must be a minimum of 1/2" I.D. Oil return lines should slope as sharply as possible back to the engine crankcase and should have as few fittings and bends as possible. Refer to the tabulated technical data in the back of this manual for oil pressure minimum values
COMPRESSOR DRIVE
Every six months, 1800 operating hours or 50,000 miles, whichever occurs first, check for noisy compressor operation, which could indicate a worn drive gear coupling, a loose pulley or excessive internal wear. Adjust and/or replace as necessary.
If the compressor is belt driven, check for proper belt and pulley alignment and belt tension. Check all compressor mounting bolts and retighten evenly if necessary. Check for leakage and proper unloader mechanism operation. Repair or replace parts as necessary.
Every 24 months, 7200 operating hours, or after each
200,000 MILES, perform a thorough inspection, and depend-
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main m e n u local search ing upon the results of this inspection or experience, disassemble the compressor, clean and inspect all parts thoroughly, replace all worn or damaged parts using only genuine Bendix replacements or replace the compressor with a genuine Bendix remanufactured unit.
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der head maintenance kit. Retest the cylinder head after installation of the kit.
REMOVAL AND DISASSEMBLY
GENERAL
GENERAL SERVICE CHECKS
OPERATING TESTS
Vehicles manufactured after the effective date of FMVSS
121, with the minimum required reservoir volume, must have a compressor capable of raising air system pressure from
85-100 psi in 25 seconds or less. This test is performed with the engine operating at maximum recommended governed speed. The vehicle manufacturer must certify this performance on new vehicles with appropriate allowances for air systems with greater than the minimum required reservoir volume.
The following disassembly and assembly procedure is presented for reference purposes and presupposes that a major rebuild of the compressor is being undertaken. Several maintenance kits are available which do not require full disassembly. The instructions provided with these parts and kits should be followed in lieu of the instructions presented here.
REMOVAL
These instructions are general and are intended to be a guide, in some cases additional preparations and precautions are necessary.
AIR LEAKAGE TESTS
Compressor leakage tests need not be performed on a regular basis. These tests should be performed when; it is suspected that discharge valve leakage is substantially affecting compressor build-up performance, or when it is suspected that the compressor is cycling between the load and unloaded modes due to unloader piston leakage.
These tests must be performed with the vehicle parked on a level surface, the engine not running, the entire air system completely drained to 0 P.S.I., and the inlet check valve detail parts removed, if applicable.
UNLOADER PISTON LEAKAGE
The unloader pistons can be checked for leakage as follows: with the cylinder head removed from the compressor and the inlet flange securely covered, apply 120 psi of air pressure to the governor port. Listen for an escape of air at the inlet valve area. An audible escape of air should not be detected.
1. Block the wheels of the vehicle and drain the air pressure from all the reservoirs in the system.
2. Drain the engine cooling system and the cylinder head of the compressor. Identify and disconnect all air, water and oil lines leading to the compressor.
3. Remove the governor and any supporting bracketry attached to the compressor and note their positions on the compressor to aid in reassembly.
4. Remove the discharge and inlet fittings, if applicable, and note their position on the compressor to aid in reassembly.
5. Remove the flange or base mounting bolts and remove the compressor from the vehicle.
6. Remove the drive gear(s) or pulley from the compressor crankshaft using a gear puller. Inspect the pulley or gear and associated parts for visible wear or damage. Since these parts are precision fitted, they must be replaced if they are worn or damaged.
PREPARATION FOR DISASSEMBLY
DISCHARGE VALVE LEAKAGE
Unloader piston leakage must be repaired before this test is performed. Leakage past the discharge valves can be detected as follows: Remove the discharge line and apply shop air back through the discharge port. Listen for an escape of air at the compressor inlet cavity. A barely audible escape of air is generally acceptable.
Remove road dirt and grease from the exterior of the compressor with a cleaning solvent. Before the compressor is disassembled, the following items should be marked to show their relationship when the compressor is assembled. Mark the rear end cover in relation to the crankcase. Mark the base plate or base adapter in relation to the crankcase.
If the compressor does not function as described above or if the leakage is excessive, it is recommended that it be returned to the nearest authorized Bendix distributor for a factory remanufactured compressor. If it is not possible, the compressor can be repaired using a genuine Bendix cylin-
A convenient method to indicate the above relationships is to use a metal scribe to mark the parts with numbers or lines. Do not use marking methods such as chalk that can be wiped off or obliterated during rebuilding.
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CYLINDER
HEAD
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3
2
9
8
6
7
5
4
26
19
15
16
17
18
CRANKCASE 31
10
11
12
13
14
36
30
29
32
31
22
20
NAMEPLATE
38
39
40
21
FIGURE 11 - EXPLODED VIEW
11
12
13
14
7
8
9
10
5
6
3
4
ITEM QTY
1 6
2 4
1
2
4
1
2
2
2
2
2
2
2
2
DESCRIPTION
Cylinder Head Cap Screws
Unloader Plate Cap Screws
Unloader Plate Lock Washers 17
Unloader Plate 18
Unloder Plate Gasket
O-ring
19
20
ITEM
15
16
Unloader
Spring
Unloader Bushing
Gasket
Inlet Valve Seat
Inlet Valve
Inlet Valve Spring
Inlet Valve Stop
25
26
27
28
21
22
23
24
2
4
4
2
6
8
1
6
1
1
2
2
QTY
2
2
DESCRIPTION
Discharge Valve Stop
Discharge Valve Spring
Discharge Valve
Discharge Valve Stop
Cylinder Head Gasket
Base Gasket
Base Plate
Base Plate Cap Screws
Standard Piston Rings
Oil Ring
Expander Ring
Pistion
Wrist Pin
Wrist Pin Button
23
23
24
25
24
27
24
23
25
24
37
BALL BEARING
(MACK EXTENDED
ITEM
29
30
31
32
33
34
35
36
37
38
39
40
28
33 32
32
FLANGE)
34
2
2
4
2
2
4
1
1
2
2
QTY
1
1
35
DESCRIPTION
Crankshaft
Crankshaft Key
Thrust Washer
Sleeve (or Ball) Bearing
End Cover Seal
End Cover
End Cover Cap Screws
Wrist Pin Bushing
Connecting Rod
Conn. RodInserts (Sets)
Connecting Rod Caps
Connecting Rod Bolts
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CYLINDER HEAD
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Remove the six cylinder head cap screws (1) and tap the head with a soft mallet to break the gasket seal. Remove the unloader cover plate cap screws (2), lockwashers (3) and the unloader cover plate (4). Scrape off any gasket material (5) from the cover plate, cylinder head and crankcase.
1. Remove the unloader pistons (7), o-rings (6) and springs
(8).
2. Inspect the unloader piston bushings (9) for nicks, wear, corrosion and scoring. It is recommended that the compressor be replaced if it is determined that the unloader bushing is damaged or worn excessively.
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in the connecting rod. If excessive wear is noted or suspected, replace the connecting rod and piston.
COMPRESSOR CRANKCASE DISASSEMBLY
1. Remove the key or keys (30) from the crankshaft (29) and any burrs from the crankshaft where the key or keys were removed. ( Note: Through drive compressors may have a crankshaft key at both ends.)
2. Remove the four cap screws (35) and lockwashers or nuts and lockwashers that secure the rear end cover
(34) to the crankcase.
3. Remove the rear end cover (34), thrust washer (31) and end cover oil seal ring (33), taking care not to damage the bearing if present in the end cover.
Before disassembling the discharge valve mechanism, measure and record the discharge valve travel (from closed to completely open).
4. If the compressor has ball type main bearings, press the crankshaft (29) and ball bearings from the crankcase, then press the ball bearings from the crankshaft.
3. If the measured discharge valve travel exceeds .046
inches, the compressor should be replaced. If the discharge valve travel does not exceed .046, using a 9/
16" Allen wrench, remove the discharge valve seats (18), valves (17) and valve springs (16).
4. Remove the inlet valve stops (14), valves (17), valve seats
(11), valve springs (12) and gaskets (10). It is recommended that a tool such as a J-25447-B, produced by
Kent Moore Tool Division Roseville, Michigan phone 1-
800-328-6657, be used to remove the inlet valve stop.
5. Press the oil seal out of the compressor crankcase, if so equipped.
CLEANING OF PARTS GENERAL
All parts should be cleaned in a good commercial grade of solvent and dried prior to inspection.
CYLINDER HEAD
CRANKCASE BOTTOM COVER OR ADAPTER
DISASSEMBLY
1. Remove the cap screws (22) securing the bottom cover or adapter (21). Tap with a soft mallet to break the gasket seal. Scrape off any gasket material (20) from the crankcase and bottom cover or adapter.
Remove carbon deposits from the discharge cavity and rust and scale from the cooling cavities of the cylinder head body.
Scrape all foreign matter from the body surfaces and use shop air pressure to blow the dirt particles from the cavities.
Clean carbon and dirt from the inlet and unloader passages.
Use shop air to blow the carbon and dirt deposits from the unloader passages.
OIL PASSAGES
CONNECTING ROD DISASSEMBLY
Before removing the connecting rod, mark the connecting rods (37) and their caps (39) to ensure correct reassembly.
The connecting rod and cap are a matched set therefore the caps must not be switched or rotated end for end.
Thoroughly clean all oil passages through the crankshaft, crankcase, end covers, base plate or base adapter. Inspect the passages with a wire to be sure. Blow the loosened foreign matter out with air pressure.
INSPECTION OF PARTS
1. Remove the connecting rod bolts (40) and bearing caps
(39).
2. Push the pistons (26) with the connecting rods (37) attached out the top of the cylinder bore of the crankcase.
Replace the bearing caps on the connecting rods.
3. Remove the piston rings (23-25) from the piston. If the piston is to be removed from the connecting rod, remove the wrist pin teflon plugs (28) and press the wrist pin
(27) from the piston and connecting rod.
4. If the piston is removed from the rod, inspect the wrist pin bore in the piston and bronze wrist pin bushing (36)
CYLINDER HEAD BODY
Inspect the cylinder head for cracks or damage. With the cylinder head and head gasket secured to a flat surface or crankcase, apply shop air pressure to one of the coolant ports with all others plugged, and check for leakage by applying a soap solution to the exterior of the body. If leakage is detected, replace the compressor.
END COVERS
Check for cracks and external damage. If the crankshaft main bearing (32) is installed in the end cover (34), check for excessive wear and flat spots and replace if necessary.
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CRANKCASE
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Check all crankcase surfaces for cracks and damage. On compressors where ball bearing main bearings are used the difference between the O.D. of the outer race and the I.D. of the crankcase hole should be .0003 in. tight to .0023 in.
loose. This is to maintain the correct fit. The compressor must be replaced if the fit is too loose.
On compressors fitted with precision, sleeve main bearings, the difference between the O.D. of the crankshaft journal and the main bearing l.D. must not exceed .005 in. If the clearance is greater than .005 in. the bearing must be replaced.
The cylinder bores should be checked with inside micrometers or calipers. Cylinder bores which are scored or out of round by more than .0005 in. or tapered more than .0005 in.
should be rebored or honed oversize. Oversized pistons and piston rings are available in .010 in., .020 in. and .030 in.
oversizes. Cylinder bores must be smooth, straight and round. Clearance between the cast iron pistons and cylinder bores should be between .002 in. minimum and .004 in.
maximum.
STANDARD
PISTION
RING
END GAP
SIDE CLEARANCE
.002
.004
EXPANDER
RING
Ring
OIL RING
Compression
Segment
FIGURE 12 - RING CONFIGURATION
PISTON RINGS
Check the pistons for scores, cracks or enlarged ring grooves; replace the pistons if any of these conditions are found.
Measure each piston with a micrometer in relation to the cylinder bore diameter to be sure the diametrical clearance is between .002 in. minimum and .004 in. maximum.
End
Gap
.002
.013
.010
.040
.000
.006
nals on the crankshaft. Check to be sure the oil passages are open through the crankshaft.
Check the fit of the wrist pins to the pistons and connecting rod bushings. The wrist pin should be a light press fit in the piston. If the wrist pin is a loose fit, the piston and pin assembly should be replaced. Check the fit of the wrist pin in the connecting rod bushing by rocking the piston. This clearance should not exceed .0007 in. Replace the connecting rod and cap assembly which includes the wrist pin bushings if excessive clearance is found. Check the fit of the rings in the piston ring grooves. Check the ring gap with the rings installed in the cylinder bores. Refer to Figure 12 for correct gap and groove clearances.
CRANKSHAFT
Check the crankshaft threads, keyways, tapered ends and all machined and ground surfaces for wear, scores, or damage. Standard crankshaft journals are 1.1242 in. - 1.1250 in.
in diameter. If the crankshaft journals are excessively scored or worn or out of round and cannot be reground, the compressor must be replaced. Connecting rod bearing inserts are available in .010 in., .020 in. and .030 in. undersizes for compressors with reground crankshafts. Main bearing journals must be maintained so the ball bearings are a snug fit or so that no more than .005 in. clearance exists between the precision sleeve main bearing and the main bearing jour-
CONNECTING ROD BEARINGS
Used bearing inserts must be replaced. The connecting rod and cap are a matched set and therefore the caps must not be switched or rotated end for end. Make sure the locating tangs on the inserts engage with the locating notches in the rod and cap. Clearance between the connecting rod journal and the connecting rod bearing must not be less than .0003
in. or more than .0021 in. after rebuilding.
REPAIRS
UNLOADER
A new cylinder head maintenance kit should be used when rebuilding. Note: The entire contents of this kit must be used. Failure to do so may result in compressor failure.
The unloader pistons in the kit are prelubricated with a special lubricant piece number 239379 and need no additional lubrication. Install the springs and unloader pistons in their bores being careful not to cut the o-rings. Install the unloader cover gasket and unloader cover and secure the cover cap screws. Tighten the cap screws to 175-225 in.
Ibs. in a crossing pattern after first snugging all screws.
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DISCHARGE VALVES, VALVE STOPS AND
SEATS
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If the discharge valve seats merely show signs of slight wear, they can be dressed by using a lapping stone, grinding compound and grinding tool however it is recommended that a cylinder head maintenance be used. Install new discharge valve springs and valves. Screw in the discharge valve seats, and tighten to 70-90 ft.-lbs. Discharge valve travel should be between .030 in. to .046 in. To test for leakage by the discharge valves, apply 100 psi to the cylinder head discharge port and apply a soap solution to the discharge valve and seats. Leakage in the form of soap bubbles is permissible. If excessive leakage is found, leave the air pressure applied and with the use of a fiber or hardwood dowel and a hammer, tap the discharge valves off their seats several times. This will help the valves to seat and should reduce the leakage. With the air pressure still applied at the discharge port of the cylinder head, check for leakage around the discharge valve stop on the top of the cylinder head casting. No leakage is permitted.
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Install the front thrust washer with the tang inserted in the slot toward the flange. Insert the crankshaft and the rear thrust washer with the tang toward the rear of the compressor.
Place the oil seal ring on the boss of the rear end cover and install the end cover making sure not to pinch the seal ring.
Ensure the tang of the thrust washer is inserted in the slot of the end cover. Fasten the end cover to the crankcase with the four cover cap screws. Torque the cap screws to 175-
225 inch pounds in a cross pattern.
PISTONS AND CONNECTING RODS
If the pistons are to be replaced ensure that the correct pistons are being installed. Note that the pistons for the Tu-
Flo 750 compressor are similar to those of other Bendix compressor models but may be identified by the piston diameter and the distance to the center of the wrist pin from the top of the piston as shown in Figure 13.
PISTON RINGS
INLET VALVES AND SEATS
Inlet valves and springs should be replaced. However, if the inlet valve seats show signs of slight nicks or scratches, they can be redressed with a fine piece of emery cloth or by lapping with a lapping stone, grinding compound and grinding tool. If the seats are damaged to the extent that they cannot be reclaimed, they must be replaced.
ASSEMBLY
Check each ring end gap in a cylinder bore before installation. Place the ring in the top of the cylinder bore and using the piston, push the ring to the midpoint of the cylinder bore and check the ring gap. If the end gaps are incorrect either the wrong repair size has been purchased or the compressor is worn beyond specification and should be replaced.
PISTON COMPARISON
2.78
General Note: All torques specified in this manual are assembly torques and typically can be expected to fall off after assembly is accomplished. Do not retorque after initial assembly torques fall unless instructed otherwise. A compiled listing of torque specifications is presented at the end of this manual.
1.25
1.06
2.17
To convert inch pounds of torque to foot pounds of torque, divide in pounds by 12.
inch pounds ÷ 12 = foot pounds
To convert foot pounds of torque to inch pounds of torque, multiply foot pounds by 12.
foot pounds x 12 = inch pounds
OTHER BENDIX
TU-FLO COMPRESSORS
TU-FLO 750
COMPRESSOR
FIGURE 13 - PISTON COMPARISON
INSTALLING CRANKSHAFT
Press new sleeve bearings in the end cover and crankcase.
Ensure that the slot in the bearings line up with the oil passages in the end cover or crankcase. If you have a model with no oil passage present in the crankcase, press the sleeve bearing into the crankcase with the slot located 90 degrees from vertical.
Install the rings on the pistons per the following instructions starting at the center of the piston and moving outward.
1. Install the spacer and segment rings as follows. Place the spacer ring (25) in the piston groove, the ends of the spacer must butt and not overlap. Install the top segment (24) by inserting one end above the spacer in the ring groove, 120 degrees from the spacer ends and wind the segment into position. Install the bottom segment in the same manner beneath the spacer making sure the gap is staggered 120 degrees from both the top ring segment and the spacer end gaps. Before using be sure
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COMPRESSION RING (23)
SEGMENT RING (24)
SPACER RING (25)
SEGMENT RING (24) global search
BASE PLATE OR BASE ADAPTER
Position the base plate or base adapter gasket (20) on the crankcase and install the base plate or base adapter (21) as marked before disassembly. Tighten the six cap screws
(22), securing the cast iron base adapter evenly to a torque of 175-225 inch pounds for base plate or cover in a crossing pattern after first snugging all 6 screws.
CYLINDER HEAD
Place the cylinder head gasket (19) and cylinder head on the compressor crankcase and install the six cylinder head cap screws. If the cylinder head gasket has a bead on one side, install the gasket on the crankcase with the beaded side up. Snug the cylinder head cap screws prior to torquing the cap screws to 440-500 in. Ibs. in a cross pattern.
Retorque the unloader cover cap screws to 170-225 in. Ibs.
FIGURE 14 - PISTON & RINGS both painted ends of the spacer are visible and butted.
(Refer to Figure 14.)
2. Install the compression rings (23) in the proper grooves with the bevel or pip mark (if any) toward the top of the piston. (Refer to Figure 14.)
Check the ring side clearance of each ring in the piston ring groove. (Refer to Figure 12.) If the side clearance is too large, the piston ring groove is worn beyond specifications and the piston must be replaced.
Rotate the piston rings in their respective groove so that each end gap is at least 90 degrees from the previous rings end gap.
FINAL COMPRESSOR ASSEMBLY
Install all crankshaft keys making certain to support the crankshaft to avoid bearing damage. Install the crankshaft nut where applicable. When installing drive couplings or gears, do not exceed 120 foot pounds torque on the crankshaft nut.
Use covers, plugs, or masking tape to protect all ports if compressor is not to be installed immediately. Protect the ends of the crankshaft against damage by wrapping with masking tape or friction tape.
Lubricate the wrist pin (22) and wrist pin bushing in the connecting rod with engine oil. Assemble the upper portion of the connecting rods and the pistons with the wrist pins.
Insert the wrist pin buttons (28) in the ends of the wrist pin.
Lubricate the pistons and rings with engine oil. Using a ring compression tool return the piston to the cylinder bore.
Turn the crankshaft so that one of its connecting rod journals is in the downward, center position. Install the crankshaft journal bearing segments (38) on the connecting rod (37) and connecting rod cap (39). Tighten the connecting rod bolts (40) evenly and torque to 150 - 170 inch pounds. Install the other connecting rod and piston in the same manner.
It is recommended that new connecting rod cap screws be used.
Before replacing the cylinder head on the crankcase ensure the correct pistons have been used by turning the crankshaft one complete revolution such that each piston moves to its maximum upward stroke. At the maximum upward stroke position each piston should move to the top of the crankcase. If the piston does not approach the top of the crankcase the piston is incorrect and if not replaced could result in compressor damage.
TESTING REBUILT COMPRESSOR
In order to properly test a compressor under operating conditions, a test rack for correct mounting, cooling, lubricating, and driving the compressor is necessary. Such tests are not compulsory if the unit has been carefully rebuilt by an experienced person. A compressor efficiency or build up test can be run which is not too difficult. An engine lubricated compressor must be connected to an oil supply line of at least 15 P.S.I. pressure during the test and an oil return line must be installed to keep the crankcase drained.
Connect to the compressor discharge port, a reservoir with a volume of 1500 cubic inches, including the volume of the connecting line. With the compressor operating at 2100
R.P.M., the time required to raise the reservoir(s) pressure from 85 psi to 100 psi should not exceed 5 seconds. During this test, the compressor should be checked for gasket leakage and noisy operation, as well as unloader operation and leakage.
If the compressor functions as indicated reinstall on the vehicle connecting all lines as marked in the disassembly procedure.
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TU-FLO 750 SPECIFICATIONS
Average weight ............................................................ 53
Number of cylinders ...................................................... 2
Bore size ............................................................. 2.78 In.
Stroke .................................................................. 1.87 In.
Displacement at 1250 RPM.............................. 16.5 CFM
CFM Maximum recommended RPM ............... 2400 RPM
Minimum coolant flow (water cooled) at
Maximum RPM ................................................. 2.5 GPM
Minimum RPM ..................................................... 5 GPM
Approximate horsepower required at
1250 RPM at 120 PSIG (naturally aspirated) .............. 3.2
Turbocharge limits
See Compressor Turbocharging Parameters
Maximum inlet air temperature ............................... 250°F
Maximum discharge air temperature ...................... 400°F
Minimum pressure required to unload
(naturally aspirated) ............................................ 60 PSIG
Minimum oil pressure required at engine idling speed ............................................ 15 PSIG
Minimum oil pressure required at maximum governed engine speed ...................... 15 PSIG
Minimum discharge-line size .............................. 1/2" I.D.
Minimum coolant-line size .................................. 3/8" I.D.
Minimum oil-supply line size ............................. 3/16" I.D.
Minimum oil-return line size................................ 1/2" I.D.
Minimum air-inlet line size .................................... 5/8 I.D.
Minimum unloader-line size ............................... 3/16" I.D.
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(Metric Thread) ..................... 2640 - 3048 (220-254 ft. lbs.)
DIMENSIONAL DATA
Port Sizes
Water inlet ................................................... 1/2 - 14 NPT
Water outlet ................................................. 1/2 - 14 NPT
Air discharge ................................................ 1/2 - 14 NPT
Governor ...................................................... 1/8 - 27 NPT
Oil inlet (end cover) ...................................... 1/8 - 27 NPT
Piston
(standard) ....................................................... 2.77825 in.
(.010 oversize) ................................................ 2.78825 in.
(.020 oversize) ................................................ 2.79825 in.
(.030 oversize) ................................................ 2.80825 in.
Cylinder bore
(standard) ......................................................... 2.7810 in.
(.010 oversize) .................................................. 2.7910 in.
(.020 oversize) .................................................. 2.8010 in.
(.030 oversize) .................................................. 2.8110 in.
MAINTENANCE KITS AND AVAILABLE SERVICE
PARTS
Cylinder Maintenance Kit.
Piston Ring Kit (standard and oversizes.)
Piston and Rod Kit (standard and oversizes.)
Crankshaft Bearing Kit.
TORQUE SPECIFICATIONS
Bolt, Nut or Screw ............................ Assembly Torque
(in. Ibs.)
Cylinder Head .................................................... 440 - 500
Unloader Cover Plate ......................................... 175 - 225
Discharge Valve Seat ............... 840 - 1080 (70-90 ft. Ibs.)
Inlet Valve Stop......................... 840 - 1080 (70-90 ft. Ibs.)
End Cover ......................................................... 175 - 225
Connecting Rod ................................................ 150 - 170
Bottom Cover .................................................... 175 - 225
Air Strainer ........................................................ 125 - 150
Inlet Fitting ........................................................ 175 - 225
Discharge Fitting ............................................... 175 - 225
Governor or Governor Adapter ............................ 175 - 225
Pipe Plugs
1/16 ..................................................................... 35 - 50
1/8 ..................................................................... 85 - 105
1/4 .................................................................... 130 - 170
3/8 .................................................................... 160 - 200
1/2 .................................................................... 200 - 270
Pipe Bushing
1/2 .................................................................... 175 - 225
Crankshaft Nut:
Marsden or Castle ............... 1200 - 1400 (100-120 ft. lbs.)
P/N 298125
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IMPORTANT! PLEASE READ: local search global search
When working on or around a vehicle, the following general precautions should be observed:
1. Park the vehicle on a level surface, apply the parking brakes, and always block the wheels.
2. Stop the engine when working around the vehicle.
3. If the vehicle is equipped with air brakes, make certain to drain the air pressure from all reservoirs before beginning any work on the vehicle.
4. Following the vehicle manufacturers recommended procedures, deactivate the electrical system in a manner that removes all electrical power from the vehicle.
5. When working in the engine compartment the engine should be shut off. Where circumstances require that the engine be in operation, extreme caution should be used to prevent personal injury resulting from contact with moving, rotating, leaking, heated, or electrically charged components.
6. Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a component or plug unless you are certain all system pressure has been depleted.
7. Never exceed recommended pressures and always wear safety glasses.
8. Do not attempt to install, remove, disassemble or assemble a component until you have read and thoroughly understand the recommended procedures. Use only the proper tools and observe all precautions pertaining to use of those tools.
9. Use only genuine Bendix replacement parts, components, and kits. Replacement hardware, tubing, hose, fittings, etc. should be of equivalent size, type, and strength as original equipment and be designed specifically for such applications and systems.
10. Components with stripped threads or damaged parts should be replaced rather than repaired. Repairs requiring machining or welding should not be attempted unless specifically approved and stated by the vehicle or component manufacturer.
11. Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition.
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SYMPTOMS
1. Compressor passes excessive oil as evidenced by presence of oil at exhaust ports of valving or seeping from air strainer.
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COMPRESSOR TROUBLESHOOTING CHART
CAUSE
A. Restricted air intake.
B. Restricted oil return (to engine)
C. Poorly filtered inlet air.
D. Insufficient compressor cooling (compressor runs hot).
REMEDY
A. Check engine or compressor air cleaner and replace if necessary. Check compressor air inlet for kinks, excessive bends and be certain inlet lines have the minimum specified inside diameter. Recommended minimum inlet line inside diameter is 5/8". Recommended maximum air inlet restriction is 25" of water.
B. Oil return to the engine should not be in any way restricted. Check for excessive bends, kinks and restrictions in the oil return line.
Minimum recommended oil return line size is
5/8" O.D. tubing or equivalent l.D. (1/2" minimum). Return line must constantly descend from the compressor to the engine crankcase. Make certain oil drain passages in the compressor and mating engine surfaces are unobstructed and aligned. Special care must be taken when sealants are used with, or instead of, gaskets.
C. Check for damaged, defective or dirty air filter on engine or compressor. Check for leaking, damaged or defective compressor air intake components (e.g. induction line, fittings, gaskets, filter bodies, etc.). The compressor intake should not be connected to any part of the exhaust gas recirculation (E.G.R.) system on the engine.
D.
For air-cooled portions of the compressor:
1. Remove accumulated grease, grime or dirt from the cooling fins. Replace components found damaged.
2. Check for damaged cooling fins. Replace components found damaged.
For water-cooled compressor or water-cooled portions of the compressor:
1. Check for proper coolant line sizes. Minimum recommended size is 1/2" O.D. tubing.
2. Check the coolant flow through the compressor.
Minimum allowable flow is 2.5 gallons per minute at engine governed speed. If low coolant flow is detected, inspect the coolant lines and fittings for accumulated rust scale, kinks and restrictions.
3. Water temperature should not exceed 200 degrees Fahrenheit.
4. Optimum cooling is achieved when engine coolant flows, as shown in Figure 8 of this manual.
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COMPRESSOR TROUBLESHOOTING CHART (Continued)
SYMPTOMS
1. (Continued.)
CAUSE
E. Contaminants not being regularly drained from system reservoirs.
F. Compressor runs loaded an excessive amount of time.
G. Excessive engine crankcase pressure.
H. Excessive engine oil pressure.
I. Faulty compressor.
REMEDY
E. Check reservoir drain valves to insure that they are functioning properly. It is recommended that the vehicle should be equipped with functioning automatic drain valves, or have all reservoirs drained to zero (0) psi daily, or optimally to be equipped with a desiccant-type air dryer prior to the reservoir system.
F. Vehicle system leakage should not exceed industry standards of 1 psi pressure drop per minute without brakes applied and 3 psi pressure drop per minute with brakes applied.
If leakage is excessive, check for system leaks and repair.
G. Test for excessive engine crankcase pressure
& replace or repair ventilation components as necessary. (An indication of crankcase pressure is a loose or partially lifted dipstick.)
H. Check the engine oil pressure with a test gauge and compare the reading to the engine specifications. Bendix does not recommend restricting the compressor oil supply line because of the possibility of plugging the restriction with oil contaminants. Minimum oil supply line size is 3/16" I.D. tubing.
I. Replace or repair the compressor only after making certain none of the preceding installation defects exist.
2. Noisy compressor operations.
A. Loose drive gear or pulley.
A. Inspect the fit of the drive gear on pulley on the compressor crankshaft. The pulley on gear must be completely seated and the crankshaft nut must be tight. If the compressor crankshaft surface or its keyway are damaged, it is an indication of loose drive components. If damage to the compressor crankshaft is detected, replace the compressor. When installing the drive gear or pulley, torque the crankshaft nut to the appropriate torque specifications. Do not back off the crankshaft nut to align the cotter pin and castellated nut. (Some compressors do not use castellated nuts.) Do not use impact wrenches.
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COMPRESSOR TROUBLESHOOTING CHART (Continued) troubleshooting
SYMPTOMS
2. (Continued.)
CAUSE
B. Excessively worn drive couplings or gears.
C. Compressor cylinder head or discharge line restrictions.
D. Worn or burned out bearings.
E. Faulty compressor.
REMEDY
B. Inspect drive gear and couplings and engine for excessive wear. Replace as necessary.
(Nonmetallic gears should be replaced when the compressor is changed.)
C. Inspect the compressor discharge port and discharge line for carbon build-up. If carbon is detected, check for proper cooling to the compressor. (See Cause and Remedy (D) under Symptom #1.) Inspect the discharge line for kinks and restrictions. Replace discharge line as necessary.
D. Check for proper oil pressure in the compressor. Minimum required oil pressure; 15 psi engine idling, 15 psi maximum governed engine rpm. Check for excessive oil temperatureshould not exceed 240 degrees
Fahrenheit.
E. Replace or repair the compressor after determining none of the preceding installation defects exist.
3. Excessive build-up and recover time.
Compressor should be capable of building air system from 85-100 psi in 40 seconds with engine at full governed rpm. Minimum compressor performance is certified to meet
Federal requirements by the vehicle manufacturer. Do not downsize the original equipment compressor.
A. Dirty induction air filter.
B. Restricted induction line.
C. Restricted discharge line or compressor discharge cavity.
D. Slipping drive components.
E. Excessive air system leakage.
A. Inspect engine or compressor air filter and replace if necessary.
B. Inspect the compressor air induction line for kinks and restrictions and replace as necessary.
C. Inspect the compressor discharge port and line for restrictions and carbon build-up. If a carbon build-up is found, check for proper compressor cooling. Replace faulty sections of the discharge line.
D. Check for faulty drive gears and couplings and replace as necessary. Check the condition of drive belts and replace or tighten, whichever is appropriate.
E. Test for excessive system leakage and repair as necessary. Use the following as a guide:
Build system pressure to governor cutout and allow the pressure to stabilize for one minute.
Using the dash gauge, note the system pressure and the pressure drop after two minutes.
The pressure drops should not exceed:
1. 2 psi in each reservoir for a single vehicle.
2. 6 psi in each reservoir for a tractor and trailer.
3. 8 psi in each reservoir for a tractor and 2 trailers.
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COMPRESSOR TROUBLESHOOTING CHART (Continued)
SYMPTOMS
3. (Continued.)
CAUSE
F. Sticking unloader pistons.
G. Faulty compressor.
REMEDY
F. Check the operation of the unloading mechanism. Check the proper operation of the compressor air governor. If the governor is operating properly, replace the unloader mechanism. Inspect for bent, linked or blocked tubing leading to or from the governor.
G. Replace or repair the compressor after determining none of the preceding installation defects exist.
4. Compressor fails to unload.
5. Compressor leaks oil.
6. Compressor constantly cycles (compressor remains unloaded for a very short time).
A. Faulty governor or governor installation.
B. Faulty or worn unloader pistons or bores.
A. Damaged mounting gasket.
B. Cracked crankcase or end cover.
C. Loose end cover cap cover.
D. Loose oil supply or return line fittings.
E. Porous compressor casting.
F. Mounting flange or end cover, o-ring or gasket missing, cut or damaged
A. Leaking compressor unloader pistons.
B. Faulty Governor.
A. Test the governor for proper operation and inspect air lines to and from the governor for kinks or restrictions. Replace or repair the governor or its connecting air lines
B. Inspect for worn, dirty or corroded unloader pistons and their bores. Replace as necessary.
A. Check the compressor mounting bolt torque. If the mounting bolt torque is low, replace the compressor mounting gasket before retorquing the mounting bolts.
B. Visually inspect the compressor exterior for cracked or broken components. Cracked or broken crankcases or mounting flanges can be caused by loose mounting bolts. The end cover can be cracked by overtorquing fitting or plugs installed in the end cover. Replace or repair the compressor as necessary.
C. Check the cap screw torques and tighten as necessary.
D. Check the torque of external oil line fittings and tighten as necessary.
E. Replace the compressor if porosity is found.
F. Replace as necessary.
A. Remove the compressor inlet air strainer or fitting. With the compressor unloaded (not compressing air), check for air leakage.
Replace as necessary.
B. Test the governor for proper operation and repair or replace as necessary.
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COMPRESSOR TROUBLESHOOTING CHART (Continued) troubleshooting
SYMPTOMS
6. (Continued.)
CAUSE
C. Excessive system leakage.
REMEDY
C. Test for excessive system leakage as instructed in Symptom #3 Remedy E. Reduce leakage wherever possible.
D. Drain reservoirs.
7. Compressor leaks coolant.
D. Excessive reservoir contaminants.
A. Improperly installed plugs and coolant line fittings.
B. Freeze cracks due to improper antifreeze strength.
C. Faulty compressor
(porous castings).
A. Check torque of fittings and plugs and tighten as necessary. Overtorqued fittings and plugs can crack the head or block casting.
B. Test antifreeze and strengthen as necessary.
Check coolant flow through compressor to assure the proper antifreeze mixture reaches the compressor.
C. If casting porosity is detected, replace the compressor.
8. Compressor head gasket failure.
A. Clear restriction or replace line.
A. Restricted discharge line.
B. Loose head bolts
C. Faulty compressor or head gasket.
B. Tighten evenly to a torque of 25-30 foot pounds.
C. Check for rough or poorly machined head or block surfaces. Replace compressor as necessary.
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20
BW1637 © AlliedSignal Truck Brake Systems Co. 1/1999 Printed in U.S.A.
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E-8P & E-10P DUAL BRAKE VALVES
TREADLE
TREADLE
MOUNTING
PLATE
MOUNTING
PLATE
SUPPLY
VALVE
SUPPLY
(4)
DELIVERY
(4)
DELIVERY
(4)
VALVE
AUXILLIARY
SUPPLY
EXHAUST
FIGURE 1 - E-8P
DESCRIPTION
Refer to Figures 4, 5 and 6 for item numbers referenced in parenthesis.
The E-8P (Figure 1) and E-10P (Figure 2) Dual Brake Valves are floor mounted, treadle operated type brake valves with two separate supply and delivery circuits for service (primary and secondary) braking, which provides the driver with a graduated control for applying and releasing the vehicle brakes.
The E-10P Dual Brake Valve (Figure 2) is similar to the E-8P
Dual Brake Valve except that a metal coil spring (5) housed in an upper body assembly replaces the rubber spring (27) used in the E-8P valve. The use of a metal coil spring (and the upper body assembly) provides greater treadle travel and, therefore, provides the driver with a less sensitive "feel" when making a brake application. The E-10P Dual Brake
FIGURE 2 - E-10P
EXHAUST
Valve is generally used on busses, where smooth brake applications contribute to passenger comfort.
The circuits in the E-8P/E-10P Dual Brake Valves are identified as follows: The No. 1 or primary circuit is that portion of the valve between the spring seat which contacts the plunger and the relay piston; the No. 2 or secondary circuit is that portion between the relay piston and the exhaust cavity.
The primary circuit of the valve is similar in operation to a standard single circuit air brake valve and under normal operating conditions the secondary circuit is similar in operation to a relay valve.
Both primary and secondary circuits of the brake valve use a common exhaust protected by an exhaust diaphragm.
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MV-3
TP-5 TRACTOR
TRAILER
CONTROL
BRAKE
SLACK
SPRING
SLACK
(E-8P OR E-10P)
DUAL BRAKE
QUICK
RELEASE
DOUBLE
CHECK
GOVERNOR
AIR DRYER BP-R1
BOBTAIL
PROPORTIONING
COMPRESSOR
SUPPLY
RESERVOIR
#1 SERVICE
#2 SERVICE
FIGURE 3 - TYPICAL PIPING SCHEMATIC
15
19
16
27
28
23
18
25
26
22
UPPER BODY
SUP - 1
20
30
24
17
33
DEL - 1
31
21
14
LOWER BODY
32
SUP - 2
13
10
11
FIGURE 4 - E-8P SECTIONAL VIEW
2
9
12
BODY ATTACHING
SCREWS
DEL -2
EXHAUST COVER
ATTACHING SCREWS
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OPERATION
local s e a r c h
- Refer to Figure 3
APPLYING: NORMAL OPERATION - NO. 1 OR
PRIMARY CIRCUIT PORTION
When the brake treadle is depressed, the plunger exerts force on the spring seat (26), graduating spring (23), and primary piston (22). The primary piston, which contains the exhaust valve seat, closes the primary exhaust valve. As the exhaust valve closes, the primary inlet valve is moved off its seat allowing primary air to flow out the No. 1 or primary delivery port.
APPLYING: NORMAL OPERATION - NO. 2 OR
SECONDARY CIRCUIT
When the primary inlet valve (33) is moved off its seat, air is permitted to pass through the bleed passage and enters the relay piston cavity. The air pressure moves the relay piston
(20), which contains the exhaust seat, and closes the secondary exhaust valve. As the secondary exhaust valve closes, the inlet valve (13) is moved off its seat allowing the secondary air to flow out the delivery of the same circuit. Because of the small volume of air required to move the relay piston
(20), action of the secondary circuit of the valve is almost simultaneous with the primary circuit portion.
APPLYING: LOSS OF AIR IN THE NO. 2 OR
SECONDARY CIRCUIT
Should air be lost in the No. 2 or secondary circuit, the No.
1 or primary circuit will continue to function as described above under Normal Operation: No.1 or Primary Circuit Portion.
APPLYING: LOSS OF AIR IN THE NO. 1 OR
PRIMARY CIRCUIT
Should air be lost in the primary circuit, the function will be as follows: As the brake treadle is depressed and no air pressure is present in the primary circuit supply and delivery ports, the primary piston (22) will mechanically move the relay piston (20) , allowing the piston to close the secondary exhaust valve and open the secondary inlet valve and allow air to flow out the secondary delivery port.
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BALANCED: NO. 2 OR SECONDARY CIRCUIT
When the air pressure on the delivery side of the relay piston (20) approaches that being delivered on the primary side of the relay piston, the relay piston moves closing the secondary inlet valve and stopping further flow of air from the supply line through the valve. The exhaust remains closed as the secondary delivery pressure balances the primary delivery pressure.
When applications in the graduating range are made, a balanced position in the primary circuit is reached as the air pressure on the delivery side of the primary piston (22) equals the effort exerted by the driver's foot on the treadle. A balanced position in the secondary portion is reached when air pressure on the secondary side of the relay piston (20) closely approaches the air pressure on the primary side of the relay piston.
When the brake treadle is fully depressed, both the primary and secondary inlet valves remain open and full reservoir pressure is delivered to the actuators.
RELEASING: NO. 1 OR PRIMARY CIRCUIT
With the brake treadle released, mechanical force is removed from the spring seat (26), graduating spring (23), and primary piston (22). Air pressure and spring load moves the primary piston, opening the primary exhaust valve, allowing air pressure in the primary delivery line to exhaust out the exhaust port.
RELEASING: NO. 2 OR SECONDARY CIRCUIT
With the brake treadle released, air is exhausted from the primary circuit side of the relay piston (20). Air pressure and spring load move the relay piston, opening the secondary exhaust valve, allowing air pressure in the secondary delivery line to exhaust out the exhaust port.
PREVENTIVE MAINTENANCE
Important: Review the warranty policy before performing any intrusive maintenance procedures. An extended warranty may be voided if intrusive maintenance is performed during this period.
BALANCED: NO. 1 OR PRIMARY CIRCUIT
When the primary delivery pressure acting on the primary piston (22) equals the mechanical force of the brake pedal application, the primary piston (22) will move and the primary inlet valve (33) will close, stopping further flow of air from the primary supply line through the valve. The exhaust valve remains closed preventing any escape of air through the exhaust port.
Because no two vehicles operate under identical conditions, maintenance and maintenance intervals will vary. Experience is a valuable guide in determining the best maintenance interval for any one particular operation.
Visually check for physical damage to the brake valve such as broken air lines and broken or missing parts.
Every 3 months, or 25,000 miles or 900 operating hours:
Clean any accumulated dirt, gravel, or foreign material away from the heel of the treadle, plunger boot, and mounting plate.
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Using light oil, lubricate the treadle roller, roller pin, and hinge pin.
Refer to figures 4, 5 and 6 for item numbers referenced in parenthesis.
Check the rubber plunger boot for cracks, holes or deterioration and replace if necessary. Also, check mounting plate and treadle for integrity.
Apply 2 to 4 drops of oil between plunger and mounting plate - do not over oil!
Every year, or 100,000 miles, or 3,600 operating hours:
Disassemble, clean parts with mineral spirits, replace all rubber parts, or any part worn or damaged. Check for proper operation before placing vehicle in service.
REMOVAL
1. Chock the vehicle wheels or park the vehicle by mechanical means. (Block and hold vehicle by means other than air brakes.) Drain all air system reservoirs.
2. Identify and disconnect all supply and delivery lines at the brake valve.
3. Remove the brake valve and treadle assembly from the vehicle by removing the three cap screws on the outer bolt circle of the mounting plate. The basic brake valve alone can be removed by removing the three cap screws on the inner bolt circle.
SERVICE CHECKS
OPERATING CHECK
Check the delivery pressure of both primary and secondary circuits using accurate test gauges. Depress the treadle to several positions between the fully released and fully applied positions, and check the delivered pressure on the test gauges to see that it varies equally and proportionately with the movement of the brake pedal.
After a full application is released, the reading on the test gauges should fall off to zero promptly. It should be noted that the primary circuit delivery pressure will be about 2 PSI greater than the secondary circuit delivery pressure with both supply reservoirs at the same pressure. This is normal for this valve.
Important: A change in vehicle braking characteristics or a low pressure warning may indicate a malfunction in one or the other brake circuit, and although the vehicle air brake system may continue to function, the vehicle should not be operated until the necessary repairs have been made and both braking circuits, including the pneumatic and mechanical devices, are operating normally. Always check the vehicle brake system for proper operation after performing brake work and before returning the vehicle to service.
LEAKAGE CHECK
1. Make and hold a high pressure (80 psi) application.
2. Coat the exhaust port and body of the brake valve with a soap solution.
3. Leakage permitted is a one inch bubble in 3 seconds. If the brake valve does not function as described above or leakage is excessive, it is recommended that it be replaced with a new or remanufactured unit, or repaired with genuine Bendix parts available at authorized Bendix parts outlets.
DISASSEMBLY
(Figures 4, 5 and 6)
1. If the entire brake valve and treadle assembly was removed from the vehicle, remove the three cap screws securing the treadle assembly to the basic brake valve.
2. Remove the screw (9) securing the exhaust diaphragm
(10) and washer (11) to the exhaust cover (12).
3. Remove the four screws that secure the exhaust cover
(12) to the lower body.
4. Remove the secondary inlet and exhaust valve assembly (13) from the lower body.
5. Remove the four hex head cap screws securing the lower body to the upper body and separate the body halves.
6. Remove the rubber seal ring (14) from the lower body.
7. For E-8P only: While applying thumb pressure to the primary piston (22), lift out and up on the three lock tabs of the primary piston retainer (15).
8. For E-10P only: While depressing spring seat (7), remove retaining ring (8). Remove spring seat (7) and coil spring (5).
Caution: Before proceeding with the disassembly, refer to Figures 3 and 4 and note that the lock nut (16) and stem (17) are used to contain the primary piston return spring (for E-8P: 23, for E-10P: 6), stem spring (19), and the relay piston spring (21). The combined force of these springs is approximately 50 pounds and care must be taken when removing the lock nut as the spring forces will be released. It is recommended that the primary piston and relay piston be manually or mechanically contained while the nut and stem are being removed.
9. Using a 3/8” wrench, hold the lock nut (16) on the threaded end of the stem (17). Insert a screwdriver to restrain the stem, remove the lock nut (16), spring seat, (18) and stem spring (19).
10. For E-10P only: Remove adapter (1) and o-ring (4).
Remove the primary piston (2) from adapter (1) and oring (34) from the primary piston (2).
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19
16
15
27
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18
25
26
22 global s e a r c h
34
2
6
8
7
5
16
18
19
23
UPPER
BODY
UPPER
BODY 1
32
24
20
33
21
31
32
24
20
33 4
21
31
30
30
17
14
LOWER
BODY
13
BODY
ATTACHING
SCREWS
(QTY. 4)
12
10
11
9
EXHAUST
COVER
ATTACHING
SCREWS
(QTY. 4)
FIGURE 5 - E-8P BRAKE VALVE - EXPLODED VIEW
17
14
LOWER
BODY
13
BODY
ATTACHING
SCREWS
(QTY. 4)
12
10
11
9
EXHAUST
COVER
ATTACHING
SCREWS
(QTY. 4)
FIGURE 6 - E-10P BRAKE VALVE - EXPLODED VIEW
5
6 m a i n m e n u local s e a r c h global s e a r c h
m a i n m e n u local s e a r c h global s e a r c h
11. Remove the relay piston (20), relay piston spring (21), primary piston (E-8P: 22, E-10P: 2) and primary piston return spring (E-8P: 23, E-10P: 6) from the upper body.
Use care so as not to nick seats.
12. A small washer (24) will be found in the cavity of the lower side of the primary piston (for E-8P: 22, for E-
10P: 2).
13. For E-8P only: Disassemble the primary piston by rotating the spring seat nut (25) counterclockwise.
Separate the spring seat nut, spring seat (26), and rubber spring (27) and remove the piston o-ring (28).
14. Remove the large and small o-rings (30 & 31) from the relay piston (20).
15. Remove the retaining ring (32) securing the primary inlet and exhaust valve assembly (33) in the upper body and remove the valve assembly.
CLEANING AND INSPECTION
1. Wash all metal parts in mineral spirits and dry.
2. Inspect all parts for excessive wear or deterioration.
3. Inspect the valve seats for nicks or burrs.
4. Check the springs for cracks or corrosion.
5. Replace all rubber parts and any part not found to be serviceable during inspection, use only genuine Bendix replacement parts.
ASSEMBLY
Prior to reassembling, lubricate all o-rings, o-ring grooves, piston bores, and metal to metal moving surfaces with Dow
Corning 55 o-ring lubricant (Bendix piece number 291126).
Note: All torques specified in this manual are assembly torques and can be expected to fall off, after assembly is accomplished. Do not retorque after initial assembly torques fall.
1. Install the primary inlet and exhaust assembly (33) in the upper body and replace the retaining ring (32) to secure it. Be sure the retaining ring is seated completely in its groove.
2. Install the large and small o-rings (30 & 31) on the relay piston (20).
3. For E-8P only: Install o-ring (28) in the primary piston
(22) o-ring groove.
4. For E-8P only: Install the rubber spring (do not lubricate) (27), concave side down in the primary piston (22) and place the spring seat (26), flat side up, over the rubber spring.
5. For E-8P only: Install the primary piston spring seat nut
(25), with its hex closest to the spring seat, and rotate clockwise until the top surface of the spring seat is even with the top surface of the piston. Set aside.
6. Place relay piston spring (21) in concave portion of relay piston (20) and install relay piston through primary inlet/ exhaust assembly (33) into under side of upper body.
7. For E-10P only: Install o-ring (4) on adapter (1) and install adapter on upper body. Install o-ring (34) on primary piston (2).
8. Place screwdriver, blade up, in vise. Insert stem (17) through the relay piston upper body sub assembly, slide this assembly over the blade of the secured screwdriver, engage the screwdriver blade in the slot in the head of the stem.
9. Place the washer (24) over the stem (17) and on top of the relay piston (20).
10. Install primary return spring (E-8P: 23, E-10P: 6) in upper body piston bore.
11. For E-8P only: Install the primary piston rubber spring sub assembly (steps 4 & 5) over the stem, into the upper body piston bore. For E-10P: Install primary piston sub-assembly (reference step 7).
12. Compress piston(s) (For E-8P: the relay piston (20), for
E-10P: the primary and relay pistons (2 & 20)) and retaining ring into the upper body from either side and hold compressed, either manually or mechanically. See the cautionary note under step 8 in the Disassembly section of this manual.
13. Place the stem spring (19) (E-8P: place over the spring seat nut (25)), the spring seat (18) (concave side up) and lock nut (16) on the stem (17). Torque to 20 - 30 inch pounds.
14. For E-8P only: Install the primary piston retainer (15) over the piston, making certain all three lock tabs have engaged the outer lip of the body.
15. For E-10P only: Install coil spring (5), spring seat (7), and retaining ring (8) .
16. Replace the rubber seal ring (14) on the lower body.
17. Install the 4 hex head cap screws securing the lower body to the upper body. Torque to 30 - 60 inch pounds.
18. Install the secondary inlet and exhaust valve assembly
(13) on the lower body.
19. Install the screws that secure the exhaust cover (12) to the lower body. Torque to 20 - 40 inch pounds.
20. Secure the screw (9) holding the exhaust diaphragm
(10) and the diaphragm washer (11) to the exhaust cover
(12). Torque to 5 - 10 inch pounds.
21. Install all air line fittings and plugs making certain thread sealant material does not enter valve.
VALVE INSTALLATION
1. Install the assembled brake valve on the vehicle.
7
m a i n m e n u local s e a r c h global s e a r c h
2. Reconnect all air lines to the valve using the identification made during VALVE REMOVAL step 1.
3. After installing the brake valve assembly, perform the
“OPERATION AND LEAKAGE CHECKS” before placing the vehicle in service.
IMPORTANT: MAINTENANCE PRECAUTIONS
When working on or around a vehicle, the following general precautions should be observed:
1. Park the vehicle on a level surface, apply the parking brakes, and always block the wheels.
2. Stop the engine when working around the vehicle.
3. Drain the air pressure from all reservoirs before beginning ANY work on the vehicle.
4. Following the vehicle manufacturer’s recommended procedures, deactivate the electrical system in a manner that removes all electrical power from the vehicle.
5. When working in the engine compartment the engine should be shut off. Where circumstances require that the engine be in operation, EXTREME
CAUTION should be used to prevent personal injury resulting from contact with moving, rotating, leaking, heated, or electrically charged components.
6. Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a component or plug unless you are certain all system pressure has been depleted.
7. Never exceed recommended pressures and always wear safety glasses.
8. Do not attempt to install, remove, disassemble, or assemble a component until you have read and thoroughly understand the recommended procedures. Use only the proper tools and observe all precautions pertaining to use of those tools.
9. Use only genuine Bendix replacement parts, components, and kits. Replacement hardware, tubing, hose, fittings, etc. should be of equivalent size, type, and strength as original equipment and be designed specifically for such applications and systems.
10. Components with stripped threads or damaged parts should be replaced rather than repaired. Repairs requiring machining or welding should not be attempted unless specifically approved and stated by the vehicle or component manufacturer.
11. Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition.
8
m a i n m e n u local s e a r c h global s e a r c h
BW2066 © AlliedSignal Truck Brake Systems Co. 7/1999. Printed in USA.
9
m a i n m e n u local s e a r c h global s e a r c h
QR AND QR-1 QUICK RELEASE VALVES
QR VALVE
Brake Valve
Port
*Formerly SD-03-69
QR-1 VALVE
Brake Valve
Port
Brake Chamber
Port
Exhaust Port
Brake Chamber
Port
Brake Chamber
Port
Cover
Diaphragm
Diaphragm
Exhaust Port
Brake Chamber
Port
O-Ring
O-Ring Spring
Cover
QR Valve
FIGURE 1
DESCRIPTION
The function of the Quick Release Valve is to speed up the exhaust of air from the air chambers. It is mounted close to the chambers it serves. In its standard configuration the valve is designed to deliver within one (1) psi of control pressure to the controlled device; however, for special applications the valve is available with greater differential pressure designed into the valve.
Reference Figure 1, two styles of Quick Release Valves are available and are functionally the same; the QR valve, which is of older design and utilizes a spring and spring seat, and the QR-1 valve, which in its standard configuration does not employ a spring or spring seat.
(Note: AR-1 Valves with a pressure differential employ a spring and spring seat. )
Porting consists of one (1) brake valve port, two (2) delivery ports and one ( 1 ) exhaust port.
OPERATION
When a brake application is made, air pressure enters the brake valve port; the diaphragm moves down, sealing the
Body
QR-1 Valve exhaust. At the same time, air pressure forces the edges of the diaphragm down and air flows out the delivery port.
When air pressure being delivered (beneath the diaphragm) equals the pressure being delivered by the brake valve (above the diaphragm), the outer edge of the diaphragm will seal against the body seat. The exhaust port is still sealed by the center portion of the diaphragm when the brake valve application is released; the air pressure above the diaphragm is released back through the brake valve exhaust; air pressure beneath the diaphragm forces the diaphragm to rise, opening the exhaust, allowing air in the chambers to exhaust.
PREVENTIVE MAINTENANCE
Every 12 months, 100,000 miles or 3600 operating hours; disassemble valve, wash metal parts in mineral spirits, wipe rubber parts dry. It is recommended that all rubber parts be replaced. Inspect all parts and replace any part showing signs of wear or deterioration.
OPERATING AND LEAKAGE TESTS
While holding a foot brake valve application:
1
m a i n m e n u local s e a r c h global s e a r c h
2
1. Coat exhaust port with soap solution; leakage of a one
(1) inch bubble in three (3) seconds is permitted.
2. Coat body and cover with soap solution. No leakage perm itted between body and cover.
If the valve does not function as described, or if leakage is excessive, it is recommended that it be replaced with a new or remanufactured unit, or repaired with genuine Bendix parts.
REMOVING AND INSTALLING
REMOVING
Block vehicle wheels and/or hold vehicle by means other than air brakes.
Drain all air brake system reservoirs.
Disconnect air lines from valve.
Remove mounting bolts, then valve.
INSTALLING
Mount valve with exhaust port pointing down; securely tighten mounting bolts.
Connect air lines to valve (brake valve application line to top port; brake chamber line to side ports.)
DISASSEMBLY
QR VALVE
1. Using wrench on square portion of exhaust port, remove cover.
2. Remove spring, spring seat and diaphragm. Remove cover
O-Ring.
QR-1 VALVE
1. Remove four screws.
2. Remove spring and spring seat {if so equipped).
3. Remove diaphragm.
4. Remove cover O-Ring.
CLEANING AND INSPECTION
Clean all metal parts in mineral spirits. Wipe all rubber parts clean.
It is recommended that all rubber parts and any other part showing signs of wear or deterioration be replaced with genuine Bendix parts.
ASSEMBLY
QR VALVE
1. Position spring seat over the diaphragm and then install into body.
2. Install spring and cover O-Ring.
3. Install cover; tighten securely. (Torque to 150-400 inch pounds. )
QR-1 VALVE
1. If valve is equipped within spring and spring seat: a. Position spring in body.
b. Position diaphragm over spring seat.
c. Install O-Ring in cover groove; install cover and tighten screws evenly and securely. (Torque to 30-60 inch pounds.)
2. If valve is not equipped with spring and spring seat: a. Install diaphragm.
b. Install O-Ring in cover groove; install cover and tighten screws evenly and securely. (Torque to 30-60 inch pounds.)
3. Perform tests as outlined in “Operating and Leakage
Tests” section.
IMPORTANT! PLEASE READ
When working on or around a vehicle, the following general precautions should be observed:
1. Park the vehicle on a level surface, apply the parking brakes, and always block the wheels.
2. Stop the engine when working around the vehicle.
3. If the vehicle is equipped with air brakes, make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle.
4. Following the vehicle manufacturer’s recommended procedures, deactivate the electrical system in a manner that removes all electrical power from the vehicle.
5. When working in the engine compartment the engine should be shut off. Where circumstances require that the engine be in operation, EXTREME CAUTION should be used to prevent personal injury resulting from contact with moving, rotating, leaking, heated, or electrically charged components.
6. Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a component or plug unless you are certain all system pressure has been depleted.
7. Never exceed recommended pressures and always wear safety glasses.
8. Do not attempt to install, remove, disassemble or assemble a component until you have read and thoroughly understand the recommended procedures.
Use only the proper tools and observe all precautions pertaining to use of those tools.
9. Use only genuine Bendix replacement parts, components, and kits. Replacement hardware, tubing, hose, fittings, etc. should be of equivalent size, type, and strength as original equipment and be designed specifically for such applications and systems.
10. Components with stripped threads or damaged parts should be replaced rather than repaired. Repairs requiring machining or welding should not be attempted unless specifically approved and stated by the vehicle or component manufacturer.
11. Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition.
BW1442 © AlliedSignal Truck Brake Systems Co. 1/1999. Printed in USA.
R-12 & R-14 RELAY VALVES
SERVICE (1)
* FORMERLY SD-03-31
DELIVERY
EXTERIOR R-12H
SUPPLY (2)
SERVICE (1)
DELIVERY
EXTERIOR R-14H
SUPPLY (2)
EXTERIOR R-12V
FIGURE 1 - EXTERIOR VIEWS
DESCRIPTION
The Relay Valve in an air brake system functions as a relay station to speed up the application and release of the brakes. The valve is normally mounted at the rear of the vehicle in proximity to the chambers it serves. The valve operates as a remote controlled brake valve that delivers or releases air to the chambers in response to the control air delivered to it from the foot brake valve or other source.
EXTERIOR R-14V
The R-12 and R-14 Relay Valves are designed for either reservoir or frame mounting. A universal mounting bracket is furnished that permits easy interchange with other Bendix relay valves. Both valves are available in the two body styles illustrated in Figure 1. The R-14 differs from the R-
12 in that it incorporates a quick release and anti-compounding feature located above its horizontal service port. The R-14s anti-compound feature allows it
1
EXHAUST COVER
BALANCE/QUICK EXHAUST PORT
(ANTI-COMPOUND)
EXHAUST
SEAT
RELAY
PISTON
EXHAUST
SEAT
INLET/
EXHAUST
ASSEMBLY
R-14H
DIAPHRAGM
RELAY
PISTON
EXHAUST
PORT
INLET
EXHAUST
VALVE
ASSEMBLY
EXHAUST
PORT
R-12V
FIGURE 2 - SECTIONAL VIEWS
RETAINING
RING RETAINING
RING to be conveniently used as either a service or spring brake relay valve. An exhaust cover is installed that protects the
1/8" balance port when the R-14 anti-compound feature is not in use.
All parts are interchangeable between the R-12 and R-14 with the exception of the detail components of the R-14 cover. Both valves make extensive use of non-metallic internal components. For ease of servicing, the inlet/ exhaust valve can be replaced without the need for line removal.
OPERATION
APPLICATION
Air pressure delivered to the service port enters the small cavity above the piston and moves the piston down. The exhaust seat moves down with the piston and seats on the inner or exhaust portion of the inlet/exhaust valve, sealing off the exhaust passage. At the same time, the outer or inlet portion of the inlet/exhaust valve moves off its seat, permitting supply air to flow from the reservoir, past the open inlet valve and into the brake chambers.
BALANCE
The air pressure being delivered by the open inlet valve also is effective on the bottom area of the relay piston.
When air pressure beneath the piston equals the service air pressure above, the piston lifts slightly and the inlet spring returns the inlet valve to its seat. The exhaust remains closed as the service line pressure balances the
2 delivery pressure. As delivered air pressure is changed, the valve reacts instantly to the change, holding the brake application at that level.
EXHAUST OR RELEASE
When air pressure is released from the service port and air pressure in the cavity above the relay piston is exhausted, air pressure beneath the piston lifts the relay piston and the exhaust seat moves away from the exhaust valve, opening the exhaust passage. With the exhaust passage open, the air pressure in the brake chambers is then permitted to exhaust through the exhaust port, releasing the brakes.
ANTI COMPOUNDING (SIMULTANEOUS
SERVICE AND PARK APPLICATION)
In those applications where the R-14 Relay Valve is used to control spring brake chambers, the anti-compound feature may be utilized. With the anti-compound feature of the R-14 connected, a service application made while the vehicle is parked is countered by a release of the parking brakes. To utilize this feature, the exhaust cover of the quick release portion of the R-14 is removed and a line is installed which is connected to the delivery of the service brake valve or relay valve. With no air pressure at the service port of the R-14, the parking brakes are applied.
If a service brake application is made, air from the service brake valve enters the exhaust port of the quick release of the R-14 and moves the diaphragm, blocking the service port. Air then proceeds into the cavity above the relay piston, forces the piston down, closing the exhaust and
opening the inlet to deliver air to the spring brake cavity as described under the section of this manual entitled
Application .
PREVENTIVE MAINTENANCE
Important: Review the warranty policy before performing any intrusive maintenance procedures. An extended warranty may be voided if intrusive maintenance is performed during this period.
Because no two vehicles operate under identical conditions, maintenance and maintenance intervals will vary.
Experience is a valuable guide in determining the best maintenance interval for any one particular operation.
1. Every three months or 25,000 miles or 900 operating hours check for proper operation.
2. Every twelve months or 100,000 miles or 3600 operating hours: disassemble valve, clean parts with mineral spirits. Replace all rubber parts and any part worn or damaged. Check for proper operation before placing vehicle in service.
OPERATIONAL AND LEAKAGE TEST
1. Chock the wheels, fully charge air brake system and adjust the brakes.
2. Make several brake applications and check for prompt application and release at each wheel.
3. Check for inlet valve and o-ring leakage.
A. Make this check with the service brakes released when the R-12 or R-14 is used to control the service brakes.
B. Make the check with the spring brakes applied
(PARK) when the R-14 is used to control the spring brakes. Coat the exhaust port and the area around the retaining ring with a soap solution; a 1 inch bubble in 3 seconds leakage is permitted.
4. Check for exhaust valve leakage.
A. Make this check with the service brakes fully applied if the R-12 or R-14 control the service brakes.
B. Make this check with the spring brakes fully released if the R-14 is used to control the spring brakes. Coat the exhaust port with a soap solution; a 1 inch bubble in 3 seconds leakage is permitted.
Coat the outside of the valve where the cover joins the body to check for seal ring leakage; no leakage is permitted.
5. If the R-14 is used to control the spring brakes, place the park control in the released position and coat the balance port with a soap solution to check the diaphragm and its seat. Leakage equivalent to a 1 inch bubble in 3 seconds is permitted.
Note: If the anti-compound feature is in use, the line attached to the balance port must be disconnected to perform this test.
If the valves do not function as described above, or if leakage is excessive, it is recommended that the valves be replaced with new or remanufactured units or repaired with genuine Bendix parts, available at any authorized Bendix parts outlet.
REMOVAL AND INSTALLATION
REMOVAL
1. Block and hold vehicle by means other than air brakes.
2. Drain air brake system reservoirs.
3. If entire valve is to be removed, identify air lines to facilitate installation.
4. Disconnect air lines from valve*.
5. Remove valve from reservoir or if remotely mounted, remove mounting bolts and then valve.
*It is generally not necessary to remove entire valve to service the inlet/exhaust valve. The inlet/exhaust valve insert can be removed by removing the snap ring, exhaust cover assembly and then inlet/exhaust valve.
Caution: Drain all reservoirs before attempting to remove the inlet exhaust valve.
DISASSEMBLY
Note: Prior to disassembly, mark the location of the mounting bracket to the cover and the cover to the body.
1. Remove the four (4) cap screws and lockwashers securing the cover to the body.
2. Remove the cover, sealing ring, and mounting bracket.
3. Remove the piston and o-ring from the body.
4. While depressing the exhaust cover, remove the retaining ring and slowly relax the spring beneath the exhaust cover.
5. Remove the exhaust cover assembly and o-rings.
6. Remove the inlet/exhaust valve return spring from the body.
7. Remove the inlet/exhaust valve from the body.
8. Remove the valve retainer from the inlet/exhaust valve.
9. Remove the Phillips head screw and exhaust cover from the R-14 cover.
10. Remove the service port cap nut and o-ring from the
R-14.
11. Remove the diaphragm from the R-14 cover.
3
4
TRAILER RELEASE
TRAILER PARK
SYSTEM PARK
TP-3 TRACTOR PROTECTION
SR-1 SPRING BRAKE VALVE
CHECK & STOP LIGHT
SPRING BRAKES
SERVICE RESERVOIR
R-12 RELAY VALVE
SPRING BRAKES
FRONT SERVICE
E-7, E-12
DOUBLE CHECK VALVE
TRAILER CONTROL VALVE
R-14 RELAY VALVE
BP-R1 BOBTAIL
SERVICE RESERVOIR
REAR AXLE SERVICE RESERVOIR
QUICK RELEASE VALVE
CLEANING AND INSPECTION
1. Wash all metal parts in mineral spirits and dry them thoroughly.
( Note: When rebuilding, all springs and all rubber parts should be replaced.)
2. Inspect all metal parts for deterioration and wear, as evidenced by scratches, scoring and corrosion.
3. Inspect the exhaust valve seat on the relay piston for nicks and scratches which could cause excessive leakage.
4. Inspect the inlet valve seat in the body for scratches and nicks, which could cause excessive leakage.
5. Inspect the exhaust seat of the quick release diaphragm in the R-14 cover and make sure all internal air passages in this area are open and clean and free of nicks and scratches.
6. Replace all parts not considered serviceable during these inspections and all springs and rubber parts. Use only genuine Bendix replacement parts, available from any authorized Bendix parts outlet.
ASSEMBLY
Note: All torque specified in this manual are assembly torque and can be expected to fall off slightly after assembly. Do not re-torque after initial assembly torque fall.
For assembly, hand wrenches are recommended.
Prior to assembly, lubricate all o-rings, o-ring bores and any sliding surface with a silicone lubricant equivalent to
Dow Corning #10.
1. Install large piston o-ring on piston.
2. Install inner and outer o-rings in the exhaust cover assembly.
3. Install the sealing ring on the cover.
4. Install piston in body, taking care not to damage the piston o-ring.
5. Noting the reference marks made during disassembly, install the cover on the valve body and the mounting bracket on the cover.
6. Secure the mounting bracket and cover to the body using the four (4) cap screws and lock washers. Torque to 80-120 inch pounds.
7. Install the valve retainer on the inlet/exhaust valve and install in the body.
8. Install the inlet/exhaust valve return spring in the body.
9. Install the exhaust cover assembly in the body, taking care not to damage the o-ring.
10. While depressing the exhaust cover, install the retaining ring. Make certain the retainer is completely seated in its groove in the body.
11. Install the R-14 service port cap nut o-ring on the cap nut. Install the diaphragm in the R-14 cover making certain it is positioned between the guide ribs in the cover.
13. Install the service port cap nut and torque to 150 inch pounds.
14. If the quick release exhaust port was protected with an exhaust cover, install the cover using the #10-24
Phillips head screw. Torque to approx. 15-25 inch pounds.
15. Test the valves as outlined in the Operational and Leakage Test section before returning the valve to service.
INSTALLATION
1. Clean air lines.
2. Inspect all lines and/or hoses for damage and replace as necessary.
3. Install valve and tighten mounting bolts.
4. Connect air lines to valve (plug any unused ports).
5. Test valve as outlined in Operational and Leakage
Tests .
IMPORTANT! PLEASE READ
When working on or around a vehicle, the following general precautions should be observed:
1. Park the vehicle on a level surface, apply the parking brakes, and always block the wheels.
2. Stop the engine when working around the vehicle.
3. If the vehicle is equipped with air brakes, make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle.
4. Following the vehicle manufacturers recommended procedures, deactivate the electrical system in a manner that removes all electrical power from the vehicle.
5. When working in the engine compartment the engine should be shut off. Where circumstances require that the engine be in operation, EXTREME
CAUTION should be used to prevent personal injury resulting from contact with moving, rotating, leaking, heated, or electrically charged components.
6. Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a component or plug unless you are certain all system pressure has been depleted.
7. Never exceed recommended pressures and always wear safety glasses.
5
8. Do not attempt to install, remove, disassemble or assemble a component until you have read and thoroughly understand the recommended procedures. Use only the proper tools and observe all precautions pertaining to use of those tools.
9. Use only genuine Bendix replacement parts, components, and kits. Replacement hardware, tubing, hose, fittings, etc. should be of equivalent size, type, and strength as original equipment and be designed specifically for such applications and systems.
10. Components with stripped threads or damaged parts should be replaced rather than repaired. Repairs requiring machining or welding should not be at tempted unless specifically approved and stated by the vehicle or component manufacturer.
11. Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition.
6
8 BW1431 © AlliedSignal Truck Brake Systems Co. 1/1999. Printed in U.S.A.
R-12DC RELAY VALVE WITH BIASED DOUBLE CHECK
PRIMARY
SERVICE SECONDARY
SERVICE
EXTERIOR R-12DC
(MODEL WITH
4 VERTICAL DELIVERY
PORTS)
SUPPLY (2)
DELIVERY
EXTERIOR R-12DC (MODEL WITH 2 HORIZONTAL PORTS)
EXTERIOR R-12DC
(MODEL WITH 2
HORIZONTAL AND 2
VERTICAL DELIVERY
PORTS)
FIGURE 1 - EXTERIOR VIEWS.
DESCRIPTION
The Relay Valve in an air brake system functions as a relay station to speed up the application and release of the brakes. The valve is normally mounted at the rear of the vehicle in proximity to the chambers it serves. The valve operates as a remote controlled brake valve that delivers or releases air to the chambers in response to the control air delivered to it from the foot brake valve.
The R-12DC Relay Valves are designed for either reservoir or frame mounting. (See Figure 1). For ease of servicing, the inlet/exhaust valve can be replaced without the need for line removal.
CAP SCREW
SEALING
RING
RELAY
PISTON
O-RING
EXHAUST
SEAT
SPRING
O-RINGS
PRIMARY
SERVICE
PORT
COVER
RETAINING
RING
FIGURE 2 - R-12DC SECTIONAL VIEW
SECONDARY
SERVICE PORT
EXHAUST
PORT
RELAY
PISTON
VALVE
RETAINER
INLET
EXHAUST
VALVE
SPRING
GUIDE
DOUBLE CHECK
DIAPHRAGM
1
OPERATION
APPLICATION
Under normal conditions, the internal biased double check valve assures that the primary service signal controls the valve. Air pressure delivered to the primary service port enters the small cavity above the piston and moves the piston down. The exhaust seat moves down with the piston and seats on the inner or exhaust portion of the inlet/exhaust valve, sealing off the exhaust passage. At the same time, the outer or inlet portion of the inlet/exhaust valve moves off its seat, permitting supply air to flow from the reservoir, past the open inlet valve and into the service brake chambers. In the event of a loss of the primary service line, (see Figure 4) the double check valve mechanism in the cover of the R-12DC will move, shutting off the primary service line, and instead allow the secondary service line to apply the air pressure needed to operate the valve.
Note: Secondary service line may leak out of the primary service at control pressures up to 20 psi when the primary signal is not present.
BALANCE
The air pressure being delivered by the open inlet valve also is effective on the bottom area of the relay piston.
R-12DC
RELAY PISTON
INLET
EXHAUST
VALVE
RESERVOIR
EXHAUST
PORT
BRAKE VALVE
(DELIVERY
LINES ARE
SHOWN)
ANTILOCK
MODULATOR
ANTILOCK SENSOR
TONE RING
BRAKE
CHAMBERS
FIGURE 3 - R-12DC SECTIONAL VIEW WITH TYPICAL
SYSTEM COMPONENTS
BRAKE PEDAL
APPLIED
BRAKE PEDAL
APPLIED
NORMAL: BIASED
DOUBLE-CHECK VALVE
ALLOWS PRIMARY
CONTROL LINE SUPPLIES
RELAY PISTON
CONTROL LINE
FAILURE
BRAKE PEDAL
APPLIED
BRAKES
APPLIED
SECONDARY
CONTROL LINE
SUPPLIES RELAY
PISTON
FIGURE 4 - R-12DC APPLIED POSITION (SHOWING BIASED DOUBLE CHECK OPERATIONAL VIEWS)
2
BRAKE PEDAL
POSITION
HELD
BRAKE
PEDAL
RELEASED
AIR PRESSURE
ABOVE RELAY
VALVE IS
EXHAUSTED
HERE
BRAKE
CHAMBERS
MAINTAIN
APPLICATION
FIGURE 5 - R-12DC BALANCE POSITION
When air pressure beneath the piston equals the service air pressure above, the piston lifts slightly and the inlet spring returns the inlet valve to its seat. The exhaust remains closed as the service line pressure balances the delivery pressure. As delivered air pressure is changed, the valve reacts instantly to the change, holding the brake application at that level.
EXHAUST OR RELEASE
When air pressure is released from the service port and air pressure in the cavity above the relay piston is exhausted through the brake valve. At the same time, air pressure beneath the piston lifts the relay piston and the exhaust seat moves away from the exhaust valve, opening the exhaust passage. With the exhaust passage open, the air pressure in the brake chambers is then permitted to exhaust through the exhaust port, releasing the brakes.
PREVENTIVE MAINTENANCE
Important: Review the warranty policy before performing any intrusive maintenance procedures. An extended warranty may be voided if intrusive maintenance is performed during this period.
Because no two vehicles operate under identical conditions, maintenance and maintenance intervals will vary.
AIR PRESSURE
FROM BRAKE
CHAMBERS IS
EXHAUSTED
HERE
FIGURE 6 - R-12DC EXHAUST POSITION
BRAKE
CHAMBERS
RELEASED
Experience is a valuable guide in determining the best maintenance interval for any one particular operation.
1. Every three months or 25,000 miles or 900 operating hours check for proper operation.
2. Every twelve months or 100,000 miles or 3600 operating hours: disassemble valve, clean parts with mineral spirits. Replace all rubber parts and any worn or damaged part. Check for proper operation before placing vehicle in service.
REMOVAL AND INSTALLATION
REMOVAL
1. Block and hold vehicle by means other than air brakes.
2. Drain air brake system reservoirs.
3. If entire valve is to be removed, identify air lines to facilitate installation. Prior to disassembly, remove as much contamination as possible from the exterior of the device taking care to keep all contamination from entering the open ports.
4. Disconnect air lines from valve*.
5. Remove valve from reservoir or if remotely mounted, remove mounting bolts and then valve.
3
12
13
14
15
8
9
10
11
16
17
18
6
7
4
5
2
3
Key No.
1
DESCRIPTION
VALVE COVER
VALVE SPRING
CHECK VALVE GUIDE
CHECK VALVE
O-RING
DOUBLE CHECK COVER
O-RING
O-RING
RELAY PISTON
VALVE BODY
INLET & EXHAUST VALVE
VALVE RETAINER
SPRING
O-RING
O-RING
EXHAUST COVER
RETAINING RING
DIFFERENTIAL SPRING (IF USED)
1
CAP SCREW
2
PRIMARY CONTROL
PORT 1/4 NPT
4
3
5
6
7
8
SECONDARY
CONTROL PORT
1/4 NPT
CAP
SCREW
9
18
DIFFERENTIAL SPRING
(CONTROLS CRACK PRESSURE*)
(NOT REQUIRED FOR MOST
MODELS.
SEE BELOW.)
HORIZONTAL
DELIVERY
PORTS
DIFFERENTIAL SPRINGS
*Crack Pressure is the amount of control pressure required by the valve to initiate air delivery. For Crack pressures other than 4 psi, a differential spring is used in the assembly to produce the required valve response.
(Models designed to have a 4 psi crack pressure do not require a differential spring.)
VERTICAL
DELIVERY
PORTS
11
12
13
15
14
16
17
10
SUPPLY
PORT
FIGURE 7 - R-12DC EXPLODED VIEW
*It is generally not necessary to remove entire valve to service the inlet/exhaust valve. The inlet/exhaust valve insert can be removed by removing the snap ring, exhaust cover assembly and then inlet/exhaust valve.
Caution: Drain all reservoirs before attempting to remove the inlet exhaust valve.
DISASSEMBLY
Note: Prior to disassembly, mark the location of the mounting bracket to the cover and the cover to the body.
CAUTION: The valve body may be lightly clamped in a bench vise during disassembly, however, over-clamping will result in damage to the valve and result in leakage and/or malfunction. If a vise is to be used, position the valve so that the jaws bear on the supply ports on opposing sides of the valves body.
1. Remove the four cap screws securing the mounting bracket and cover to the body. Retain the cap screws for reuse.
2. Discard the mounting bracket.
3. Remove and discard sealing ring (7) from the cover
(1).
4
a.
Remove the 2 torx screws securing the double check cover (6) to the cover (1).
b.
Remove the double check cover (6) from cover (1) and remove and discard spring (2), guide
(3), double check diaphragm (4), and o-ring (5).
4. Remove and discard sealing ring (7) from the cover
(1), and mounting bracket.
5. Remove piston (9) from the body (10) and retain for reuse.
6. Remove and discard o-ring (8) from piston (9).
7. Depress and hold the exhaust cover assembly (16) and remove and discard retaining ring (17) from the valve body (10).
8. Slowly release the holding force on the exhaust cover assembly (16) to relax the spring.
9. Remove and discard the following parts: a.
b.
c.
d.
e.
Exhaust cover assembly (16)
O-rings (14 & 15)
Spring (13)
Inlet exhaust valve (11)
Retainer (12)
CLEANING AND INSPECTION
1. Wash all metal parts in mineral spirits and dry them thoroughly.
( Note: When servicing the R-12DC, all springs and all rubber parts should be replaced.)
2. Inspect all metal parts for deterioration and wear, as evidenced by scratches, scoring and corrosion.
3. Inspect the exhaust valve seat on the relay piston for nicks and scratches which could cause excessive leakage.
4. Inspect the inlet valve seat in the body for scratches and nicks, which could cause excessive leakage.
5. Inspect the check valve seat in the R-12DC cover and make sure all internal air passages in this area are open and clean and free of nicks and scratches.
6. Replace all parts not considered serviceable during these inspections and all springs and rubber parts. Use only genuine Bendix replacement parts, available from any authorized Bendix parts outlet.
ASSEMBLY
Note: All torque specified in this manual are assembly torque and can be expected to fall off slightly after assembly.
Do not re-torque after initial assembly torque fall. For assembly, hand wrenches are recommended.
Prior to assembly, lubricate all o-rings, o-ring bores and any sliding surface with a silicone lubricant equivalent to
Dow Corning #10.
Wash all remaining parts in mineral spirits and dry thoroughly. Using the lubricant provided in this kit, lightly lubricate all o-rings, o-ring grooves, body bores any sliding surfaces.
1. Install o-rings (14 & 15) in the exhaust cover assembly
(16).
2. Install o-ring (8) on piston (9).
3. Install sealing ring (7) on cover (1)
4. Install retainer (12) on inlet exhaust valve (11) and insert both in the body (10).
5. Install spring (13) in the body (10).
6. Install exhaust cover assembly (16) in the body (10).
Depress and hold the exhaust cover assembly in the body.
7. Install retaining ring (17) in the body (10). Make certain the retaining ring is completely seated in the groove in the body.
8. Install piston (9) in body (10).
9. Install o-ring (5) on double check cover (6), install spring
(2), guide (3) and double check diaphragm (4) in cover
(1). Install cover (1) and torque torx head screws to
80-100 in. lbs.
10. Referring to the marks made during disassembly, install cover (1)
11. Install the mounting bracket (not shown) on the cover
(1).
12. Install the four cap screws in the cover (1) and torque to 80-100 inch pounds
13. Test the valve as outlined in the Operational and
Leakage Test section before returning the valve to service.
INSTALLATION
1. Clean air lines.
2. Inspect all lines and/or hoses for damage and replace as necessary.
3. Install valve and tighten mounting bolts.
4. Connect air lines to valve (plug any unused ports).
5. Test valve as outlined in Operational and Leakage Tests .
OPERATIONAL AND LEAKAGE TEST
1. Chock the wheels, fully charge air brake system and adjust the brakes.
2. Make several brake applications and check for prompt application and release at each wheel.
5
6
SPRING BRAKES
SPRING BRAKE RELAY VALVE
R-12DC RELAY VALVE
SPRING BRAKES
DIAGNOSTIC CONNECTION
PARKING VALVE
WARNING INDICATORS
ABS ECU
SR-1 SPRING BRAKE VALVE SERVICE BRAKE VALVE
QUICK RELEASE VALVE
DOUBLE CHECK VALVE
REAR AXLE SERVICE RESERVOIR
SERVICE RESERVOIR
SINGLE CHECK VALVE
WARNING INDICATOR
3. Check for inlet valve and o-ring leakage. Make this check with the service brakes released. Coat the exhaust port and the area around the retaining ring with a soap solution; a 1 inch bubble in 3 seconds leakage is permitted.
4. Check for exhaust valve leakage. Make this check with the service brakes fully applied. Coat the outside of the valve where the cover joins the body to check for seal ring leakage; no leakage is permitted.
If the valves do not function as described above, or if leakage is excessive, it is recommended that the valves be replaced with new or remanufactured units or repaired with genuine Bendix parts, available at any authorized
Bendix parts outlet.
IMPORTANT! PLEASE READ
When working on or around a vehicle, the following general precautions should be observed:
1. Park the vehicle on a level surface, apply the parking brakes, and always block the wheels.
2. Stop the engine when working around the vehicle.
3. If the vehicle is equipped with air brakes, make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle.
4. Following the vehicle manufacturers recommended procedures, deactivate the electrical system in a manner that removes all electrical power from the vehicle.
5. When working in the engine compartment the engine should be shut off. Where circumstances require that
the engine be in operation, EXTREME CAUTION should be used to prevent personal injury resulting from contact with moving, rotating, leaking, heated, or electrically charged components.
6. Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a component or plug unless you are certain all system pressure has been depleted.
7. Never exceed recommended pressures and always wear safety glasses.
8. Do not attempt to install, remove, disassemble or assemble a component until you have read and thoroughly understand the recommended procedures.
Use only the proper tools and observe all precautions pertaining to use of those tools.
9. Use only genuine Bendix replacement parts, components, and kits. Replacement hardware, tubing, hose, fittings, etc. should be of equivalent size, type, and strength as original equipment and be designed specifically for such applications and systems.
10. Components with stripped threads or damaged parts should be replaced rather than repaired. Repairs requiring machining or welding should not be at tempted unless specifically approved and stated by the vehicle or component manufacturer.
11. Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition.
7
8 BW1933 © AlliedSignal Truck Brake Systems Co. 1/1999. Printed in U.S.A.
m a i n m e n u local s e a r c h global s e a r c h
o p e r a t i o n t r o u b l e s h o o t i n g
PRESSURE PROTECTION VALVES
DESCRIPTION
The pressure protection valve is a normally closed, pressure control valve which can be referred to as a non-exhausting sequence valve. These valves are used in many different applications. An example would be in an air brake system to protect one reservoir, or reservoir system from another, by closing automatically at a preset pressure should a reservoir system failure occur. The valves can also be used
*Formerly SD-03-55 to delay filling of auxiliary reservoirs to insure a quick build-up of brake system pressure.
The PR-2 and PR-4 pressure protection valves have one 1/
4" N.P.T.F. supply port and one 1/4" N.P.T.F. delivery port which are identified. Both valves are provided with two 9/
32" mounting holes through the body. The closing pressure of the PR-2 is externaIly adjustable while the PR-4 has a fixed setting.
SPRING
CAP
INLET
VALVE
PISTON
CHECK
VALVE
INLET
PORT
SPRING
PR-3 OR PR-4
CAP
PISTON
VALVE
DELIVERY
PORT
PR-4
PRESSURE
REGULATING
SPRING
EXHAUST
VENT
PISTON
O-RING
PISTON
SPRING
RETAINER
INLET
VALVE
PR-3
PISTON PLUG
PISTON PLUG
O-RING
VALVE STEM
INLET
VALVE SPRING
PR-2
1
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OPERATION
Air entering the supply port is initially prevented from flowing out the delivery port by the inlet valve which is held closed by the pressure regulating spring above the piston. When sufficient air pressure builds beneath the piston to overcome the setting of the regulating spring, the piston will move, causing the inlet valve to unseat (open), and allow air to flow out the delivery port. As long as air pressure at the supply port and beneath the piston remains above the specified closing pressure, the inlet valve will remain open.
NOTE: The PR-2 and PR-4 closing pressure is noted on the label affixed to the valve. Opening pressures of the valves are higher than closing pressures. The pressure ranges are noted below:
PR-2-Opening pressure 15-20 psi higher than closing pressure.
PR-3 & PR-4-Opening pressure approx. 10 psi higher than closing pressure.
PR-3-Check valve will retain maximum pressure in downstream reservoir.
If for any reason system air pressure is decreased below the specified closing pressure, the regulating spring will move the piston closing the inlet valve. The remaining air pressure at either the supply or delivery side, (depending upon where the pressure drop has occurred) will be retained.
PREVENTIVE MAINTENANCE
local s e a r c h
Every three months, 900 operating hours or 25,000 miles, whichever if first, it is recommended that the operation and leakage checks described in this manual be performed.
global s e a r c h
o p e r a t i o n t r o u b l e s h o o t i n g
4. (PR-3 only) Build pressure up again and shut off engine.
Slowly exhaust air from the supply side of the PR-3.
The gauge on the delivery side of the valve should remain at the highest pressure previously attained.
LEAKAGE CHECKS
1 . Build up the air system to full pressure and shut off the engine.
2. Apply a soap solution around the cap of the pressure protection valve. A one-inch bubble in three seconds or longer is acceptable. PR-3 - No leakage permissable at bottom of valve.
3. Drain the air pressure from the delivery side of the pressure protection valve and disconnect the air line to it.
4. Apply a soap solution to the delivery port. A one inch bubble in five seconds or more is acceptable.
GENERAL
If the pressure protection valve does not operate as described or leakage is excessive, it is recommended that a replacement be obtained at the nearest authorized
AlliedSignal Truck Brake Systems Co. distributor.
REMOVING AND INSTALLING
REMOVING
1 . Block or hold the vehicle by means other than air brakes.
2. Drain all system reservoirs individually, to 0 psi.
3. Disconnect and identify (supply and delivery) the air lines leading to and from the pressure protection valve.
4. Remove the mounting bolts, if any, that secure the valve.
OPERATING AND LEAKAGE CHECKS
OPERATING CHECKS
1. Provide a pressure gauge and drain valve at the supply side and delivery side of the pressure protection valve being checked.
2. Build up the air system to full pressure and shut off the engine.
3. While watching the gauges on the supply and delivery sides of the valve, slowly begin to exhaust pressure from the delivery side. Note that both gauges will show pressure loss until the closing pressure of the pressure protection valve is reached.
The pressure protection valve should close at approximately ( ± 5 psi) the pressure indicated on the valve’s label or in the vehicle handbook. The gauge on the delivery side of the valve should continue to show loss of pressure while the gauge on the supply side should stop at the same pressure as the setting of the valve.
INSTALLING
1. Re-install the mounting bolts and secure the replacement valve to the vehicle.
2. Reconnect the supply delivery air lines to the proper ports of the replacement valve.
GENERAL
After installing a replacement valve, it is recommended that the operating and leakage checks be performed as outlined in this manual. If the closing pressure does not conform to that shown on the valve label or in the vehicle or a different setting is desired, the PR-2 may be adjusted by loosening the locknut and tightening or loosening the adjusting cap as required; however, if the proper setting cannot be attained by moderate adjustment of the cap, the valve may have the wrong spring and will have to be exchanged for the correct valve. The PR-3 and PR-4 are not adjustable.
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IMPORTANT! PLEASE READ
When working on or around a vehicle, the following general precautions should be observed:
1. Park the vehicle on a level surface, apply the parking brakes, and always block the wheels.
2. Stop the engine when working around the vehicle.
3. If the vehicle is equipped with air brakes, make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle.
4. Following the vehicle manufacturer’s recommended procedures, deactivate the electrical system in a manner that removes all electrical power from the vehicle.
5. When working in the engine compartment the engine should be shut off. Where circumstances require that the engine be in operation, EXTREME
CAUTION should be used to prevent personal injury resulting from contact with moving, rotating, leaking, heated, or electrically charged components.
6. Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a global s e a r c h
o p e r a t i o n t r o u b l e s h o o t i n g
component or plug unless you are certain all system pressure has been depleted.
7. Never exceed recommended pressures and always wear safety glasses.
8. Do not attempt to install, remove, disassemble or assemble a component until you have read and thoroughly understand the recommended procedures. Use only the proper tools and observe all precautions pertaining to use of those tools.
9. Use only genuine Bendix replacement parts, components, and kits. Replacement hardware, tubing, hose, fittings, etc. should be of equivalent size, type, and strength as original equipment and be designed specifically for such applications and systems.
10. Components with stripped threads or damaged parts should be replaced rather than repaired.
Repairs requiring machining or welding should not be attempted unless specifically approved and stated by the vehicle or component manufacturer.
11. Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition.
BW1440 © AlliedSignal Truck Brake Systems Co. 1/1999. Printed in U.S.A.
3
DOUBLE CHECK VALVES
DELIVERY
SUPPLY
DELIVERY
*FORMERLY SD-03-67
SUPPLY
SUPPLY
DELIVERY
SUPPLY
SHUTTLE
VALVE
O-RING
CAP
DELIVERY
VALVE
DISC
O-RING
CAP
SHUTTLE
GUIDE
BODY
FIGURE 1 - DOUBLE CHECK VALVE (SHUTTLE TYPE)
DESCRIPTION
Double Check Valves are used in an air brake system to direct a flow of air into a common line from either of two sources, whichever is at the higher pressure. They may be used for directing air flow for specific functions or to select the higher pressure of either of two sources of air as a supply source.
AlliedSignal manufactures two types of Bendix Double Check
Valves: shuttle and disc. Although the valves are somewhat different physically, the same function is performed by both types. The difference in the design of the two valves is that the shuttle type has a movable shuttle to seal off the lower pressure source, whereas the disc type has a movable disc.
OPERATION
As air under pressure enters either end of the Double Check
Valve (inlet port) the moving shuttle or disc responds to the pressure and seals the opposite port, assuming it is at a lower pressure level than the other. The air flow continues out the delivery port of the Double Check Valve. The position
VALVE
GUIDE
BODY
FIGURE 2 - DOUBLE CHECK VALVE (DISC TYPE) of the shuttle or disc will reverse if the pressure levels are reversed. Double Check Valves are designed so that the shuttle or disc can never impede the backflow of air in the exhaust mode.
Figure 3 (see page 2) illustrates a typical use of a Double
Check Valve to control a given device, such as trailer brakes, from either of two control sources.
Figure 4 (see page 2) illustrates a typical use of a Double
Check Valve to supply air to a system or systems from either of two separate sources, whichever is at the greater pressure level. In this type of installation the pressure differential to which the valve is subjected may under certain conditions be minimal. It is therefore suggested that performance of the Double Check Valve will be optimized if it is mounted in the horizontal position.
PREVENTIVE MAINTENANCE
Every 3600 operating hours, 100,000 miles, or yearly, disassemble, clean and inspect all parts. Install new parts if they show signs of wear or deterioration.
1
PP-1
Reservoir
Reservoir
Trailer Hand
Control Valve
PP-7
Brake Valve
Trailer Supply
To Trailer
Brakes
Double
Check
Valve
FIGURE 3 - DOUBLE CHECK VALVE: CONTROL OF
SYSTEM FROM EITHER OF TWO CONTROL SOURCES
Spring Brake Control
Reservoir
Double Check
Valve
FIGURE 4 - DOUBLE CHECK VALVE: SYSTEM WITH TWO
SUPPLY SOURCES
SERVICE CHECKS
OPERATING AND LEAKAGE TEST
A. When the Double Check Valve is used in conjunction with a Trailer Control Valve, the following operating and leakage test can be made:
1. Apply and release foot brake valve and note that the brakes apply and release on both tractor and trailer.
2
2. Apply and release the Trailer Control Valve and note that only the trailer brakes apply and release. With trailer control valve applied check exhaust port of foot brake valve for leakage with soap solution.
Permissible leakage is a one inch bubble in five seconds (100 sccm).
3. Apply and hold a full foot brake valve application.
Check exhaust port of Trailer Control Valve for leakage with soap solution. Permissible leakage is a one inch bubble in five seconds (100 sccm). ( Note : On some vehicles, an exhaust line is connected to the exhaust port and piped outside the cab in which case it may be necessary to disconnect this line to make leakage check.)
B. If Double Check Valve is to be bench tested or tested on the vehicle, two separately controlled air supplies must be connected to the inlet ports.
1. Install an accurate test gauge in the outlet port or in a line from outlet port.
2. Apply and release air to one inlet port and note that gauge registers application and release.
3. Repeat by applying and releasing air to other inlet port.
4. Leakage check should be performed at inlet ports of valve in the following manner: a.
Disconnect line from one inlet port.
b.
Apply air to other inlet port and coat opposite inlet port with soap solution. Permissible leakage is a one inch bubble in five seconds (100 sccm).
c.
Repeat Step b applying air to other inlet port while checking opposite inlet port for leakage.
If the Double Check Valve does not function as described or if leakage is excessive, it is recommended that the valve be repaired or replaced with genuine Bendix parts. The following instructions should prove helpful:
DISASSEMBLY
1. Remove end cap(s) from valve.
2. Remove grommets (if applicable).
3. Remove shuttle and/or shuttle guide, disc and/or disc guide (depending upon type of valve).
CLEANING AND INSPECTION
1. Clean all metal parts in a cleaning solvent.
2. Inspect all metal parts for signs of cracks, wear or deterioration. Replace all parts not considered serviceable.
3. Replace all rubber parts.
ASSEMBLY
1. Install disc guide, disc and/or shuttle and shuttle guide.
2. Coat all static seals such as o-rings, grommets, etc.
with BW 650M Silicone lubricant (BW 291126). It is not necessary to lubricate shuttles or discs.
3. Install grommets.
4. Install end cap(s).
TESTING OF REBUILT DOUBLE CHECK VALVE
Perform operating and leakage tests as described in Service Checks section.
IMPORTANT! PLEASE READ:
When working on or around a vehicle, the following general precautions should be observed:
1. Park the vehicle on a level surface, apply the parking brakes, and always block the wheels.
2. Stop the engine when working around the vehicle.
3. If the vehicle is equipped with air brakes, make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle.
4. Following the vehicle manufacturers recommended procedures, deactivate the electrical system in a manner that removes all electrical power from the vehicle.
5. When working in the engine compartment the engine should be shut off. Where circumstances require that the engine be in operation, EXTREME
CAUTION should be used to prevent personal injury resulting from contact with moving, rotating, leaking, heated, or electrically charged components.
6. Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a component or plug unless you are certain all system pressure has been depleted.
7. Never exceed recommended pressures and always wear safety glasses.
8. Do not attempt to install, remove, disassemble or assemble a component until you have read and thoroughly understand the recommended procedures. Use only the proper tools and observe all precautions pertaining to use of those tools.
9. Use only genuine Bendix replacement parts, components, and kits. Replacement hardware, tubing, hose, fittings, etc. should be of equivalent size, type, and strength as original equipment and be designed specifically for such applications and systems.
10. Components with stripped threads or damaged parts should be replaced rather than repaired. Repairs requiring machining or welding should not be attempted unless specifically approved and stated by the vehicle or component manufacturer.
11. Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition.
3
4
BW1846 © AlliedSignal Truck Brake Systems Co. 1/1999. Printed in U.S.A.
m a i n m e n u local s e a r c h global s e a r c h
o p e r a t i o n t r o u b l e s h o o t i n g
TW-1, TW-3, TW-4, TW-5 & TW-6 CONTROL VALVES
*Formerly SD-03-64
SCREW
10-24
THD.
(2 HOLES)
REVERSED
LEVER
POSITION
LEVER
DIAL
3
5
4 1.38”
PANEL
THICKNESS**
**SEE NOTE
2 BELOW
1/8” P.T.
DELIVERY
(2 PORTS) 2.5”
6
7
8
9
FIGURE 1 - TW-1
1/8” P.T.
SUPPLY
EXHAUST
2
SPRING
RETAINING
RING
3
4
5
37.5° 37.5°
LEVER
235034
PIN
PLUNGER
1/4” NPT
VALVE
SPRING
BODY
1/4” NPT
FIGURE 2 - TW-3
DESCRIPTION
The TW series valves are manually operated on-off valves.
They are extensively used in air systems to control nonmodulating air controlled devices. They may be lever or button operated, direct or remote control.
The TW-1 (Figure 1) is normally panel mounted with a steel, zinc or nylon manually operated lever. Some are equipped with a steel lever with connectors for Bowden cable control.
All TW-1’s have 1/8" NPT ports.
1.38”
1/8” NPT
LEVER
237144
B
1/8” P.T.
SUPPLY
.28” DIA.
2 HOLES-1.88”
APART
A
1/4” NPT
SUPPLY
The TW-3 (Figure 2) is lever operated, either direct or remote and differs from the TW-1 in having 1/4" NPT ports and larger capacity. Some versions have a heavy inlet valve spring making them suitable for vacuum control.
TW-4’s and TW-5’s (Figure 3) are similar to the TW-1 except the plunger is designed for a push button, giving momentary application whenever the button is depressed.
The TW-6 (Figure 4) is a TW-1 with a grounding switch included. In the exhaust position the switch is open. When the valve is applied the switch is closed.
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SCREW local s e a r c h
PUSH
BUTTON
NUT global s e a r c h
o p e r a t i o n t r o u b l e s h o o t i n g
FIGURE 3 - TW-4 FIGURE 4 - TW-6
OPERATION
With air pressure a the supply port (Figure 1) and the plunger in the upward position the valve is in the exhaust position. The delivery ports are open to atmosphere through the exhaust passage in the center of the plunger.
When the plunger is depressed by the cam action of the lever (Figure 1) or by a direct force on a push button (Figure
3) the plunger contacts the inlet valve, closing the exhaust passage and pushes the inlet valve off the inlet seat in the body, allowing supply air to flow through the delivery ports to the controlled device.
PREVENTIVE MAINTENANCE
Every year, 100,000 miles or 1800 operating hours disassemble, clean and check all parts and replace if necessary.
SERVICE CHECKS
OPERATING AND LEAKAGE TESTS
Connect a 100 psi air pressure source to the supply port and connect delivery to an air gauge. (if there are two delivery ports, plug one.) With the valve in the released position, check for leakage at the exhaust holes with a soap solution. No leakage permitted. Place the valve in the applied position. Supply air pressure should show on the gauge.
Check for leakage at the exhaust holes. No leakage permitted.
If the TW valve does not function as described or if leakage occurs, it is recommended that it be replaced with a new unit or repaired with genuine Bendix parts.
REMOVING
Secure the vehicle with other means than brakes and drain the reservoirs.
Disconnect all air lines and remove the valve.
INSTALLING
Place valve handle through appropriate hole in panel, place dial (if used) over handle and install mtg. screws. Connect air lines.
DISASSEMBLY
Remove operating handle or lever by driving the pin out of the body (Figure 1) and remove the lever, plunger and plunger spring. Remove the O-Ring from the plunger.
Remove the supply cap nut, inlet valve and spring. Remove the 0-Ring from the supply cap nut.
CLEANING AND INSPECTION OF PARTS
Wipe rubber parts clean. Clean plastic and metal parts in mineral spirits and dry thoroughly. Inspect all rubber parts for wear or deterioration and replace where necessary. Polish the inlet seat in the body if nicked or corroded. Inspect all springs for cracks, distortion or corrosion and replace if necessary.
ASSEMBLY
Prior to assembly lubricate body bore, plunger, O-Rings, and cap nut threads with Bendix silicone lubricant BW 650M
Pc. No. 291126.
Place inlet valve in body.
Place inlet valve spring on inlet valve.
Place O-Ring on cap nut and install cap nut.
Install plunger spring from top of body.
Install O-Ring on plunger and install plunger.
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TW-1 TW-3 & TW-6 local s e a r c h global s e a r c h
Depress plunger, place lever cam in slot in body, line up holes in body with hole in lever and insert pin.
TW-4 & TW-5
Depress plunger with button until hole in plunger lines up with holes in body. Insert pin.
LEAKAGE TEST
Test valve per instructions in paragraph on “Service Checks.”
IMPORTANT! PLEASE READ
When working on or around a vehicle, the following general precautions should be observed:
1. Park the vehicle on a level surface, apply the parking brakes, and always block the wheels.
2. Stop the engine when working around the vehicle.
3. If the vehicle is equipped with air brakes, make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle.
4. Following the vehicle manufacturer’s recommended procedures, deactivate the electrical system in a manner that removes all electrical power from the vehicle.
5. When working in the engine compartment the engine should be shut off. Where circumstances require that the engine be in operation, EXTREME CAUTION should be used to prevent personal injury resulting from contact
o p e r a t i o n t r o u b l e s h o o t i n g
with moving, rotating, leaking, heated, or electrically charged components.
6. Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a component or plug unless you are certain all system pressure has been depleted.
7. Never exceed recommended pressures and always wear safety glasses.
8. Do not attempt to install, remove, disassemble or assemble a component until you have read and thoroughly understand the recommended procedures.
Use only the proper tools and observe all precautions pertaining to use of those tools.
9. Use only genuine Bendix replacement parts, components, and kits. Replacement hardware, tubing, hose, fittings, etc. should be of equivalent size, type, and strength as original equipment and be designed specifically for such applications and systems.
10. Components with stripped threads or damaged parts should be replaced rather than repaired. Repairs requiring machining or welding should not be attempted unless specifically approved and stated by the vehicle or component manufacturer.
11. Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition.
BW1580 © AlliedSignal Truck Brake Systems Co. 1/1999. Printed in USA.
3
operation
PUSH-PULL TYPE CONTROL VALVES: PP-1, PP-2, PP-5, PP-8, & RD-3
*FORMERLY SD-03-61
PP-1 PP-5
RD-3
PP-8
PP-2
FIGURE 1 - PUSH-PULL TYPE CONTROL VALVES
DESCRIPTION
The PP valves are push-pull manually operable on-off air control valves with an exhaust function. Most are pressure sensitive, so that they will automatically move from the applied to the exhaust position as supply pressure is reduced to a certain minimum, depending on the spring installed.
The exception to this is the PP-8 valve and some PP-1 valves which have no spring. The PP-8 valve also has a larger diameter shaft for button mounting so that when installed on the same panel with other PP valves the buttons cannot be inadvertently mixed. The PP-8 is normally used to operate tractor spring brakes independently from the trailer.
The PP-5 is unique in having an auxiliary piston in the lower cover which, upon receiving a pneumatic signal of 18 psi or more, will cause the valve to move from the applied to the exhaust position from a 100 psi application.
The RD-3 differs slightly in that it normally remains in the exhaust position and requires a constant manual force to hold it in the applied position.
The PP-2 has an auxiliary port which may be plumbed into a service brake line to release the spring brakes if a service application is made, preventing compounding of forces on the foundation brakes.
PREVENTIVE MAINTENANCE
Every six months, 50,000 miles or 1800 operating hours, disassemble, clean and replace parts if necessary.
REMOVAL
Block and/or hold the vehicle by a means other than air brakes and drain all reservoirs.
1. Drive the Button Roll-Pin out with a punch and remove the button.
2. Mark each air supply line and its port for easy reinstallation, then disconnect them. Remove the valve from the panel by removing the Panel Mounting Nut.
1
PP-1
PP-2
PP-5
RD-3
PP-8
AUTOMATIC MOMENTARY
EXHUAST APPLY
20,30,40 or 60 psi
40 psi
40 psi
Must be held manually
PILOT TRIP
FEATURE
NON-
AUTOMATIC
18 psi
Will remain in either position
INSTALLING
1. Install valve in panel, securing with the Panel Mounting
Nut.
2. Reconnect the air lines using marks made during removal as a guide.
3. Install the operating button. Secure the operating button by installing the Button Roll Pin.
DISASSEMBLY: PP-1, PP-8 AND RD-3
1. Remove the two cap screws (3) which retain the lower cover and remove cover. Remove the sealing ring (4).
2. Insert a small punch through the roll pin hole in the stem and remove the lock nut (5).
3. Remove inlet-exhaust valve (6) and plunger (7) and spring
(8) (if any).
4. Remove o-ring (9) from plunger.
DISASSEMBLY: PP-5
1. Perform same operations as for PP-1.
2. Remove inlet seal (10) in Figure 4 from lower cover.
Remove the ring diaphragm (4) from the inlet seat.
3. Remove piston (11) Figure 4 and o-ring (2).
DISASSEMBLY: PP-2
1. Insert a small punch through the roll pin hole in the plunger and remove the lock nut (1) from the plunger.
2. Withdraw the plunger and remove the spring (9) and oring (8).
3. Remove the two machine screws (2) and remove the lower cover (3).
4. Remove the inlet-exhaust valve (4), and piston (5).
5. Remove o-rings (6 & 7) from piston.
OPERATING AND LEAKAGE TESTS
PP-1, PP-8, RD-3
1. An accurate test gauge should be teed into the supply line and a means of controlling the supply pressure provided. Apply a 120 psi air source to the supply port. A small volume reservoir (e.g. 90 cu. in.) with a gauge should be connected to the delivery port.
2 operation
2. With 120 psi supply pressure, and the button pulled out
(exhaust position), leakage at the exhaust port should not exceed a 1" bubble in five seconds; at the plunger stem a 1" bubble in five seconds. There should be no leakage between upper and lower body.
3. Push the button in (applied position). Leakage at the exhaust port should not exceed a 1" bubble in 3 seconds; at the plunger a 1" bubble in three seconds. (The
RD-3 will have to be manually held in this position.)
4. Reduce the supply pressure. At a pressure from 60 to
20 psi depending on the spring installed the button should pop out automatically, exhausting the delivery volume.
(This does not apply to the RD-3, PP-8 or some PP-
1s).
PP-5
1. Proceed as for PP-1 through Step 3.
2. Connect a modulated source of air pressure to the pilot air inlet. With the button pushed in (applied position) with 125 psi supply pressure and a gradually increasing pressure applied at the pilot air port the valve should move to the release position with a pilot pressure of not more than 18 psi. Leakage in this mode should not exceed a 1" bubble in three seconds at the exhaust port and a 1" bubble in five seconds at the plunger stem.
PP-2
1. Proceed as for PP-1 through Step 1.
2. With the button pulled out (exhaust position), leakage at the brake valve port or at the plunger stem should not exceed a 1" bubble in five seconds.
3. Push the button in. Supply pressure should be present in the delivery volume. Leakage at the exhaust port or around the plunger stem should not exceed a 1" bubble in five seconds.
4. Pull the button out and apply supply pressure at the brake valve port. Supply pressure should be present in the delivery volume and leakage at the exhaust port should not exceed a 1" bubble in five seconds.
Note: If any of the above push-pull valves do not function as described or if leakage is excessive, it is recommended they be returned to our nearest authorized distributor for a factory rebuilt or new valve.
IMPORTANT! PLEASE READ:
When working on or around a vehicle, the following general precautions should be observed:
1. Park the vehicle on a level surface, apply the parking brakes, and always block the wheels.
2. Stop the engine when working around the vehicle.
PANEL
MOUNTING
NUT
8
6
5
FIGURE 2
PP-1
BUTTON ROLL
PIN
9
7
3
4
PANEL
MOUNTING
NUT
9 operation
BUTTON ROLL
PIN
8
4
BRAKE
VALVE
PORT
FIGURE 3
5
1
PP-2
6
3
2
7
PANEL
MOUNTING
NUT
9
7
9
8
7
6
10
5
4 6 4
3
11
3
PP-5
2
FIGURE 4
3. If the vehicle is equipped with air brakes, make certain to drain the air pressure from all reservoirs before beginning any work on the vehicle.
4. Following the vehicle manufacturers recommended procedures, deactivate the electrical system in a manner that removes all electrical power from the vehicle.
5
FIGURE 5
PP-8
5. When working in the engine compartment the engine should be shut off. Where circumstances require that the engine be in operation, extreme caution should be used to prevent personal injury resulting from contact with moving, rotating, leaking, heated, or electrically charged components.
3
6. Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a component or plug unless you are certain all system pressure has been depleted.
7. Never exceed recommended pressures and always wear safety glasses.
8. Do not attempt to install, remove, disassemble or assemble a component until you have read and thoroughly understand the recommended procedures. Use only the proper tools and observe all precautions pertaining to use of those tools.
9. Use only genuine Bendix replacement parts, components, and kits. Replacement hardware, tubing, hose, fittings, etc. should be of equivalent size, type, and strength as original equipment and be designed specifically for such applications and systems.
10. Components with stripped threads or damaged parts should be replaced rather than repaired. Repairs requiring machining or welding should not be attempted unless specifically approved and stated by the vehicle or component manufacturer.
11. Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition.
PANEL
MOUNTING
NUT
6
FIGURE 6
5 operation
RD-3
BUTTON ROLL
PIN
9
7
8
3
4
4
BW1578 © AlliedSignal Truck Brake Systems Co. 1/1999. Printed in USA.
m a i n m e n u local s e a r c h global s e a r c h
SR-1 SPRING BRAKE VALVE
*Formerly SD-03-87
1/4 P.T.
RES. #1
1/4 P.T.
CONTROL
1/4 P.T.
SUPPLY
1/4 P.T.
DELIVERY
PISTON SPRING
(14)
PISTON (15)
PISTON O-RINGS
(16)
VALVE (12)
VALVE SPRING (11)
VALVE STOP (10)
O-RING (9)
CAP NUT
(8)
COVER (13)
INLET &
EXHAUST
VALVE (7)
PISTON
SPRINGS (14)
O-RING
(LARGE)
(18)
PISTON (17)
O-RING
(SMALL) (19)
BODY
CHECK
VALVE (4)
CHECK
VALVE SPRING (2)
DIAPHRAGM
(6)
PIPE PLUG
(1)
EXHAUST
COVER (5)
FIGURE 1 - EXTERIOR VIEW
DESCRIPTION:
The SR-1 Spring Brake Valve is used in dual or “split” air brake systems equipped with spring brake actuators. The function of the SR-1 is to supply a specific, limited hold-off pressure to the spring brakes, and in the event of loss of
No. 1 service air pressure, to modulate the spring brakes through the use of the service brake valve.
The valve has four identified 1/4" N.P.T.F. ports and a diaphragm protected exhaust port. Two 5/16" diameter holes are provided in the integral mounting bracket of the valve body. The SR-1 must be mounted with the exhaust port down toward the road surface.
FIGURE 2 - SECTIONAL VIEW
Air flowing from the No. 1 reservoir only enters the reservoir port of the SR-1. This air remains under piston A as system pressure builds. With No. 1 reservoir pressure below approximately 55 P.S.I. the spring above piston A forces it into contact with inlet and exhaust valve A causing the exhaust to seal and the inlet to open.
With air system pressure above approximately 55 P.S.I. in
No. 1 & 2 service reservoirs, piston A has moved against the force of the spring above it, allowing the inlet of valve A to close and opening the hollow exhaust passage through piston A.
OPERATION - INITIAL AIR SYSTEM CHARGE
Upon initial charge, air from #1 & #2 service reservoirs flows through the park control valve and enters the SR-1 supply port. Air entering the supply port flows past inlet and exhaust valve B to the underside of piston B and out the delivery port of the SR-1 to the emergency air connection at the spring brake actuator. Note that the springs above piston B force it into contact with inlet and exhaust valve B.
In the position shown the exhaust is closed and the inlet is open.
OPERATION - AIR BRAKE SYSTEM FULLY
CHARGED
When air pressure beneath piston B is approximately 95**
P.S.I., piston B rises slightly, against the force of the springs above it, allowing the inlet of valve B to close. The exhaust through valve B remains closed. The closing of the inlet portion of valve B retains approximately 95* P.S.I. in the hold- off cavity of the spring brake actuators while allowing full air system pressure to build elsewhere.
**Note: Other spring brake hold-off pressures are supplied according to the vehicle manufacturer ’s specifications. 95 P.S.I. was chosen only for the purpose of explanation.
1
m a i n m e n u
MODULATOR local s e a r c h global s e a r c h
PP-7
CONTROL
VALVE DS-1
TP-3 TRACTOR PROTECTION
SB-3
PARK
CONTROL
LQ-4
DOUBLE
CHECK
VALVE
LP-3
#2 SERVICE
RESERVOIR
R-8
SUPPLY
RESERVOIR
#1 SERVICE
RESERVOIR
SB-3
R-8
SB-3
SB-3
FIGURE 3 - PIPING DIAGRAM
#2 SERVICE
RESERVOIR
#1 SERVICE
RESERVOIR
PISTON A
DOUBLE
CHECK
VALVE
PARK CONTROL
FIGURE 4 - CHARGING - BELOW 55 P.S.I.
2
INLET &
EXHAUST A
INLET &
EXHAUST
B
EXHAUST
SB-3
PISTON B
CHECK VALVE
m a i n m e n u local s e a r c h
#2 SERVICE
RESERVOIR
#1 SERVICE
RESERVOIR global s e a r c h
PISTON A
PISTON B
CHECK VALVE
INLET &
EXHAUST A
DOUBLE
CHECK
VALVE
PARK CONTROL
FIGURE 5 - SYSTEM FULLY CHARGED
#2 SERVICE
RESERVOIR
#1 SERVICE
RESERVOIR
PISTON A
INLET &
EXHAUST A
INLET &
EXHAUST
B
EXHAUST
SB-3
PISTON B
CHECK VALVE
DOUBLE
CHECK
VALVE
PARK CONTROL
INLET &
EXHAUST
B
EXHAUST
SB-3
FIGURE 6 - NORMAL SERVICE APPLICATION
OPERATION - NORMAL SERVICE
RESERVOIRS 1& 2 CHARGED
When a service application is made by actuating the dual brake valve; air, from the No. 2 delivery circuit is delivered from the brake valve to the control port, and is stopped at the closed inlet of valve A. No movement of the internal components of the SR-1 takes place. Air from the No. 1 delivery circuit of the dual brake valve actuates the service section of the spring brake actuators.
OPERATION - SERVICE APPLICATION WITH
LOSS OF NO. 2 RESERVOIR PRESSURE
In the event air pressure is lost in No. 2 reservoir, the No. 1 reservoir as well as the parking control valve will be protected through the action of the double and single check valves in the air system. A service application of the dual air brake valve in this situation results in little or no air being delivered from the No. 2 delivery circuit to the control port of the
SR-1. No movement of the SR-1 internal components takes place. Braking is assured because the No. 1 service reservoir is protected by a check valve and the No. 1 delivery
3
m a i n m e n u local s e a r c h
#2 SERVICE
RESERVOIR
#1 SERVICE
RESERVOIR global s e a r c h
PISTON A
PISTON B
CHECK VALVE
INLET &
EXHAUST A
PARK CONTROL
DOUBLE
CHECK
VALVE
FIGURE 7 - SERVICE APPLICATION - LOSS OF #2 RESERVOIR
#2 SERVICE
RESERVOIR
PISTON A
SB-3
INLET &
EXHAUST
B
EXHAUST
PISTON B
#1 SERVICE
RESERVOIR
CHECK VALVE
INLET &
EXHAUST A
INLET &
EXHAUST
B
EXHAUST
DOUBLE
CHECK
VALVE
PARK CONTROL
SB-3
FIGURE 8 - SERVICE APPLICATION - LOSS OF #1 RESERVOIR circuit of the dual brake valve will apply the service section of the spring brake actuators.
OPERATION - SERVICE APPLICATION WITH
LOSS OF NO. 1 RESERVOIR PRESSURE
If air pressure in the No. 1 service reservoir falls below approximately 55 P.S.I., the pressure beneath piston A is insufficient to resist the spring force above and piston A moves into contact with valve A. Initial contact between piston
A and valve A closes the hollow exhaust passage of piston
A. Continued movement of the piston opens the inlet of valve A.
The No. 2 service reservoir and the park control valve are protected from pressure loss by the action of the Double
Check Valve.
When a service application of the dual brake valve is made, air delivered from the No. 2 delivery circuit of the dual brake valve enters the SR-1 control port. Air entering the control port, now moves past the inlet of valve A and is conducted through a passage in the body to the underside of piston B. The added force of air pressure beneath piston
B, moves up, opening the exhaust of valve B. When the exhaust of valve B opens, air pressure trapped in the emergency section of the spring brake actuator is allowed to escape resulting in a brake application by the emergency section. The amount of air pressure released from the spring brake is in proportion to the amount of air pressure delivered to the control port of the SR-1 by the No. 2 delivery of the dual brake valve.
4
m a i n m e n u local s e a r c h
#2 SERVICE
RESERVOIR
#1 SERVICE
RESERVOIR global s e a r c h
PISTON A
PISTON B
CHECK VALVE
INLET &
EXHAUST A
INLET &
EXHAUST
B
EXHAUST
PARK CONTROL
DOUBLE
CHECK
VALVE
FIGURE 9 - PARK APPLICATION
OPERATION - PARKING
If both systems #1 and #2 are intact and the park control valve is placed in the “park” or exhaust position, the SR-1 supply of air pressure and the air pressure in the spring brake actuator cavities is exhausted. The single check valve in the SR-1 assists this exhaust of air pressure from the spring brake by allowing the air below piston B to flow back out the open exhaust of the park control valve. When air pressure below piston B has dropped sufficiently, piston B moves down opening the inlet of valve B thus providing an additional exhaust passage for air exhausting through the
SR-1 from the spring brakes.
PREVENTIVE MAINTENANCE
Every 3600 operating hours, 100,000 miles or yearly, disassemble valve, clean all parts in mineral spirits. Replace all rubber parts, and any part worn or damaged with genuine
Bendix parts.
SERVICE CHECKS
OPERATING CHECKS
Block vehicle and hold by means other than vehicle brakes.
Charge air brake system to governor cut-out pressure.
1. Place parking control valve in the “park” position.
Observe that the spring brake actuators apply promptly.
In the delivery port of the valve install a test gauge known to be accurate. Place the parking control valve in the
“release” position. Observe that the spring brake actuators release fully.
2. With the parking control valve in the “release” position, note the gauge pressure reading. (Check the vehicle manual for the correct spring brake actuator hold-off pressure.) If the pressure reading is incorrect, the valve must be repaired or replaced.
SB-3
3. Place the parking control valve in the “park” position, the gauge reading should drop to zero promptly. A slow release of pressure may indicate faulty operation of the single check valve (within the Modulating Valve.)
4. Place the parking control valve in the “release” position.
Locate the number one service reservoir and drain it completely.
Apply the foot brake valve several times and note that the pressure reading on the gauge decreases each time the foot brake valve is applied. After several applications, pressure on the gauge will drop to the point where release of the spring brake actuators will no longer occur.
LEAKAGE CHECK
With the air system fully charged and the parking control valve in the “release” position, coat the exhaust port and around the valve corner with a soap solution. Slight leakage is permitted.
If the SR-1 Spring Brake Valve does not function as described above, or leakage is excessive, it is recommended that it be returned to the nearest Bendix authorized distributor for a new or remanufactured valve. If this is not possible, the valve can be repaired with genuine Bendix parts in which case the following should prove helpful.
Note: A maintenance kit for the SR-1 Spring Brake Valve is available from any authorized Bendix outlet. All parts necessary for minor repair are included.
REMOVAL
1. Prior to removing the SR-1 apply the parking brakes and drain all the vehicle reservoirs.
2. Identify all air lines before disconnecting.
3. Remove the two mounting bolts from the SR-1 and remove the valve.
5
m a i n m e n u local s e a r c h
DISASSEMBLY (REFER TO FIGURE 2)
1. Remove the socket head pipe plug (1).
2. Remove the check valve spring (2) and the check valve
(4).
3. Remove the two phillips head screws and remove the exhaust cover (5).
4. Separate the exhaust diaphragm (6) from the cover.
5. Remove the inlet and exhaust valve assembly (7).
6. Remove the inlet and exhaust valve cap nut (8) and separate the cap nut o-ring (9).
7. Remove the valve stop (10) valve spring (11) and inlet and exhaust valve (12).
8. Remove the four phillips head screws and lockwashers that secure the cover to the body. Caution: the cover is under a spring load, and should be held while removing the screws.
9. Remove the cover (13) and the three piston springs
(14). Note: Some SR-1 piece numbers have one large piston spring.
10. Remove the small piston (15) and the small and large o-rings (16).
11. Remove the large piston (17). Remove piston o-rings
(18) & (19).
CLEANING & INSPECTION
Wash all metal parts in mineral spirts and dry.
Inspect all parts for excessive wear or deterioration.
Inspect the valve seats for nicks or burrs.
Check the springs for cracks or corrosion.
Replace all rubber parts and any part not found to be serviceable during inspection. Use only genuine Bendix replacement parts.
ASSEMBLY (REFER TO FIGURE 2)
Prior to assembly of the SR-1 Spring Brake Valve, lubricate all o-rings, o-ring grooves, and piston bores with Dow
Corning 55-M Pneumatic Grease (Bendix No. 291126).
Note: All torques specified in this manual are assembly torques and can be expected to fall off, after assembly is accomplished. Do not retorque after initial assembly torques fall.
1 . Assemble the check valve (4), and valve spring (2) and install in body.
2. Apply pipe sealant to the socket head pipe plug (1) and install in the body. Tighten to 130-170 inch pounds torque.
3. Install inlet and exhaust valve assembly (7) in valve body.
global s e a r c h
4. Secure the exhaust cover (5) with two 10-24 phillips screws and lockwashers. Tighten to 20-30 inch pounds torque.
5. Install exhaust diaphragm (6) into the exhaust cover.
6. Place inlet exhaust valve (12) in the body. Install the valve spring (11 ) and valve stop (10).
7. Install o-ring (9) on cap nut and install cap nut (8) in body. Tighten to 100- 125 inch pounds torque.
8. Install the small and large o-rings (16) on the small diameter piston (15) and install piston in the body.
9. Install large o-ring (18) and small o-ring (19) on the large diameter piston and install piston in the body.
10. Install the piston springs (14) in their respective pistons.
11. Secure the cover to body using four 1/4"-20 phillips head screws and lockwashers. Tighten to 50-80 inch pounds torque.
TESTING THE REBUILT SR-1 SPRING BRAKE
VALVE
Test the rebuilt SR-1 Spring Brake Valve by performing the operation and leakage test outlined in the “Service Checks” section of this manual.
IMPORTANT! PLEASE READ
When working on or around a vehicle, the following general precautions should be observed:
1. Park the vehicle on a level surface, apply the parking brakes, and always block the wheels.
2. Stop the engine when working around the vehicle.
3. If the vehicle is equipped with air brakes, make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle.
4. Following the vehicle manufacturer’s recommended procedures, deactivate the electrical system in a manner that removes all electrical power from the vehicle.
5. When working in the engine compartment the engine should be shut off. Where circumstances require that the engine be in operation, EXTREME CAUTION should be used to prevent personal injury resulting from contact with moving, rotating, leaking, heated, or electrically charged components.
6. Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a component or plug unless you are certain all system pressure has been depleted.
7. Never exceed recommended pressures and always wear safety glasses.
8. Do not attempt to install, remove, disassemble or assemble a component until you have read and thoroughly understand the recommended procedures.
6
m a i n m e n u local s e a r c h global s e a r c h
Use only the proper tools and observe all precautions pertaining to use of those tools.
9. Use only genuine Bendix replacement parts, components, and kits. Replacement hardware, tubing, hose, fittings, etc. should be of equivalent size, type, and strength as original equipment and be designed specifically for such applications and systems.
10. Components with stripped threads or damaged parts should be replaced rather than repaired. Repairs requiring machining or welding should not be attempted unless specifically approved and stated by the vehicle or component manufacturer.
11. Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition.
7
m a i n m e n u local s e a r c h global s e a r c h
8
BW1589 © AlliedSignal Truck Brake Systems Co. 1/1999. Printed in USA.
LOW PRESSURE INDICATORS
*Formerly SD-06-2
COVER
DIAPHRAGM
BODY
SPRING
CONTACT
POINTS
COVER
SPRING
CONTACT
POINTS
PISTON
BODY
O-RING
DIAPHRAGM
FIGURE 1 - LP-2
DESCRIPTION
The Low Pressure Indicator is a safety device designed to give an automatic warning to the driver whenever air pressure in the air brake system is below the safe minimum for normal vehicle operation. It is usually used to operate an electrical buzzer or warning light, or both, which are audible or visible to the driver.
Two styles of Low Pressure Indicators are currently manufactured.
The LP-2 Low Pressure Indicator, which is the older style and consists of a die cast body with a spring loaded diaphragm clamped between the body and the Bakelite cover.
The LP-3 Low Pressure Indicator is the newer style, consisting of a die cast body, nylon cover and employs a spring loaded O-Ring diaphragm and piston. The LP-3 is
FIGURE 2 - LP-3 available with either one terminal or two. The single terminal unit utilizes a metallic gasket between body and case to ground the lower contract strip. The two terminal unit utilizes a phenolic insulating gasket to isolate both terminals from the vehicle frame.
The electrical contacts provided in both the LP-2 and LP-3 indicators remain closed by spring force until the air brake system pressure below the diaphragm is above the setting
(force) of the Low Pressure Indicator spring. The setting of the indicator and piece number is marked on a label on the valve body. If a label is not present, then the vehicle manual should be consulted for the proper setting. The nominal setting of the indicator is 60 psi; however, pressure settings may vary depending upon the vehicle.
OPERATION
To describe the operation, we shall assume that the Low
1
Pressure Indicator is set for 60 psi. When air pressure at the supply port and under the diaphragm is above 60 psi, the electrical contacts remain open because the force exerted by air pressure underneath the diaphragm overcomes the force exerted by the spring above the diaphragm.
When air pressure below the diaphragm drops below 60 psi, the spring exerts a force which is greater than the force exerted by the air pressure below the diaphragm.
This causes the diaphragm (and the piston in the LP-3) to move and allow the electrical contacts to close. This completes or closes the electrical circuit to the warning device, warning the driver of low air pressure in the system.
PREVENTIVE MAINTENANCE
Every six months, 1800 operating hours or 50,000 miles, check electrical connections. Low Pressure Indicator should be checked for proper operation by performing Operating
Test as described elsewhere in this sheet.
TESTING FOR SERVICEABILITY
OPERATING TEST
1. If possible, determine the setting of the Low Pressure
Indicator by referring to the label on the valve or the vehicle manual.
2. Operation of the Low Pressure Indicator may be checked with ignition switch on by reducing the system pressure and observing that low pressure warning occurs when system pressure drops below the setting of the Low Pressure Indicator. The contacts will be closed when the warning device operates. If the setting of the indicator is unknown, the contacts should close between approximately 70 psi and 50 psi.
LEAKAGE TEST
1. With air pressure present at the supply port, coat the indicator with soap solution. No leakage permitted.
REMOVING
1. Block the wheels. Otherwise, secure the vehicle with other than service brakes.
2. The ignition switch should be in the off position.
3. Drain the air from the system.
4. Disconnect the electrical connections at the Low
Pressure Indicator.
5. Disconnect the air line and mounting bolts or unscrew the Indicator from the fitting and remove.
INSTALLING
1. Install in a convenient location for servicing.
2. Connect to a reservoir pressure line at a high point in the system for adequate drainage.
2
3. If installing an LP-2G Indicator, use a supply line of 1/4
O.D. minimum.
4. Connect the Indicator terminals in series with the ignition switch and the warning device.
DISASSEMBLY
NOTE: It is generally recommended that the Low Pressure
Indicator, if faulty, be replaced with a new unit; however, service parts are available; and if repairs are necessary, the following will apply:
LP-2 Unscrew the cover retainer from the body. Remove cover and remove spring and diaphragm assembly.
LP-3. Remove cover screws, lockwashers. Remove cover, contact disc, spring, and shim(s). (Note: Shims may or may not be present.) Remove contact plate, gasket, piston, and O-Ring diaphragm.
CLEANING AND INSPECTION
Clean all metal parts in mineral spirits.
Inspect all parts for wear, cracks, or deterioration and replace all parts not considered serviceable with genuine
Bendix parts.
If contact points are not pitted severely, they can be dressed with a fine file.
ASSEMBLY
LP-2
1. Place and position the diaphragm assembly in the body.
Position the spring so that it rests on the upper diaphragm follower.
2. Place cover over the diaphragm and screw cover retainer to the body and tighten securely. (Torque to 110-130 inch pounds.)
LP-3
1. Lubricate bore of body and both sides of the O-Ring diaphragm with silicone lubricant BW-650-M (Bendix piece no. 291126).
2. Install O-Ring diaphragm in body. (Note: O-Ring portion of diaphragm should face supply port.)
3. Install piston in body. Flat side of piston should face
O-Ring diaphragm.
4. Install gasket. (Always use a phenolic gasket in a two terminal switch and a metallic gasket in the single terminal.)
5. Position contact plate over fingers of piston. Contact plate should rest on face of gasket.
6. If shim(s) are used, place shim(s) in cover.
7. Place spring in cover.
8. Place contact point so that it rests on spring.
9. Install cover on body, using machine screws, making certain that the contact plate is in position over fingers of piston, and arm of contact plate is positioned so that it will fit in groove of cover.
10. Tighten screws securely. (Torque to 20-30 inch pounds).
TEST OF REBUILT LOW PRESSURE INDICATOR
After rebuilding, perform the leakage and operating tests as outlined in section Testing for Serviceability.
IMPORTANT! PLEASE READ
When working on or around a vehicle, the following general precautions should be observed:
1. Park the vehicle on a level surface, apply the parking brakes, and always block the wheels.
2. Stop the engine when working around the vehicle.
3. If the vehicle is equipped with air brakes, make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle.
4. Following the vehicle manufacturers recommended procedures, deactivate the electrical system in a manner that removes all electrical power from the vehicle.
5. When working in the engine compartment the engine should be shut off. Where circumstances require that the engine be in operation, EXTREME CAUTION should be used to prevent personal injury resulting from contact
with moving, rotating, leaking, heated, or electrically charged components.
6. Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a component or plug unless you are certain all system pressure has been depleted.
7. Never exceed recommended pressures and always wear safety glasses.
8. Do not attempt to install, remove, disassemble or assemble a component until you have read and thoroughly understand the recommended procedures.
Use only the proper tools and observe all precautions pertaining to use of those tools.
9. Use only genuine Bendix replacement parts, components, and kits. Replacement hardware, tubing, hose, fittings, etc. should be of equivalent size, type, and strength as original equipment and be designed specifically for such applications and systems.
10. Components with stripped threads or damaged parts should be replaced rather than repaired. Repairs requiring machining or welding should not be attempted unless specifically approved and stated by the vehicle or component manufacturer.
11. Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition.
BW1447 © AlliedSignal Truck Brake Systems Co. 1/1999. Printed in USA.
3
SL-5 STOP LIGHT SWITCH & DS-2 COMBINED
STOP LIGHT SWITCH & DOUBLE CHECK VALVE
*Formerly SD-06-7
DS-2
FULCRUM
CONTACT
STRIP
LEAF
SPRING
SHORTING
BAR
INLET PORT
TERMINAL
RIVET
PISTON
DIAPHRAGM
SHUTTLE
VALVE
(CHECK
VALVE
SL-5
INLET
PORT
FIGURE 1 - DS-2 SECTIONAL
DESCRIPTION
The stop light switch (SL-5) is an electro-pneumatic 5 psi non- grounded switch that operates in conjunction with the brake valve and stop lights by completing the electrical circuit and lighting the stop lights when a brake application is made.
The combined stop light switch and double check valve
(DS-2), as the name implies, combines a stop light switch
(SL-5) with a double check valve to perform the function of both. It operates in conjunction with the brake valve and hand control valve by directing the flow of air from whichever delivers the higher pressure into a common delivery line and to the stop light switch, closing the electrical circuit to the stop lamps.
The stop light switch can be used with either 12 or 24 volt systems.
OUTLET PORT
The stoplight switch is not a serviceable item; and if found defective in either device, the complete unit must be replaced.
The shuttle valve in the DS-2 is serviceable and may be replaced.
Both the SL-5 and DS-2 have been tested and meet the requirements of FMVSS-121.
OPERATION
The stop switch mechanism is identical in the SL-5 and
DS-2.
When a brake application is made, air pressure from the brake valve enters the cavity below the diaphragm. The air pressure below the diaphragm moves the piston until it contacts the leaf spring. The leaf spring travels past a
1
fulcrum at which point the leaf springs snaps a shorting bar which mates with the contact strips. The stop light electrical circuit is completed, lighting the stop lights before the brake application pressures reach 6 psi.
The snap action spring design minimizes arcing.
The Double Check Valve is activated by air being introduced through either of the two (2) inlet ports. The greater pressure pushes the shuttle along its guides and closes the opposite inlet port. The air is then directed out the common delivery line and to the stop light switch.
PREVENTIVE MAINTENANCE
Every six months, 1800 operating hours or 50,000 miles check the electrical connections and determine that stop lamps operate properly.
OPERATING AND LEAKAGE TEST
1. Install an accurate air gauge in the service line (or brake chamber). Apply brake valve gradually. Stop lamps should light at 6 psi or less and go out after the brake application is released. This checks the electrical function of the stop light switch in either the SL-5 or
DS-2.
2. (DS-2 only) Apply the foot valve and coat the exhaust port of the hand valve (or other alternate source). Reverse the above, applying the hand valve or other alternate source and coat the exhaust port of the foot valve. In either mode a leakage of not more than a 1 bubble in 5 seconds is permissible.
3. (SL-5 or DS-2) When pressurized, no leakage is permitted from the body of the valve or switch.
If the SL-5 or DS-2 does not function as described above or if leakage is excessive, the valve or switch should be replaced with a new unit or in the case of the double check portion of the DS-2 repaired with genuine Bendix parts.
REMOVING AND INSTALLING
REMOVING
1. Block vehicle wheels or hold by means other than vehicle service brakes.
2. Disconnect electrical connections from terminal screws.
3. (SL-5) Remove the switch using a wrench on the hex portion of the body.
4. (DS-2) Disconnect air lines and remove the DS-2.
INSTALLING
1. Replace the SL-5 or DS-2 in the port from which it was removed. Do not install with the terminals pointing down.
2. Secure electrical connections.
3. Reinstall air line connections to DS-2 valve.
2
DISASSEMBLY (Double Check Valve)
1. Remove three cap screws and cap.
2. Remove O-Ring seal from cap.
3. Remove shuttle valve.
CLEANING AND INSPECTION
1. Blow dust or other foreign material out of body. Do not immerse in cleaning fluid.
2. Inspect shuttle valve and O-Ring and replace if deteriorated.
TEST
Repeat Operating and Leakage Test.
IMPORTANT! PLEASE READ
When working on or around a vehicle, the following general precautions should be observed:
1. Park the vehicle on a level surface, apply the parking brakes, and always block the wheels.
2. Stop the engine when working around the vehicle.
3. If the vehicle is equipped with air brakes, make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle.
4. Following the vehicle manufacturers recommended procedures, deactivate the electrical system in a manner that removes all electrical power from the vehicle.
5. When working in the engine compartment the engine should be shut off. Where circumstances require that the engine be in operation, EXTREME CAUTION should be used to prevent personal injury resulting from contact with moving, rotating, leaking, heated, or electrically charged components.
6. Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a component or plug unless you are certain all system pressure has been depleted.
7. Never exceed recommended pressures and always wear safety glasses.
8. Do not attempt to install, remove, disassemble or assemble a component until you have read and thoroughly understand the recommended procedures.
Use only the proper tools and observe all precautions pertaining to use of those tools.
9. Use only genuine Bendix replacement parts, components, and kits. Replacement hardware, tubing, hose, fittings, etc. should be of equivalent size, type, and strength as original equipment and be designed specifically for such applications and systems.
10. Components with stripped threads or damaged parts should be replaced rather than repaired. Repairs requiring machining or welding should not be attempted unless specifically approved and stated by the vehicle or component manufacturer.
11. Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition.
BW1594 © AlliedSignal Truck Brake Systems Co. 1/1999. Printed in USA.
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AD-9 AIR DRYER
UPPER
BRACKET
UPPER
BRACKET
OUTER
SHELL
LOWER
BRACKET
END COVER
CHECK
VALVE
ASSEMBLY
PORT
CONTROL
SUPPLY
PORT
WIRING HARNESS
CONNECTION DELIVERY PORT
EXTENDED PURGE AD-9 AIR DRYER
END COVER
CHECK
VALVE
ASSEMBLY
DELIVERY PORT
WIRING HARNESS
CONNECTION
STANDARD AD-9 AIR DRYER
OUTER
SHELL
LOWER
BRACKET
CONTROL
PORT
SUPPLY
PORT
FIGURE 1 - AD-9 AIR DRYER MODELS
DESCRIPTION
The function of the AD-9 A ir D ryer is to collect and remove air system contaminants in solid, liquid and vapor form before they enter the brake system. It provides clean, dry air to the components of the brake system which increases the life of the system and reduces maintenance costs. Daily manual draining of the reservoirs is eliminated.
The AD-9 Air Dryer consists of a desiccant cartridge and a die cast aluminum end cover secured to a cylindrical steel outer shell with eight cap screws and nuts. The end cover contains a check valve assembly, a safety valve, three threaded air connections and the purge valve housing assembly. The removable purge valve housing assembly incorporates a purge valve mechanism and a turbo charger cut-off feature that is designed to prevent loss of engine
turbo boost pressure during the purge cycle of the AD-9 air dryer. For ease of serviceability, the desiccant cartridge and discharge check valve assembly are screw in type.
The purge valve housing assembly, which includes the heater and thermostat assembly, and the discharge check valve assembly, is serviceable from the exterior of the air dryer, while servicing the screw-in desiccant cartridge requires removal of the air dryer assembly from the vehicle.
The AD-9 has three female pipe thread air connections and each is identified as follows:
Port l.D.
Function/Connection
CON 4 .............. Control Port
(purge valve control and turbo cut-off).
SUP 11 ............. Supply Port (air in).
DEL 2 ............... Delivery Port (air out).
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DESSICANT
CARTRIDGE
¬
CHECK
VALVE
¬
¬
¬
¬
ORIFICE
¬
DESSICANT
BED
PURGE
VOLUME
OIL
SEPARATOR
CONTROL
PORT
¬
¬
GOVERNOR COMPRESSOR
← ←
←
ENGINE
TURBO
RESERVOIR
←
←
FIGURE 2 - AD-9 CHARGE CYCLE
OPERATION OF THE AD-9 AIR DRYER
The AD-9 air dryer alternates between two operational modes or cycles during operation: the charge cycle and the purge cycle . The following description of operation is separated into these cycles of operation.
CHARGE CYCLE (refer to Figure 2)
When the compressor is loaded (compressing air) compressed air, along with oil, oil vapor, water and water vapor flows through the compressor discharge line to the supply port of the air dryer end cover. As air travels through the end cover assembly, its direction of flow changes several times, reducing the temperature, causing contaminants to condense and drop to the bottom or sump of the air dryer end cover.
After exiting the end cover, the air flows into the desiccant cartridge. Once in the desiccant cartridge air first flows through an oil separator which removes water in liquid form as well as oil, oil vapor and solid contaminants.
Air exits the oil separator and enters the desiccant drying bed. Air flowing through the column of desiccant becomes
2
← ←
SUPPLY
PORT
← ←
PURGE
VALVE
¬
←
←
←
¬
← ←
← ←
SUMP
CHECK
VALVE
ASSEMBLY
DELIVERY
PORT
EXHAUST
HEATER
ELEMENT progressively dryer as water vapor adheres to the desiccant material in a process known as adsorption . The desiccant cartridge using the adsorption process typically removes 95% of the water vapor from the pressurized air.
The majority of dry air exits the desiccant cartridge through its integral single check valve to fill the purge volume between the desiccant cartridge and outer shell. Some air will also exit the desiccant cartridge through the purge orifice adjacent to the check valve.
Dry air flows out of the purge volume through the single check valve assembly and out the delivery port to the first
(supply) reservoir of the air system.
The air dryer will remain in the charge cycle until air brake system pressure builds to the governor cutout setting.
PURGE CYCLE (refer to Figure 3)
When air brake system pressure reaches the cutout setting of the governor, the compressor unloads (air compression stopped) and the purge cycle of the air dryer begins. When the governor unloads the compressor, it pressurizes the compressor unloader mechanism and line
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DESSICANT
CARTRIDGE
¬
¬
DESSICANT
BED
¬
¬
CHECK
VALVE
¬
¬
ORIFICE
¬
PURGE
VOLUME
OIL
SEPARATOR
¬
CONTROL
PORT
¬
GOVERNOR
¬
COMPRESSOR
¬ ¬ ¬
ENGINE
TURBO
RESERVOIR
SUPPLY
PORT
TURBO
CUTOFF
PISTON
FIGURE 3 - AD-9 PURGE CYCLE connecting the governor unloader port to the AD-9 end cover control port. The purge piston moves in response to air pressure causing the purge valve to open to atmosphere and (partially) closing off the supply of air from the compressor, this will be further discussed in the section covering the turbo cut-off feature. Contaminants in the end cover sump are expelled immediately when the purge valve opens. Also, air which was flowing through the desiccant cartridge changes direction and begins to flow toward the open purge valve. Oil and solid contaminants collected by the oil separator are removed by air flowing from the desiccant drying bed to the open purge valve.
The initial purge and desiccant cartridge decompression lasts only a few seconds and is evidenced by an audible burst of air at the AD-9 exhaust.
The actual reactivation of the desiccant drying bed begins as dry air flows from the purge volume through the desiccant cartridge purge orifice and into the desiccant drying bed. Pressurized air from the purge volume expands after passing through the purge orifice; its pressure is lowered and its volume increased. The flow of dry air through the drying bed reactivates the desiccant material by remov-
PURGE
VALVE
¬ ←
¬
←
←
¬
EXHAUST
←
¬
← ¬
¬
HEATER
ELEMENT
SUMP
CHECK
VALVE
ASSEMBLY
DELIVERY
PORT ing the water vapor adhering to it. Generally 15-30 seconds are required for the entire purge volume of a standard
AD-9 to flow through the desiccant drying bed.
The end cover single check valve assembly prevents air pressure in the brake system from returning to the air dryer during the purge cycle. After the 30 second purge cycle is complete, the air dryer is ready for the next charge cycle to begin.
The purge valve will remain open after the purge cycle is complete and will not close until air brake system pressure is reduced and the governor signals the compressor to charge.
TURBO CUT-OFF FEATURE (Refer to Figure 4)
The primary function of the turbo cut-off valve is to prevent loss of engine turbocharger air pressure through the
AD-9 in systems where the compressor intake is connected to the engine turbocharger. The turbo cut-off valve also reduces the puffing of air out the open exhaust when a naturally aspirated, single cylinder compressor equipped with an inlet check valve is in use.
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UPPER
BRACKET
STRAP
UPPER
BRACKET
DESSICANT
CARTRIDGE
¬ ¬
¬
SUPPLY
PORT
TURBO
CUTOFF
PISTON
←
←
¬
¬
¬
EXHAUST
¬
¬
PURGE
VALVE
DISCHARGE
LINE
CHECK
VALVE
ASSEMBLY
FIGURE 4 - AD-9 TURBO CUTOFF
At the onset of the purge cycle, the downward travel of the purge piston is stopped when the turbo cut-off valve (tapered portion of purge piston) contacts its mating metal seat in the purge valve housing. With the turbo cut-off valve seated (closed position), air in the discharge line and AD-9 inlet port is restricted from entering the air dryer.
While the turbo cut-off effectively prevents loss of turbo charger boost pressure to the engine, some seepage of air may be detected under certain conditions of compressor engine and turbo charger operation, even so there will always be low pressure trapped in the discharge line.
PREVENTIVE MAINTENANCE
Important: Review the warranty policy before performing any intrusive maintenance procedures. An extended warranty may be voided if intrusive maintenance is performed during this period.
Because no two vehicles operate under identical conditions, maintenance and maintenance intervals will vary.
Experience is a valuable guide in determining the best maintenance interval for any one particular operation.
Every 900 operating hours or 25,000 miles or every three (3) months:
1. Check for moisture in the air brake system by opening reservoirs, drain cocks, or valves and checking for presence of water. If moisture is present, the desiccant may require replacement; however, the following conditions can also cause water accumulation and should be considered before replacing the desiccant:
A. An outside air source has been used to charge the system. This air did not pass through the drying bed.
4
DESSICANT
BED
OIL
SEPARATOR
HOUSING
LOWER
BRACKET
CONTROL
PORT
SUPPLY
PORT
CHECK
VALVE
ASSEMBLY
TURBO
CUTOFF
PISTION PURGE VALVE
HOUSING
ASSEMBLY
PURGE
VALVE
DISCHARGE
PORT
FIGURE 5 - AD-9 AIR DRYER SECTIONAL VIEW
B. Air usage is exceptionally high and not normal for a highway vehicle. This may be due to accessory air demands or some unusual air requirement that does not allow the compressor to load and unload
(compressing and non-compressing cycle) in a normal fashion. Check for high air system leakage.
C. The air dryer has been installed in a system that has been previously used without an air dryer. This type system will be saturated with moisture and several weeks of operation may be required to dry it out.
D. Location of the air dryer is too close to the air compressor. Refer to Locating AD-9 On Vehicle section.
E. In areas where more than a 30 degree range of temperature occurs in one day, small amounts of water can accumulate in the air brake system due to condensation. Under these conditions, the presence of small amounts of moisture is normal and should not be considered as an indication that the dryer is not performing properly.
Note: A small amount of oil in the system may be normal and should not, in itself, be considered a reason to replace the desiccant; oil stained desiccant can function adequately.
2. Check mounting bolts for tightness. Retorque to 270-
385 inch pounds.
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3. Perform the Operation & Leakage Tests listed in this publication.
Every 10,800 hours; 300,000 miles or 36 months:
1. Rebuild the air dryer including the desiccant cartridge.
Note: The desiccant change interval may vary from vehicle to vehicle. Although typical desiccant cartridge life is three years, many will perform adequately for a longer period of time. In order to take maximum advantage of desiccant life and assure that replacement occurs only when necessary, it is important that Operation & Leakage
Tests be performed.
OPERATION & LEAKAGE TESTS
1. Test the outlet port check valve assembly by building the air system to governor cut-out and observing a test air gauge installed in the #1 reservoir. A rapid loss of pressure could indicate a failed outlet port check valve.
This can be confirmed by bleeding the system down, removing the check valve assembly from the end cover, subject air pressure to the unit and apply a soap solution to the check valve side. Leakage should not exceed a 1 inch bubble in 1 second.
2. Check for excessive leakage around the purge valve.
With the compressor in loaded mode (compressing air), apply a soap solution to the purge valve housing assembly exhaust port and observe that leakage does not exceed a 1 inch bubble in 1 second. If the leakage exceeds the maximum specified, service the purge valve housing assembly.
3. Close all reservoir drain cocks. Build up system pressure to governor cut-out and note that AD-9 purges with an audible escape of air. Fan the service brakes to reduce system air pressure to governor cut-in. Note that the system once again builds to full pressure and is followed by an AD-9 purge.
4. Check the operation of the safety valve by pulling the exposed stem while the compressor is loaded (compressing air). There must be an exhaust of air while the stem is held and the valve should reseat when the stem is released.
5. Check all lines and fittings leading to and from the air dryer for leakage and integrity.
6. Check the operation of the end cover heater and thermostat assembly during cold weather operation as follows:
A. Electric Power to the Dryer
With the ignition or engine kill switch in the ON position, check for voltage to the heater and thermostat assembly using a voltmeter or test light.
Unplug the electrical connector at the air dryer and place the test leads on each of the pins of the male
AD-9
AIR DRYER
AD-9
END COVER
SIDE VIEW END VIEW
LOWER
MOUNTING
BRACKET
FEMALE
CONNECTOR
MALE
CONNECTOR
LATCH MUST BE
INSERTED UNTIL
IT SNAPS OVER
TAB ON MATING
CONNECTOR
A two lead, 12 inch, wire harness with attached weather resistant connector is supplied with all retrofit and replacement AD-9 Air Dryers. Connect one of the two leads of the wire harness to the engine kill or ignition switch. The remaining lead of the wire harness must be connected to a good vehicle ground. A fuse should be installed in the power carrying wire; install a 10 amp fuse for 12 volt heaters and a 5 amp fuse for a 24 volt heater.
Use 14 AWG wire if it is necessary to lengthen the wire harness provided.
Make certain all wire splices are waterproofed.
Tie wrap or support all electrical wire leading to the
AD-9.
FIGURE 6 - HEATER AND THERMOSTAT CONNECTOR connector. If there is no voltage, look for a blown fuse, broken wires, or corrosion in the vehicle wiring harness. Check to see if a good ground path exists.
B. Thermostat and Heater Operation
Turn off the ignition switch and cool the end cover assembly to below 40 degrees Fahrenheit. Using an ohmmeter, check the resistance between the electrical pins in the female connector. The resistance should be 1.5 to 3.0 ohms for the 12 volt heater assembly and 6.8 to 9.0 ohms for the 24 volt heater assembly. Note : Some early models of the AD-9 will have resistance readings of 1.0 to 2.5
ohms for the 12 volt heater assembly and 4.8 to
7.2 ohms for the 24 volt heater assembly. If the resistance is higher than the maximum stated, replace the purge valve housing assembly, which includes the heater and thermostat assembly.
Warm the end cover assembly to over 90 degrees
Fahrenheit and again check the resistance. The
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3. If the vehicle is equipped with air brakes, make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle.
4. Following the vehicle manufacturers recommended procedures, deactivate the electrical system in a manner that removes all electrical power from the vehicle.
REBUILDING THE AD-9 AIR DRYER
GENERAL
If, after completing the routine operation and leakage tests, it has been determined that one or more components of the air dryer requires replacement or maintenance, refer to the following list to find the appropriate kit(s).
When rebuilding or replacing components of the air dryer use only genuine Bendix parts. For ease in servicing the
AD-9 desiccant cartridge assembly, it is recommended that the air dryer be removed from the vehicle.
MAINTENANCE KITS AVAILABLE:
107798 Purge Valve Housing Maintenance Kit
This kit contains the parts necessary to rebuild the air portion of the purge valve housing and does not include the heater and thermo.
107794 Desiccant Cartridge Replacement Kit
This kit contains the parts necessary to change the desiccant cartridge only.
107796 Remanufactured Desiccant Cartridge
Replacement Kit
This kit contains the parts necessary to change the desiccant cartridge only.
107799 End Cover Check Valve Assembly Replacement
3/4 inch thread size.
107800 End Cover Check Valve Assembly Replacement
1/2 inch thread size.
107896 Service New or Remanufactured Exchange
Purge Valve Housing Assembly
(w/heater and thermo.) 12 volt system.
107897 Service New or Remanufactured Exchange Purge
Valve Housing Assembly
(w/heater and thermo.) 24 volt system.
107695 Complete Mounting Bracket Kit
This kit contains the upper and lower brackets as well as the necessary hardware items to mount them.
IMPORTANT! PLEASE READ
When working on or around a vehicle, the following general precautions should be observed:
1. Park the vehicle on a level surface, apply the parking brakes, and always block the wheels.
2. Stop the engine when working around the vehicle.
5. When working in the engine compartment the engine should be shut off. Where circumstances require that the engine be in operation, EXTREME
CAUTION should be used to prevent personal injury resulting from contact with moving, rotating, leaking, heated, or electrically charged components.
6. Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a component or plug unless you are certain all system pressure has been depleted.
7. Never exceed recommended pressures and always wear safety glasses.
8. Do not attempt to install, remove, disassemble or assemble a component until you have read and thoroughly understand the recommended procedures. Use only the proper tools and observe all precautions pertaining to use of those tools.
9. Use only genuine Bendix replacement parts, components, and kits. Replacement hardware, tubing, hose, fittings, etc. should be of equivalent size, type, and strength as original equipment and be designed specifically for such applications and systems.
10. Components with stripped threads or damaged parts should be replaced rather than repaired. Repairs requiring machining or welding should not be at tempted unless specifically approved and stated by the vehicle or component manufacturer.
11. Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition.
AD-9 REMOVAL
1. Park the vehicle on a level surface and prevent movement by means other than the brakes.
2. Drain all reservoirs to 0 p.s.i. (0 kPa). Caution:
Compressor discharge line may still contain residual pressure.
3. Identify and disconnect the three air lines from the end cover and note the position of end cover ports relative to the vehicle.
4. Unplug the vehicle wiring harness from the heater and thermostat assembly connector on the purge valve housing assembly.
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25
26
28
29
27
24
19
17 23
21
SAFETY
VALVE
20
17
18
1
15
8
11
2
32
4
3
30
FIGURE 7 - AD-9 AIR DRYER ASSEMBLY
31
14
33
10
5
6
7
17
END
COVER
16
13
NOTE: NUMBERS 9 AND 12
NOT USED
1 O-RING
2 EXHAUST DIAPHRAGM
3 1/4" TAPPING SCREW
4 PURGE VALVE LOCK NUT
5 O-RING
6 O-RING
7 O-RING
8 PURGE VALVE ASSEMBLY
10 O-RING
11 PURGE VALVE
13 SPRING
14 O-RING
15 CHECK VALVE ASSEMBLY
16 3/8" CAP SCREW
17 3/8" SPECIAL WASHER
18 3/8" CAP SCREW (LONG)
19 LOCK NUT
20 LOWER MOUNTING BRACKET
21 O-RING
22 DESICCANT CARTRIDGE
COMPLETE
23 O-RING
24 HOUSING
25 5/16" X 4-1/2" UPPER BRACKET
CAP SCREW
26 UPPER BRACKET STRAP
27 UPPER MOUNTING BRACKET
28 5/16" LOCK WASHER
29 5/16" LOCK NUT
30 EXHAUST COVER
31 TORX HEAD BOLT
32 EXHAUST DIAPHRAGM WASHER
33 PURGE PISTON
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5. Loosen the 5/16" X 4-1/2" hex bolt securing the upper mounting strap.
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6. Remove, retain and mark the two 3/8" end cover cap screws, lock nuts and four special washers that retain the lower mounting bracket to the end cover, also mark these two holes of the end cover. (These bolts are longer than the other 6 bolts.)
7. Remove the AD-9 air dryer from its mounting brackets on the vehicle.
DISASSEMBLY
The following disassembly and assembly procedure is presented for reference purposes and presupposes that a major rebuild of the AD-9 is being undertaken. Several replacement parts and maintenance kits are available which do not require full disassembly. The instructions provided with these parts and kits should be followed in lieu of the instructions presented here. Refer to Figure 7 during disassembly.
Caution: While performing service on the AD-9 air dryer, it is not recommended that a clamping device (vise, Cclamp, etc.) be used to hold any die cast aluminum component as damage may result. To hold the end cover, install a pipe nipple in the supply port and clamp the nipple into a vise.
1. Using an adjustable wrench or an 1-3/4" socket, remove the delivery, check valve assembly (15) and o-ring. Remove the o-ring from the check valve assembly.
2. Remove the three 1/4" self tapping screws (3) that secure the purge valve housing assembly to the end cover assembly. Pull the purge valve housing assembly out of the end cover assembly. Remove the three o-rings (5,6
& 7) from the exterior of the purge valve housing assembly. Note: O-rings 5 and 6 may be lodged in the end cover bores, if so, they must be removed
3. Purge Valve Disassembly:
Note: In most cases a flat (non-extended) exhaust cover (30) is used. This cover should be left intact while servicing the purge valve housing assembly. However, if an extended type exhaust cover is in use to accommodate the attachment of an exhaust hose, the exhaust cover must be carefully peeled off the purge valve housing. Use a thin flat blade to pry the exhaust cover off, taking care not to damage the potting material (RTV sealant) under the cover.
To remove the piston from the purge valve housing assembly requires a special Torx head socket or a twelve point 1/4" socket to hold the head of the purge valve bolt (31).
A. Remove the 1/4" nut (4) from the bottom of the purge valve housing assembly using a 9/16" socket
CLEANING & INSPECTION
wrench and a Torx head socket to hold the head of the bolt (31). Remove the diaphragm washer (32)
(if present), and the diaphragm (2) (if present), and the purge valve (11) from the purge valve housing.
B. Remove the 1/4" Torx head bolt (31) from the opposite end, then the purge piston (33), the return spring (13) and two o-rings (10 & 14); one on the
O.D. and the other in the inside of the purge piston.
C. Heater and Thermostat Assembly Replacement.
Caution: Do not attempt to remove this assembly, as it will be damaged during the removal process and is not available as a service part . If the heater and thermostat are defective, replace the entire purge valve housing assembly which includes these items.
4. Remove the remaining six 3/8" cap screws (16), lock nuts (19) and twelve special washers (17) that secure the end cover to the housing (24). Separate the end cover and desiccant cartridge (22) from the housing (24).
5. Remove the end cover to outer