Bendix® AD-IS® EverFlow™ Assembly SD-08-2417

SD-08-2417
Bendix® AD-IS® EverFlow™ Assembly
EVERFLOW™ MODULE
GOVERNOR
EVERFLOW™
ELECTRONIC
MODULE
PURGE RESERVOIR
AD-IS® EVERFLOW™ ASSEMBLY
AD-IS® AIR DRYER
RES
GOVERNOR
RESERVOIR (2)
21
PRI
DELIVERY TO
PRIMARY
RESERVOIR
DESICCANT
CARTRIDGE
MOUNTING
HOLES - 4
PURGE VALVE
PRESSURE
22
SEC
DELIVERY TO
SECONDARY
RESERVOIR
SAFETY VALVE
PURGE
RESERVOIR
MOUNTING
BOLTS (3)
UNL
GOVERNOR
UNLOADER (2)
HEATER /
THERMOSTAT
GOVERNOR
EXH
GOVERNOR
EXHAUST
AD-IS® AIR DRYER
PART NUMBER
STAMPED HERE
1
IN
SUPPLY FROM
COMPRESSOR
PRESSURE PROTECTION
VALVES
23
AUX2
AUXILIARY
DELIVERY PORT
24
AUX1
AUXILIARY
DELIVERY PORTS
FIGURE 1 - AD-IS® EVERFLOW™ ASSEMBLY, AD-IS® AIR DRYER, AND EVERFLOW™ ELECTRONIC MODULE
1
DESCRIPTION
The function of the AD-IS® EverFlow™ assembly is to
provide heavy vehicles that use large amounts of air with
a dryer system that facilitates continuous flow drying. This
assembly provides, in a single package, all the components
necessary to operate two dryers. The assembly determines
if high air demand is needed and continuously switches
between dryers every 30 seconds until the high air demand
ceases. When high air demand is not needed, the assembly
uses the dryers as if in a normal braking system. Each
dryer cycles as the air brake system requires. This feature
prevents wasted air and unnecessary cycles. The assembly
uses an electronic module that determines air demand and
sequences the dryers for maximum efficiency.
The AD-IS® air dryer collects and removes 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, but still may be
mandated by law.
The function of the pressure protection valves is to protect
each reservoir from a pressure loss in the other reservoir or
a pressure loss in an air accessory. Each of the pressure
protection valves in the AD-IS® air dryer may have different
pressure settings, but these are factory set and must not
be changed or adjusted.
The air dryer consists of a “spin on” desiccant cartridge
secured to a base assembly. The base assembly contains
a delivery check valve assembly, safety valve, heater and
thermostat assembly, pressure protection valves, threaded
air connections and the purge valve assembly.
The removable purge valve assembly incorporates the
purge valve mechanism and a turbocharger cut-off feature
that is designed to prevent loss of engine “turbo” boost
pressure during the purge cycle of the AD-IS® air dryer.
For ease of maintenance, all replaceable assemblies
can be serviced without removal of the air dryer from its
mounting on the vehicle. Refer to Preventive Maintenance
section.
These units will not operate properly with a Holset type
compressor. For discharge line unloaded compressors
a three way valve must be installed upstream of the air
dryer. Contact Bendix Commercial Vehicle Systems for
additional information.
AD-IS® EVERFLOW™ ASSEMBLY OPERATION
GENERAL (Refer to Figure 2)
The AD-IS® EverFlow™ assembly is designed to receive
compressed air from the vehicle air compressor. It then
cleans and dries the air before delivering it to the vehicle’s
primary reservoir, secondary reservoir and accessories.
2
Additionally, the AD-IS® EverFlow™ assembly controls the
compressor/dryer charge cycle.
AD-IS® EVERFLOW™ AIR DRYER OPERATION:
GENERAL
The AD-IS® EverFlow™ assembly alternates between the
dryers each time the brake system charges. During high
air demand, the dryers alternate every 30 seconds to allow
drying of the added volume of air. A pressure protection
valve is needed after the dryers to maintain at least 70
PSIG at the dryers during high air demand. An electronic
module monitors the air brake system and determines
the amount of demand. The AD-IS® EverFlow™ assembly
requires a signal from the delivery port of the governor into
the GOV port of the EverFlow™ electronic module. The
AD-IS® EverFlow™ Assembly also needs a supply air line
from the secondary tank to the electronic module RES port.
This line must be 3/8 inch tubing or larger.
The AD-IS® EverFlow™ assembly is primarily designed
to dry air on systems used for bulk unload and central
tire inflation. The system operates best when a pressure
protection valve is installed between the AD-IS® EverFlow™
assembly and the source of the high volume air. Refer to
the system schematics, Figure 2. This pressure protection
valve should have a minimum pressure of 70 PSIG.
Delivery pressure in excess of 175 PSIG can cause
the purge valve to cycle rapidly between load and
purge mode.
NORMAL BRAKE CYCLE (Refer to Figure 2)
When the compressor is charging (compressing air) air
flows through the compressor discharge line to the inlet
(1 IN) port of one of the air dryers. The compressed air
includes contaminates such as oil, oil vapor, water and
water vapor. The air then flows into the desiccant cartridge,
where it flows through a liquid separator which collects
liquids and other contaminants.
Air
Connection
Port ID
Function/Connection
QTY
1
IN
Inlet Port (air in).
1
21
PRI
Delivery Port out (to Primary reservoir)
1
22
SEC
Delivery Port out (to Secondary reservoir)
1
24
AUX 1
Auxiliary Delivery Port (air out).
4
23
AUX 2
Auxiliary Delivery Port (air out).
1
Unloader Control Air (D-2A™ Governor)
Common Reservoir Pressure
(D-2A™ Governor)
2
UNL
RES
TABLE 1 - AD-IS® AIR DRYER PORT DESIGNATIONS
2
EverFlow™ Module
Governor
GOV
RES
CON
3/8"
CON
Schrader
Valve
From
Engine
SEC
RES
1/4"
Supply
IN
CON
CON
CON
1/2"
CON
IN
Primary
Reservoir
1/2"
PRI
OUT
AD-IS® EFM
Secondary
Reservoir
Check
Valve
Supply
IN
Accessories
Compressor
Dryer OUT
CON
CON
EverFlow™
IN
Manual Valve
Pressure
Protection Valve
(Optional)
Bulk Offload CTI
CTI System
Bulk Tanker
Compressor
OUT
Discharge Line
Unloader Valve
Note:
The AD-IS® air dryer purge piston has a purge control channel
drain. This allows any condensation in this area to flow past
a diaphragm in the top of the purge piston and out through a
channel in the middle of the central bolt of the purge assembly
to be drained. During the purge cycle this drain is closed.
FIGURE 2 - AD-IS® AIR DRYER SYSTEM SCHEMATIC
Air then flows into the desiccant drying bed and becomes
progressively drier as water vapor adheres to the desiccant
material in a process known as “ADSORPTION.” Dry air
exits the desiccant cartridge through the delivery check
valve and also through an orifice into the purge reservoir.
The delivery check valve opens, supplying air to pressurize
the air brake system. The purge reservoir stores air that
will be used to reactivate the desiccant during the purge
cycle.
The air dryer will remain in the charge cycle until the air
brake system pressure builds to approximately 85 p.s.i. At
85 p.s.i. the EverFlow™ electronic module is actuated and
begins the purge cycle. When the air pressure reaches
approximately 106 psi, the pressure protection valves
will open and air will be supplied to the primary reservoir,
secondary reservoir or other accessories. If the pressure
protection valves are preset to different values the valves
will open in order of lowest setting to highest setting when
charging a flat system. The air dryer will remain in the
charge cycle until the air brake system pressure builds
to the governor cut-out setting of approximately 130 p.s.i.
When air brake system pressure reaches the cut-out setting
of the governor, the governor unloads the compressor
and the electronic module sends a signal to one of the air
dryers to purge. The governor unloads the compressor by
allowing air pressure to fill the line leading to the compressor
unloader mechanism - causing the delivery of compressed
air to the AD-IS® EverFlow™ assembly to be suspended.
Similarly, the governor also supplies air pressure to the
EverFlow™ electronic module. The electronic module uses
this signal to determine the volume of air into the brake
system. If the volume is normal, the electronic module
sends a signal to the control port on the proper dryer. If the
volume is high, the electronic module switches the dryers
every 30 seconds until the air volume returns to normal.
The air dryer purge piston moves down in response to a
pneumatic signal from the EverFlow™ electronic module,
causing the purge valve to open to the atmosphere and
3
the turbo cut-off valve to close off the supply of air from
the compressor (this will be further discussed in the Turbo
Cut-off Feature section). Water and contaminants which
have collected in the dryer 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.
Liquids and other contaminants collected by the liquid
separator are removed by air flowing from the purge
reservoir through the desiccant 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 one of the AD-IS® EverFlow™ assembly’s
purge exhaust. The actual reactivation of the desiccant
bed begins as dry air from the purge reservoir flows through
the purge orifice into the desiccant bed. Pressurized air
from the purge reservoir expands after passing through
the purge orifice.
The flow of dry air through the drying bed removes water
vapor from the desiccant material. The purge lasts 30
seconds. The delivery check valve assembly prevents air
pressure in the brake system from returning to the purging
air dryer during the purge cycle. After the purge cycle is
complete, the air dryer is ready for the next charge cycle
to begin.
TURBO CUT-OFF FEATURE
The primary function of the turbo cut-off valve is to prevent
loss of engine turbocharger air pressure through the AD-IS®
EverFlow™ assembly when both dryers are in the unloaded
mode. 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 with a soft seat) contacts its
mating metal seat in the purge valve housing. With the turbo
cut-off valve seated (closed position), air in the compressor
discharge line and AD-IS® EverFlow™ assembly inlet port
cannot pass through the air dryer. In this manner the turbo
cut-off effectively maintains turbo charger boost pressure to
the engine. Delivery pressure in excess of 175 PSIG can
cause the purge valve to cycle rapidly between load
and purge mode. All AD-IS® EverFlow™ Assemblies
require a soft seat purge valve.
HIGH VOLUME MODE
If the GOV port of the electronic module indicates that the
compressor has been charging for longer than 30 seconds,
the dryers will alternatively purge every 30 seconds. This
is an indication of high volume through the dryer. When
the governor signal indicates the charge cycle is complete,
the assembly returns to normal brake cycling.
PREVENTIVE MAINTENANCE
Important: Review the warranty policy before performing
any intrusive maintenance procedures. An extended
warranty may be voided if intrusive maintenance is
4
performed during this period. Because no two vehicles
operate under identical conditions, 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 three (3)
months:
1. Check for moisture in the air brake system by opening
reservoir drain valves and checking for presence of
water. If moisture is present, the desiccant cartridges
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.
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. If the vehicle vocation
has changed it may be necessary to upgrade the
compressor size.
C. Discharge line length too short. The minimum line
length from the compressor to the dryer should be:
6' & 1/2" ID On low duty cycle applications (0-20%)
10' & 5/8" ID On high duty cycle applications (20-40%)
D. In areas where more than a 30 degree range of
temperature occurs in one day, small amounts of water
can temporarily accumulate in the air brake system due
to condensation. Under these conditions, the presence
of small amounts of moisture is normal.
Note:
1. Replace both desiccant cartridges at one time. Failure
to change both could cause one dryer to pass wet air
and the other dryer pass dry air. This would lead to a
wet brake system.
2. A small amount of oil in the system is normal and should
not be considered as a reason to replace the desiccant
cartridges. Oil at the dryer purge exhaust is normal.
3. Visually check for physical damage such as chaffed or
broken air and electrical lines and broken or missing
parts.
4. Check the AD-IS® EverFlow™ assembly and purge
reservoir bolts for tightness. See Figure 1. Re-torque
the three air dryer bolts to 360-420 inch pounds and the
four purge reservoir bolts to 300-360 inch pounds.
5. Perform the Operation & Leakage Tests listed in this
publication.
6. The assembly will not operate without electrical power.
Ensure electrical power is at the assembly during
vehicle operation.
WARNING!
This air dryer is intended to remove moisture and other
contaminants normally found in the air brake system. Do
not inject alcohol, anti-freeze, or other de-icing substances
into or upstream of the air dryer. Alcohol is removed by
the dryer, and reduces the effectiveness of the device to
dry air. Use of these or other substances can damage the
air dryer and will void the warranty.
OPERATION & LEAKAGE TESTS
(For additional information order "Air Leakage Video"
BW2327)
1. Check all lines and fittings leading to and from the air
dryer for leakage and integrity. Repair any leaks found.
2. Build up system pressure to governor cut-out and note
that the AD-IS® air dryer purges with an audible escape
of air. Watch the system pressure for leakage for a ten
minute period. If pressure drop exceeds, for a single
vehicle - 1 psi/minute from either service reservoir; or for
tractor trailer - 3 psi/minute from either service reservoir,
inspect the vehicle air systems for sources of leakage
and repair them.
requires the correct electrical voltage to operate
properly.
B. Thermostat and Heater Operation (Refer to Figure
3). NOTE: These tests can only be conducted during
cold weather operation. Turn off the ignition switch
and cool the thermostat and heater assembly to below
40 degrees Fahrenheit. Using an ohmmeter, check
the resistance between the electrical pins in the air
dryer connector half. The resistance should be 1.5 to
3.0 ohms for the 12 volt heater assembly and 6.0 to
9.0 ohms for the 24 volt heater assembly. Warm the
thermostat and heater assembly to approximately 90
degrees Fahrenheit and again check the resistance.
The resistance should exceed 1000 ohms. If the
resistance values obtained are within the stated limits,
the thermostat and heater assembly is operating
properly. If the resistance values obtained are outside
the stated limits, replace the heater and thermostat
assembly.
3. Caution: Be sure to wear safety glasses in case of a
purge blast. Check for excessive leakage around the
purge valve of the dryer, not in the purge cycle, with
the compressor in the loaded mode (compressing air).
Apply a soap solution to the purge valve exhaust port and
observe that leakage does not exceed a 1” bubble in 1
second. If the leakage exceeds the maximum specified,
refer to section entitled Troubleshooting, Symptom 4.
4. Build up system pressure to governor cut-out and note
that one of the AD-IS® EverFlow™ assembly dryers
purges with an audible burst of air, followed immediately
by approximately 30 seconds of air flowing out of the
purge valve. “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
the AD-IS® EverFlow™ assembly other air dryer purge.
If system does not follow this pattern, refer to section
entitled Troubleshooting, Symptoms 1, 2 and 3. Check
the operation of the end cover heater and thermostat
assembly during cold weather operation as follows:
A. Electric Power to the Dryer NOTE: The EverFlow™
assembly should be wired through the ignition and not
the battery. With the ignition or engine kill switch in
the RUN 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 connections of the
female connector on the vehicle power lead. 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. The EverFlow™ assembly
HEATER & THERMOSTAT
CONNECTOR
FIGURE 3 - AD-IS® AIR DRYER HEATER AND
THERMOSTAT CONNECTOR
REBUILDING THE AD-IS® AIR DRYER
GENERAL SAFETY GUIDELINES
WARNING! PLEASE READ AND FOLLOW THESE
INSTRUCTIONS TO AVOID PERSONAL INJURY
OR DEATH:
When working on or around a vehicle, the following
general precautions should be observed at all times.
1. Park the vehicle on a level surface, apply the
parking brakes, and always block the wheels.
Always wear safety glasses.
2. Stop the engine and remove ignition key when
working under or around the vehicle. When
5
working in the engine compartment, the engine
should be shut off and the ignition key should be
removed. 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.
RESULT IN THE AUTOMATIC APPLICATION OF
THE VEHICLE SPRING BRAKES WITHOUT PRIOR
WARNING.
3. 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.
NOTE: Kits are not available for the servicing of the
pressure protection valves (See Figure 4). Do not attempt
to adjust or service the pressure protection valves - these
are not service items.
4. If the work is being performed on the vehicle’s
air brake system, or any auxiliary pressurized air
systems, make certain to drain the air pressure
from all reservoirs before beginning ANY work
on the vehicle. If the vehicle is equipped with
an AD-IS® air dryer system or a dryer reservoir
module, be sure to drain the purge reservoir.
5. Following the vehicle manufacturer’s recommended
procedures, deactivate the electrical system in a
manner that safely removes all electrical power
from the vehicle.
MAINTENANCE KITS
See the proper service data sheet or catalog page for
a full list of maintenance kits available.
•
Governor/Delivery Check Valve Kit: This kit contains
the parts necessary to replace both the governor and
delivery check valve.
•
12 volt or 24 volt Heater and Thermostat Kits:
Contains a replacement heater and thermostat
assembly and related components required for
replacement.
•
Purge Valve Housing Maintenance Kit: This kit
contains the parts necessary to rebuild the purge valve
subassembly.
•
Service New Purge Valve Housing Assembly:
Contains a service new assembly and related
components to change the purge valve subassembly.
•
Service New Desiccant Cartridge Kit: This kit
contains the parts necessary to change the desiccant
cartridge only.
Delivery Check Valve Maintenance Kit: This kit
contains the parts necessary to replace the delivery
check valve.
Pressure Protection Valve Boot Replacement.
AD-IS ® Air Dryer Replacement: Replaces the
complete air dryer assembly. Includes air dryer
assembly and governor.
AD-IS® Air Dryer Splash Shield Replacement Kit.
Purge Reservoir Drain Valve: Replaces the drain
valve on the purge reservoir.
6. Never exceed manufacturer’s recommended
pressures.
7. 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.
8. Use only genuine Bendix® replacement parts,
components and kits. Replacement hardware,
tubing, hose, fittings, etc. must be of equivalent
size, type and strength as original equipment and
be designed specifically for such applications and
systems.
9. Components with stripped threads or damaged
parts should be replaced rather than repaired. Do
not attempt repairs requiring machining or welding
unless specifically stated and approved by the
vehicle and component manufacturer.
10. Prior to returning the vehicle to service, make
certain all components and systems are restored
to their proper operating condition.
11. For vehicles with Antilock Traction Control (ATC),
the ATC function must be disabled (ATC indicator
lamp should be ON) prior to performing any vehicle
maintenance where one or more wheels on a drive
axle are lifted off the ground and moving.
WARNING: DO NOT ATTEMPT TO ADJUST OR SERVICE
THE PRESSURE PROTECTION VALVES. INCORRECT
PRESSURE PROTECTION VALVE SETTINGS CAN
6
•
•
•
•
•
GENERAL
When rebuilding or replacing components of the air dryer
use only genuine Bendix® parts. For ease in servicing,
the AD-IS® air dryer has been designed so that any of the
maintenance kits shown in this manual can be installed
without removing the air dryer from the vehicle. CAUTION:
Always depressurize the air dryer purge reservoir, and all
other reservoirs on the vehicle to 0 p.s.i. before servicing
the air dryer.
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 previous list to find the appropriate kit(s).
vehicle with a limited number of reduced braking capacity
applications before the parking brakes automatically apply
and stay on.
AD-IS®
AIR DRYER
GOVERNORS
ARE NONADJUSTABLE
AND FEATURE A
BREATHER VALVE
IN THIS PORT
ROADSIDE INSPECTION
In the event of a roadside inspection the system behavior
will be as follows: When the system is charged to
governor cut-out, and then one reservoir drain valve is
opened, initially both reservoir gauges will fall, however,
the AD-IS® EverFlow™ assembly primary and secondary
pressure protection valves will close at pressures above
70 psi, protecting the remaining brake circuit from further
loss of pressure.
TEMPORARY AIR DRYER BYPASS
PRESSURE
PROTECTION
VALVE
LOCATIONS
To temporarily bypass the EverFlow ™ assembly, the
following procedure needs to be followed.
FIGURE 4- PRESSURE PROTECTION VALVE LOCATIONS
WARNING:
DO NOT ATTEMPT TO ADJUST OR
SERVICE THE PRESSURE PROTECTION
VALVES. INCORRECT PRESSURE
PROTECTION VALVE SETTINGS CAN
RESULT IN AUTOMATIC APPLICATION
OF VEHICLE SPRING BRAKES WITHOUT
PRIOR WARNING.
TESTING THE AD-IS® EVERFLOW™ ASSEMBLY
Before placing the vehicle in service, perform the following
tests.
1. Close all reservoir drain valves.
2. Build up system pressure to governor cut-out and note
that one AD-IS® air dryer purges with an audible burst of
air, followed immediately by approximately 30 seconds
of air flowing out of the purge valve.
3. “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 a purge at the
other AD-IS® air dryer exhaust.
4. It is recommended that the total air system be tested
for leakage to assure that the AD-IS® air dryer will not
cycle excessively.
See Bendix publication BW5057 “Air Brake Handbook" for
additional information.
BRAKING SYSTEM PROTECTION
The AD-IS® EverFlow™ assembly allows the system to
maintain one brake circuit up to about 100 psi even after
a pressure loss in the other brake circuit. This allows a
vehicle to be moved (in an emergency), but with reduced
braking capacity. Compare this to a conventional system
where a loss of pressure in one service tank leaves the
Follow the General Safety Guidelines outlined on pages
5-6 in this document.
Make sure that all residual pressure has been released and
the air dryer purge reservoir has been drained to 0 p.s.i.,
then remove the air supply line from the compressor to the
inlet port (1 IN). Remove the safety valve from the AD-IS®
air dryer body (see Figure 1 for location). Note that a short
puff of trapped air may vent from the safety valve port when
the valve is being removed. Install a T-fitting into the port.
Using any adapters necessary, reinstall the safety valve
in one of the branches of the T-fitting. Using any adapters
necessary, install the air supply line into the remaining
T-fitting port. After testing the T-fitting for any air leakage,
by using a soap solution after charging to system cut-out
pressure (a 1” bubble in 10 seconds is acceptable), the
vehicle may be returned to temporary service.
Note: This is a temporary bypass of the air dryer, and
full repair of the unit must be carried out at the earliest
opportunity. With the EverFlow™ assembly removed from
the system, contaminants will be entering the air system:
reservoirs will need to be manually drained daily until
the repairs are completed. At end of each working day,
park vehicle and slowly drain pressure through the drain
valves – leave open to the atmosphere, for several hours
if possible. When repairs are carried out, be sure to check
that all reservoirs (including the air dryer purge reservoir)
are emptied of all contaminants.
If after bypassing the EverFlow™ assembly the system
pressure still does not build, use the following procedure
to remove, clean and reinstall the delivery check valve.
DELIVERY CHECK VALVE CLEANING PROCEDURE
(Note: This is only required if system pressure does not
build after temporary bypass is completed.)
Refer to Figure 6 throughout this procedure. Depressurize
the air brake system following the General Safety
7
LOCK TABS
SPLASH
SHIELD
COVER
SPLASH
SHIELD
BRACKET
FIGURE 5 - SPLASH SHIELD BRACKET AND COVER - (EXPLODED VIEW)
Guidelines outlined on pages 5-6 in this document. Also,
always depressurize the air dryer purge reservoir before
servicing the air dryer.
This procedure does not require removal of the AD-IS® air
dryer from the vehicle.
1. Remove the line from governor and mark for easy
reinstallation.
2. Remove the bolts attaching the governor to the AD-IS®
air dryer and retain for reassembly.
3. Remove the governor from the air dryer. Be aware that
a short puff of trapped air may vent when the governor is
removed. Retain the governor gasket for reassembly if
a new governor gasket is not available. Remove and
retain the o-ring from the adapter.
4. The spring/delivery check valve can now be removed.
A second delivery check valve is located in the dryer
without a governor. This check valve is located behind a
hex head plug near the control line from the EverFlow™
module to the air dryer. Carefully remove the hex plug
and follow the instructions that follow.
5. Remove and retain the o-ring from check valve body.
CLEANING & INSPECTION
Consult the service data sheet for the dryer used in your
AD-IS® EverFlow™ assembly. The service data sheet
contains information useful for maintenance and service
of the air dryers.
1. Use a suitable solvent to clean all metal parts, and
use a cotton swab to clean the bore (Note: Do not use
abrasives or tools to clean the bore: any scratches
caused may necessitate replacing the AD-IS ® air
dryer.) Superficial external corrosion and/or pitting is
acceptable.
2. Clean the o-rings with a clean dry cloth. Do not use
solvents.
3. Inspect for physical damage to the bore and the check
valve seat. If the bore is damaged (by scratches etc.
that would prevent delivery check valve from seating),
replace the AD-IS® air dryer.
4. Inspect the delivery check valve, o-rings, etc. for wear
or damage. Replace if necessary using the check valve
replacement kit available at authorized Bendix parts
outlets.
5. Inspect all air line fittings for corrosion and replace as
necessary.
8
GOVERNOR GASKET
(SPECIAL GASKET,
SEE NOTE 6)
SMALL
O-RING
GOVERNOR
(NON-ADJUSTABLE,
130 PSI CUT-OUT)
BOLTS
CHECK VALVE
BODY
SPRING
LARGE
O-RING
ADAPTER
FIGURE 6 - AD-IS® AIR DRYER DELIVERY CHECK VALVE
ASSEMBLY
1. Lubricate the smaller o-ring and check valve body with
barium or silicon grease.
2. Install this o-ring on the check valve body by sliding
the o-ring over the set of 4 tapered guide lands. The
o-ring groove holds the o-ring in its correct location.
3. At the other end of the check valve body, the spring is
installed over the set of 4 straight guide lands. When
the spring has been pushed to the correct location, the
check valve body is designed to hold the end of the
spring in position - be sure that the spring is not loose
before continuing with this installation.
4. Install the assembled check valve body/o-ring/spring
in the delivery port so that the o-ring rests on its seat
and the free end of the spring is visible.
5. Grease the adapter and the remaining larger o-ring and
install it onto the fitting.
6. Position gasket, insert bolts through the governor and
tighten (to 125 in-lbs). (Note: Do not replace with a
standard compressor/governor gasket.)
TESTING THE EVERFLOW™ ASSEMBLY AIR DRYERS
Before placing the vehicle in service, perform the following
tests.
1. Close all reservoir drain valves.
2. Build up system pressure to governor cut-out and note
that one of the AD-IS® EverFlow™ Assembly air dryers
purges with an audible burst of air, followed immediately
by approximately 30 seconds of air flowing out of the
purge valve.
3. “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 a purge at the
other AD-IS® EverFlow™ assembly air dryer exhaust.
4. It is recommended that the total air system be tested for
leakage to assure that the AD-IS® EverFlow™ assembly
air dryers will not cycle excessively.
See Bendix publication BW5057 “Air Brake Handbook.”
7. Reattach line to the governor.
8. Before placing vehicle back into service, check to see
that the system pressure now builds to full operational
pressure.
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METAL
BLACK
RUBBER
HARD SEAT
SOFT SEAT
FIGURE 7- IDENTIFICATION OF HARD AND SOFT SEAT PURGE VALVES
TROUBLESHOOTING THE AD-IS ® EVERFLOW ™
ASSEMBLY
Consult the service data sheet, SD-08-2418, for the dryer
used in your AD-IS® EverFlow™ assembly. The service data
sheet contains information that is useful for maintenance
and service of the air dryers.
1. Excessive dryer purging in the loaded cycle.
• The purge valves in both dryers must have soft-seat
turbo cut-off valves. See Figure 7. Remove the purge
valve an examine the upper window, replace with soft
seat purge valve.
• Excessive pressure (above 175 PSIG) in the
compressor discharge line. Look for obstruction
downstream of the AD-IS® EverFlow™ assembly such
as a pinched line or restrictive valve or fitting.
3. Air brake system will not build air.
• Compressor is undersized.
Some small capacity compressors will not develop
sufficient air delivery at engine idle to allow proper
operation of the AD-IS® EverFlow™ assembly and
charge the air brake system. It may be necessary to
upgrade to a compressor with a higher delivery.
4. Water in downstream reservoirs.
• Dryers not purging. See step 2 - Air dryers do not
purge.
• Desiccant cartridges need to be replaced.
• No pressure protection valve installed downstream
of the air dryers. Refer to Figure 2.
2. Air dryers do not purge.
• Insufficient air pressure in the secondary reservoir.
The EverFlow™ electronic module will not operate until
air pressure in the secondary tank reaches 75 PSIG.
• The check valve in the AD-IS® EverFlow™ supply line
from the secondary tank is installed incorrectly. Refer
to Figure 2.
• The fuse is blown or the air dryer is not connected
to the vehicle electrical system. Check electrical
connection. If the fuse is blown replace the fuse with
a higher amperage fuse. The fuse must be 15 amps
or higher.
• Incorrect voltage. The air dryer voltage must match
the vehicle voltage. Air dryers with a white heater
connector are 12 volt DC and air dryers with a grey
heater connector are 24 volt DC.
BW2077 © 2007 Bendix Commercial Vehicle Systems LLC All rights reserved. 10/2007
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Printed in U.S.A.