School Bus Chassis Maintenance Manual

School Bus Chassis Maintenance Manual
SCHOOL BUS CHASSIS MAINTENANCE MANUAL
Models: Type C SB
FS65
STI-348 (5/06P)
Published by
Freightliner LLC
4747 N. Channel Ave.
Portland, OR 97217
Printed in U.S.A.
Foreword
Scheduled maintenance provides a key element for safe operation of your vehicle. A proper
maintenance program also helps to minimize downtime and to safeguard warranties. This
maintenance manual provides information necessary for years of safe, reliable, and cost-efficient
vehicle operation.
Perform daily pretrip inspection and maintenance as outlined in the vehicle operator’s manual.
Perform the operations in this maintenance manual at scheduled intervals based upon distance
traveled or months of operation. Your authorized servicing dealer has the qualified technicians
and equipment to perform this maintenance for you. Your dealership can also set up a scheduled
maintenance program tailored specifically to your needs. Optionally, your dealership can assist
you in learning how to perform the maintenance procedures in this manual.
IMPORTANT: Descriptions and specifications in this manual were in effect at the time of
printing. Freightliner Custom Chassis Corporation (FCCC) reserves the right to discontinue models at any time, or change specifications and design without notice and
without incurring obligation.
For additional information, please contact Freightliner LLC, Service Systems and Documentation, P.O. Box 3849, Portland, OR 97208-3849, U.S.A. or refer to http://www.Freightliner.com and
http://www.FreightlinerChassis.com.
Environmental Concerns and Recommendations
Whenever you see instructions in this manual to discard materials, you should attempt to reclaim
and recycle them. To preserve our environment, follow appropriate environmental rules and
regulations when disposing of materials.
NOTICE: Parts Replacement Considerations
Do not replace suspension, axle, or steering parts (such as springs, wheels, hubs, and steering
gears) with used parts. Used parts may have been subjected to collisions or improper use and
have undetected structural damage.
© 1996-2006 Freightliner LLC
All rights reserved. No part of this publication, in whole or in part, may be translated, reproduced,
stored in a retrieval system, or transmitted in any form by any means, electronic, mechanical,
photocopying, recording, or otherwise, without the prior written permission of Freightliner LLC.
Freightliner LLC
Service Systems and Documentation (POC-SSD)
P.O. Box 3849
Portland, OR 97208–3849
Introduction
Descriptions of Service Publications
Freightliner LLC distributes the following major service publications.
Workshop Manual
Workshop manuals contain service and repair information for all vehicle systems and components, except for major components such as engines, transmissions, and rear axles. Each workshop manual section is divided into subjects
that can include general information, principles of operation, removal, disassembly, assembly, installation, specifications, and troubleshooting.
Maintenance Manual
Maintenance manuals contain routine maintenance procedures and intervals for
vehicle components and systems. They have information such as lubrication
procedures and tables, fluid replacement procedures, fluid capacities, specifications, procedures for adjustments and for checking the tightness of fasteners.
Maintenance manuals do not contain detailed repair or service information.
Operator’s Manual
Operator’s manuals contain information needed to enhance the driver’s understanding of how to operate and care for the vehicle and its components. Each
manual contains a chapter that covers pretrip inspection and daily maintenance
of vehicle components. Operator’s manuals do not contain detailed repair or
service information.
Parts Technical Manual
Freightliner LLC publishes this manuals to aid in the identification of serviceable
replacement vehicle parts. This manual is used in conjunction with the parts
book and the service parts catalog microfiche.
Service Bulletins
Service Bulletins provide the latest service tips, field repairs, product improvements, and related information. Some service bulletins are updates to information in the workshop manual. These bulletins take precedence over workshop
manual information, until the latter is updated; at that time, the bulletin is usually
canceled. The service bulletins manual is available only to dealers. When doing
service work on a vehicle system or part, check for a valid service bulletin for
the latest information on the subject.
IMPORTANT: Before using a particular service bulletin, check the current
service bulletin validity list to be sure the bulletin is valid.
Recall Bulletins
These bulletins pertain to special situations that involve service work or replacement of parts in connection with a recall notice. Recall bulletins pertain to matters of vehicle safety. All bulletins are distributed to dealers; customers receive
notices that apply to their vehicles.
Field Service
Modifications
This publication is concerned with non-safety-related service work or replacement of parts. All field service modifications are distributed to dealers; customers receive notices that apply to their vehicles.
School Bus Chassis Maintenance Manual, November 2002
I–1
Introduction
Page Description
For a page example of the printed manual, see Fig. 1.
A
B
C
32
Suspension
32−01 Suspension Inspecting,
Freightliner Spring
FRONT AND REAR SUSPENSION SPRING
ASSEMBLIES
REAR SUSPENSION
32−01 U−Bolt Torque Checking,
Freightliner Spring
Suspension
REAR SUSPENSION SPRING BRACKETS
32−02 Suspension Lubricating,
Freightliner Spring
FRONT SUSPENSION
32/1
School Bus Chassis Maintenance Manual, October 1996
D
E
f020053
09/16/96
A.
B.
C.
D.
E.
Maintenance Operation Number consists of the Group Number followed by the Sequence Number
Group Title
Group Number
Release Date
Group Number/Page Number
Fig. 1, Page Example of the Printed Manual
I–2
School Bus Chassis Maintenance Manual, November 2002
Introduction
Maintenance Manual Contents
Group No.
Group Title
00 . . . . . . . . . . . . . . . . . . . . . . General Information
01 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Engine
09 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Air Intake
15 . . . . . . . . . . . . . . . . . . . Alternators and Starters
20 . . . . . . . . . . . . . . . . . . . Engine Cooling/Radiator
25 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Clutch
26 . . . . . . . . . . . . . . . . . . . . . . . . . . . Transmission
31 . . . . . . . . . . . . . Frame and Frame Components
32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . Suspension
33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Front Axle
35 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rear Axle
40 . . . . . . . . . . . . . . . . . . . . . . . . Wheels and Tires
41 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Driveline
42 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Brakes
46 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Steering
47 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fuel
49 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Exhaust
54 . . . . . . . . . . Electrical, Instruments, and Controls
School Bus Chassis Maintenance Manual, November 2002
I–3
General Information
00
Index, Alphabetical
Title of Maintenance Operation (MOP)
MOP Number
Determining Scheduled Maintenance Intervals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00–01
Initial Maintenance (IM) Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00–06
Lubrication and Fluid Level Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00–04
M1 Maintenance Interval Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00–07
M2 Maintenance Interval Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00–08
M3 Maintenance Interval Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00–09
Maintenance Interval Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00–03
Maintenance Operation Sets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00–05
Metric/U.S. Customary Conversion Table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00–12
Noise Emission Controls Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00–10
Torque Specifications Tables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00–13
Vehicle Maintenance Schedule Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00–02
Verification of Inspections Log. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00–11
School Bus Chassis Maintenance Manual, October 2005
00
General Information
Determining Scheduled Maintenance Intervals: 00–01
Description
Category I (urban transport) applies to vehicles that
annually travel up to 20,000 miles (32 000 kilometers).
Category II (rural transport) applies to vehicles that
annually travel over 20,000 miles (32 000 kilometers).
The table under Vehicle Maintenance Schedule Table
shows the two categories of vehicle usage. For each
category, the appropriate distance and time intervals
are given for performing Initial Maintenance and for
repeating each maintenance operation set (M1
through M3).
The table under Maintenance Interval Tableshows
which maintenance operation set must be performed
at the actual distances (miles and kilometers) or actual months of operation for each maintenance category. The schedule of actual distances (and
months) is based on the intervals given in the Vehicle Maintenance Schedule Table.
The table under Maintenance Operation Setslists, in
numerical order, the text reference numbers and descriptions of all maintenance operations, and indicates all maintenance operation sets at which each
operation must be performed.
nance Interval Operations table. Use the maintenance operation reference numbers to find
instructions in the manual for completion of each operation.
Complete each maintenance operation set at the required interval. Then, when you have completed
maintenance operation set M3 under the 12th Maintenance Number listed in the Maintenance Interval
Table, repeat the pattern. The 13th Maintenance
Number will begin at maintenance operation set M1,
under the 1st Maintenance Number listed in the
Maintenance Interval Table.
NOTE: When performing operations for the 13th
Maintenance Number, complete the M1 operations only, not the Initial Maintenance operations.
To determine the distance/months for the 13th Maintenance Number, add your category’s
distance/months for the 1st Maintenance Number to
the distance/months for the 12th Maintenance Number, then perform the operations listed in the applicable table in the Maintenance Interval Operations
tables. For the 14th Maintenance Number, add the
distance/months for the 2nd to the distance/months
for the 12th; continue this pattern for each successive Maintenance Number.
Each Maintenance Interval Operations table (IM
through M3) lists the appropriate text reference numbers and descriptions of only those maintenance operations that must be performed at that maintenance
operation set. Each maintenance operation set is
listed in a separate Maintenance Interval Operations
table.
Use
Before placing your new vehicle in service, determine
the maintenance category (Category I or II) that applies to your intended use of the vehicle. See the
Vehicle Maintenance Schedule Table to determine
the distance (or time) interval at which each maintenance operation set must be performed for your category of vehicle.
When the vehicle reaches the actual distance (or
months) given for an interval, see the Maintenance
Interval Table to find the maintenance operation set
that applies to that interval. Then perform the maintenance operations listed in the applicable Mainte-
School Bus Chassis Maintenance Manual, October 2005
00/1
00
General Information
Vehicle Maintenance Schedule Table: 00–02
Vehicle Maintenance Schedule Table
Description
CATEGORY I
(Urban Transport)
vehicles that annually travel up to
20,000 miles (32 000 km)
CATEGORY II
(Rural Transport)
vehicles that annually travel over 20,000
miles (32 000 km)
00/2
Maintenance Operation Set
Maintenance Intervals
Frequency
Miles
km
Months
Initial Maintenance (IM)
first
2500
4000
3
Maintenance 1 (M1)
every
2500
4000
3
Maintenance 2 (M2)
every
10,000
16 000
12
Maintenance 3 (M3)
every
30,000
48 000
36
Initial Maintenance (IM)
first
5000
8000
3
Maintenance 1 (M1)
every
5000
8000
3
Maintenance 2 (M2)
every
20,000
32 000
12
Maintenance 3 (M3)
every
60,000
96 500
36
School Bus Chassis Maintenance Manual, October 2005
00
General Information
Maintenance Interval Table: 00–03
Maintenance Interval Table
Category I
Category II
Maint. No.
Maint. Oper.
Set
miles x 100
km x 100
months
miles x 100
km x 100
months
1st
IM + M1
25
40
3
50
80
3
2nd
M1
50
80
6
100
160
6
3rd
M1
75
120
9
150
240
9
4th
M2
100
160
12
200
320
12
5th
M1
125
200
15
250
400
15
6th
M1
150
240
18
300
480
18
7th
M1
175
280
21
350
560
21
8th
M2
200
320
24
400
640
24
9th
M1
225
360
27
450
720
27
10th
M1
250
400
30
500
800
30
11th
M1
275
440
33
550
885
33
12th
M3
300
480
36
600
965
36
School Bus Chassis Maintenance Manual, October 2005
00/3
00
General Information
Lubrication and Fluid Level Check: 00–04
Lubrication and Fluid Level Check
Maintenance
Operation
Reference
Number
Maintenance Operation Description
25–01
Clutch Release Bearing Lubricating
25–02
Clutch Release Cross-Shaft Lubricating
26–01
Eaton/Fuller Transmission Oil Level Checking
26–05
Allison Transmission Fluid Level Checking
32–02
Suspension Lubricating, Freightliner Spring
33–01
Knuckle Pin Lubricating
33–02
Tie-Rod End Lubricating
33–05
Oil-Filled Hubs Oil Level Checking
35–01
Axle Lubricant Level Checking
41–01
Driveline Inspecting and Lubricating
42–04
Air Reservoir Automatic Drain Valve Disassembling, Cleaning, and
Inspecting, Bendix DV–2
42–05
Automatic Slack Adjuster Lubricating and Checking, Meritor
42–09
Camshaft Bracket Bushing Lubricating
42–14
Brake Caliper Slide Pin Lubricating, Bosch Brakes
42–15
Brake Caliper Slide Rail Lubricating, Bosch Brakes
46–01
Steering Driveline Lubricating
46–02
Drag Link Lubricating
46–03
Power Steering Reservoir Fluid Level Checking
46–05
Steering Gear Lubricating
54–01
Ground Cables Checking and Cleaning
Table 1, Lubrication and Fluid Level Check
00/4
School Bus Chassis Maintenance Manual, October 2005
00
General Information
Maintenance Operation Sets: 00–05
NOTE: Maintenance operations appearing in italics in
this table are for noise emission control components.
Numbers in this table are maintenance operation ref-
erence numbers matching those in the text of this
manual.
REQUIRED MAINTENANCE OPERATION SET
IM M1 M2 M3
Maintenance Operation Reference Number and Maintenance Operation
00–04 Lubrication and Fluid Level Check
•
•
•
•
•
•
•
•
01–01 Engine-Support Fasteners Checking
•
01–02 Engine Drive Belt Inspecting
01–03 Pacbrake Inspecting and Maintenance*
09–01 Air Cleaner Element Inspecting
•
•
09–02 Air Cleaner Element Replacing
•
•
15–01 Alternator, Battery, and Starter Checking
•
•
20–01 Radiator Cap Checking
•
•
20–02 Radiator Pressure Flushing and Coolant Changing
•
20–03 Eaton Viscous Fan Drive Checking
•
•
25–01 Clutch Release Bearing Lubricating
•
•
•
•
25–02 Clutch Release Cross-Shaft Lubricating
•
•
•
•
•
•
26–01 Eaton/Fuller Transmission Oil Level Checking
26–02 Eaton/Fuller Transmission Oil Changing and Magnetic Plug Cleaning
•
•
26–03 Transmission Breather Checking
•
26–04 Allison Transmission Fluid and Filter Changing†
•
•
26–05 Allison Transmission Fluid Level Checking
•
•
•
31–01 Frame Fastener Torque Checking
•
32–01 Suspension Inspecting, Freightliner Spring
•
•
•
•
32–02 Suspension Lubricating, Freightliner Spring
•
•
•
•
32–03 U-Bolt Torque Checking, Freightliner Spring
•
•
32–04 Spring Bracket Fastener Torque Checking, Freightliner Spring (Rear)
•
•
32–05 Fastener Torque Checking, Freightliner AirLiner
•
•
32–06 Component Clearance Checking, Freightliner AirLiner
•
•
•
•
•
32–07 Component Inspecting and Operation Checking, Freightliner AirLiner
32–08 U-Bolt Torque Checking, Freightliner AirLiner
•
32–09 Shock Absorber Checking, Freightliner Spring
•
32–10 Radius Rod Bushing Checking, Hendrickson
•
32–11 Control Rod Checking, Freightliner AirLiner
•
•
•
32–12 Fastener Torque Checking, Hendrickson
•
•
33–01 Knuckle Pin Lubricating
•
•
•
•
33–02 Tie-Rod End Lubricating
•
•
•
•
33–03 Tie-Rod End Inspecting
•
•
•
•
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00
General Information
Maintenance Operation Sets: 00–05
REQUIRED MAINTENANCE OPERATION SET
IM M1 M2 M3
Maintenance Operation Reference Number and Maintenance Operation
33–04 All-Axle Alignment Checking
•
33–05 Oil-Filled Hubs Oil Level Checking
•
•
•
33–06 Oil-Filled Hubs Oil Changing
•
33–07 Wheel Bearing Removing, Cleaning, Checking, Repacking, and Adjusting
•
35–01 Axle Lubricant Oil Level Checking
•
35–02 Axle Lubricant Changing and Magnetic Plug Cleaning
•
35–03 Axle Breather Checking
•
•
•
•
•
40–01 Wheel Nut and Rim Nut Checking
•
•
41–01 Driveline Inspecting and Lubricating
•
•
42–01 Air Dryer Checking, Bendix AD–9‡
•
•
•
•
•
•
•
•
42–02 Air Dryer Desiccant Replacing, Bendix AD–9
•
42–03 Air Dryer Inspecting, Bendix AD–9‡
•
42–04 Air Reservoir Automatic Drain Valve Disassembling, Cleaning, and Inspecting, Bendix DV–2
42–05 Automatic Slack Adjuster Lubricating and Checking, Meritor
•
•
•
•
42–06 Bendix Hydro-Max Power Booster Checking
•
•
•
•
42–07 Brake Lines Checking, Hydraulic Disc Brakes
•
•
•
•
42–08 Brake Lining Wear Checking, Hydraulic Disc Brakes
•
•
•
•
•
•
42–09 Camshaft Bracket Bushing Lubricating
42–10 Foot Brake Valve Actuator Lubricating, Bendix E–6
•
•
•
42–11 Relay Valve Checking, Midland
•
•
•
•
42–12 Front Air Brake Hose Inspecting
•
•
•
•
42–13 ABS Tone Rings Cleaning§
•
•
•
•
46–01 Steering Driveline Lubricating
•
•
•
•
46–02 Drag Link Lubricating
•
•
•
•
46–03 Power Steering Reservoir Fluid Level Checking
•
•
•
42–14 Brake Caliper Slide Pin Lubricating, Bosch Brakes¶
42–15 Brake Caliper Slide Rail Lubricating, Bosch Brakes**
46–04 Power Steering Reservoir Fluid and Filter Changing
46–05 Steering Gear Lubricating
•
•
•
47–01 Inline Fuel Strainer Replacing, Cummins ISB02 and MBE900 Engines
•
•
49–01 Exhaust System Inspecting
•
•
54–01 Ground Cables Checking and Cleaning
•
•
00/6
•
•
School Bus Chassis Maintenance Manual, October 2005
00
General Information
Maintenance Operation Sets: 00–05
REQUIRED MAINTENANCE OPERATION SET
IM M1 M2 M3
Maintenance Operation Reference Number and Maintenance Operation
54–02 Electrical Wiring Checking
•
•
* With frequent use, the Pacbrake Exhaust Brake will operate free of maintenance. However, if the vehicle is used inconsistently, seasonally, or is exposed to
excess moisture, it will be necessary to perform preventative maintenance as instructed in Maintenance Operation 01–03.
† For series 2000/2400 transmissions with non-TranSynd ATF, change oil and filters at 50,000 miles (80 000 km) or 24 months, whichever comes first.
‡ Perform annually during the fall.
§ This operation applies specifically to vehicles used during winter months in areas where corrosive materials are used on the highways.
¶ See the "Bosch Pin Slide Disc Brakes Service Manual" for more information.
** Lubricate every 6 months OR every 18,000 miles (28 800 km), whichever comes first.
School Bus Chassis Maintenance Manual, October 2005
00/7
00
General Information
Initial Maintenance (IM) Operations: 00–06
This Initial Maintenance (IM) Operations table lists all
maintenance operations that are to be performed at
initial maintenance (IM). Numbers in this table are
maintenance operation reference numbers matching
those in the text of this manual, that can be used to
find detailed instructions for the operations to be performed. All operations listed in the table, along with
the operations listed in the M1 Maintenance Interval
Operations table, must be performed to complete the
initial maintenance (IM).
Initial Maintenance (IM) Operations
Maint.
Oper. No.
00/8
Initial Maintenance (IM) Operations
00–07
Perform all M1 Operations
26–02
Eaton/Fuller Transmission Oil Changing and Magnetic Plug Cleaning
31–01
Frame Fastener Torque Checking
32–03
U-Bolt Torque Checking, Freightliner Spring
32–04
Spring Bracket Fastener Torque Checking, Freightliner Spring (Rear)
32–05
Fastener Torque Checking, Freightliner AirLiner
32–06
Component Clearance Checking, Freightliner AirLiner
32–08
U-Bolt Torque Checking, Freightliner AirLiner
33–04
All-Axle Alignment Checking
35–02
Axle Lubricant Changing and Magnetic Plug Cleaning
42–03
Air Dryer Inspecting, Bendix AD–9
42–10
Foot Brake Valve Actuator Lubricating, Bendix E–6
School Bus Chassis Maintenance Manual, October 2005
00
General Information
M1 Maintenance Interval Operations: 00–07
This M1 Maintenance Interval Operations table lists
all maintenance operations that are to be performed
at the M1 maintenance interval. Numbers in this
table are maintenance operation reference numbers
matching those in the text of this manual, that can be
used to find detailed instructions for the operations to
be performed.
M1 Maintenance Interval Operations
Maint.
Oper. No.
00–04
M1 Maintenance Interval Operations
Lubrication and Fluid Level Check (includes the following):
• Clutch Release Bearing Lubricating
• Clutch Release Cross-Shaft Lubricating
• Eaton/Fuller Transmission Oil Level Checking
• Allison Transmission Fluid Level Checking
• Suspension Lubricating, Freightliner Spring
• Knuckle Pin Lubricating
• Tie-Rod End Lubricating
• Axle Lubricant Level Checking
• Driveline Inspecting and Lubricating
• Automatic Slack Adjuster Lubricating and Checking, Meritor
• Steering Driveline Lubricating
• Drag Link Lubricating
• Power Steering Reservoir Fluid Level Checking
• Steering Gear Lubricating
• Oil-Filled Hubs Oil Level Checking
09–01
Air Cleaner Element Inspecting
32–01
Suspension Inspecting, Freightliner Spring
32–11
Control Rod Checking, Freightliner AirLiner
33–03
Tie-Rod End Inspecting
35–03
Axle Breather Checking
42–06
Bendix Hydro-Max Power Booster Checking
42–07
Brake Lines Checking, Hydraulic Disc Brakes
42–08
Brake Lining Wear Checking, Hydraulic Disc Brakes
42–11
Relay Valve Checking, Midland
42–12
Front Air Brake Hose Inspecting
42–13
ABS Tone Rings Cleaning
School Bus Chassis Maintenance Manual, October 2005
00/9
00
General Information
M2 Maintenance Interval Operations: 00–08
This M2 Maintenance Interval Operations table lists
all maintenance operations that are to be performed
at the M2 maintenance interval. Numbers in this
table are maintenance operation reference numbers
matching those in the text of this manual, that can be
used to find detailed instructions for the operations to
be performed. Perform all M1 maintenance interval
operations at the M2 maintenance interval.
M2 Maintenance Interval Operations
Maint.
Oper. No.
M2 Maintenance Interval Operations
00–07
Perform all M1 Operations
01–02
Engine Drive Belt Inspecting
09–02
Air Cleaner Element Replacing
15–01
Alternator, Battery, and Starter Checking
20–01
Radiator Cap Checking
20–03
Eaton Viscous Fan Drive Checking
26–03
Transmission Breather Checking
42–01
Air Dryer Checking, Bendix AD–9*
42–03
Air Dryer Inspecting, Bendix AD–9*
42–04
Air Reservoir Automatic Drain Valve Disassembling, Cleaning, and
Inspecting, Bendix DV–2
42–09
Camshaft Bracket Bushing Lubricating
42–10
Foot Brake Valve Actuator Lubricating, Bendix E–6
47–01
Inline Fuel Strainer Replacing, Cummins ISB02 and MBE900 Engines
49–01
Exhaust System Inspecting
54–01
Ground Cables Checking and Cleaning
54–02
Electrical Wiring Checking
* Perform annually during the fall.
00/10
School Bus Chassis Maintenance Manual, October 2005
00
General Information
M3 Maintenance Interval Operations: 00–09
This M3 Maintenance Interval Operations table lists
all maintenance operations that are to be performed
at the M3 maintenance interval. Numbers in this
table are maintenance operation reference numbers
matching those in the text of this manual, that can be
used to find detailed instructions for the operations to
be performed. Perform all M1 maintenance interval
operations and M2 maintenance interval operations
at the M3 maintenance interval.
M3 Maintenance Interval Operations
Maint.
Oper. No.
M3 Maintenance Interval Operations
00–07
Perform all M1 Operations
00–08
Perform all M2 Operations
01–01
Engine-Support Fasteners Checking
20–02
Radiator Pressure Flushing and Coolant Changing
26–02
Eaton/Fuller Transmission Oil Changing and Magnetic Plug Cleaning
26–04
Allison Transmission Fluid and Filter Changing
31–01
Frame Fastener Torque Checking
32–03
U-Bolt Torque Checking, Freightliner Spring
32–04
Spring Bracket Fastener Torque Checking, Freightliner Spring (Rear)
32–05
Fastener Torque Checking, Freightliner AirLiner
32–06
Component Clearance Checking, Freightliner AirLiner
32–07
Component Inspecting and Operation Checking, Freightliner AirLiner
32–08
U-Bolt Torque Checking, Freightliner AirLiner
32–09
Shock Absorber Checking, Freightliner Spring
32–10
Radius Rod Bushing Checking, Hendrickson
32–12
Fastener Torque Checking, Hendrickson
33–06
Oil-Filled Hubs Oil Changing
33–07
Wheel Bearings Removing, Cleaning, Checking, Repacking, and Adjusting
35–02
Axle Lubricant Changing and Magnetic Plug Cleaning
40–01
Wheel Nut and Rim Nut Checking
42–02
Air Dryer Desiccant Replacing, Bendix AD–9
46–04
Power Steering Reservoir Fluid and Filter Changing
School Bus Chassis Maintenance Manual, October 2005
00/11
00
General Information
Noise Emission Controls Maintenance: 00–10
General Information
Federal Law, Part 205: Transportation
Equipment Noise Emission Controls
Part 205, Transportation Equipment Noise Emission
Controls, requires the vehicle manufacturer to furnish, with each new vehicle, such written instructions
for the proper maintenance, use, and repair of the
vehicle by the ultimate purchaser to provide reasonable assurance of the elimination or minimization of
noise emission degradation throughout the life of the
vehicle. In compliance with the law, the noise emission controls maintenance information located in
each applicable group of this manual, in conjunction
with the vehicle workshop manual, provides these
instructions to owners.
Normal Vehicle Use
The maintenance instructions contained in this
manual are based on average vehicle use and normal operating conditions. Unusual vehicle operating
conditions may require service at more frequent intervals.
Recommendations for Replacement
Parts
Replacement parts used for maintenance or repair of
noise emission controls should be genuine Freightliner Custom Chassis Corporation (FCCC) parts. If
other than genuine FCCC parts are used for replacement or repair of components affecting noise emission control, the owner should be sure that such
parts are warranted by their manufacturer to be
equivalent to genuine FCCC parts in performance
and durability.
the purpose of noise control prior to its sale or delivery to the ultimate purchaser or while it is in use, or
(2) the use of the vehicle after such device or element of design has been removed or rendered inoperative by any person. Among those acts presumed
to constitute tampering are the acts listed below:
A. Removal of engine noise-deadening panels.
B. Removal of, or rendering inoperative, the engine
speed governor so as to allow engine speed to
exceed manufacturer’s specifications.
C. Removal of, or rendering inoperative, the fan
clutch, including by-passing the control on any
thermostatic fan drive to cause it to operate continuously.
D. Removal of the fan shroud.
E. Removal of, or rendering inoperative, exhaust
system components, including exhaust pipe
clamping.
F.
Removal of air intake components.
G. Removal of hood liners (noise-deadening panels).
Maintenance Instructions
Scheduled intervals are in the maintenance table in
this Group. A "Verification of Inspections Log" follows,
and should be filled in each time the noise emission
controls on the vehicle are maintained or repaired.
Freightliner Noise Emissions Warranty
See the vehicle owner’s warranty information book
for warranty information concerning noise emission
controls.
Tampering With the Noise Controls is
Prohibited
Federal law prohibits the following acts or the causing thereof: (1) the removal or rendering inoperative
by any person other than for purposes of maintenance, repair, or replacement, of any device or element of design incorporated into any new vehicle for
00/12
School Bus Chassis Maintenance Manual, October 2005
00
General Information
Verification of Inspections Log: 00–11
Verification of Inspections Log
Verification of Inspections Log
Date
Mileage
Repair Description
Cost
Repair Facility
Group 01 — Engine Support Fasteners
Group 20 — Engine Cooling Fan Drive
Group 49 — Exhaust System
School Bus Chassis Maintenance Manual, October 2005
00/13
00
General Information
Metric/U.S. Customary Conversion Table: 00–12
When You Know U.S.
Customary
Multiply
By
To Get Metric
When You
Know Metric
Multiply
By
To Get U.S. Customary
Length
inches (in)
25.4
millimeters (mm)
0.03937
inches (in)
inches (in)
2.54
centimeters (cm)
0.3937
inches (in)
feet (ft)
0.3048
meters (m)
3.281
feet (ft)
yards (yd)
0.9144
meters (m)
1.094
yards (yd)
miles (mi)
1.609
kilometers (km)
0.6215
miles (mi)
square inches (in2)
645.16
square millimeters (mm2)
0.00155
square inches (in2)
square inches (in2)
6.452
square centimeters (cm2)
0.155
square inches (in2)
square feet (ft2)
0.0929
square meters (m2)
10.764
cubic inches (in3)
16387.0
cubic millimeter (mm3)
0.000061
cubic inches (in3)
cubic inches (in3)
16.387
cubic centimeters (cm3)
0.06102
cubic inches (in3)
cubic inches (in3)
0.01639
liters (L)
61.024
cubic inches (in3)
fluid ounces (fl oz)
29.54
milliliters (mL)
0.03381
pints (pt)
0.47318
liters (L)
2.1134
pints (pt)
quarts (qt)
0.94635
liters (L)
1.0567
quarts (qt)
Area
square feet (ft2)
Volume
fluid ounces (fl oz)
gallons (gal)
3.7854
liters (L)
0.2642
cubic feet (ft3)
28.317
liters (L)
0.03531
cubic feet (ft3)
gallons (gal)
cubic feet (ft3)
0.02832
cubic meters (m3)
35.315
cubic feet (ft3)
Weight/Force
ounces (av) (oz)
28.35
grams (g)
0.03527
ounces (av) (oz)
pounds (av) (lb)
0.454
kilograms (kg)
2.205
pounds (av) (lb)
U.S. tons (t)
907.18
kilograms (kg)
0.001102
U.S. tons (t)
U.S. tons (t)
0.90718
metric tons (t)
1.1023
U.S. tons (t)
Torque/Work Force
inch–pounds (lbf·in)
11.298
Newton–centimeters (N·cm)
0.08851
inch–pounds (lbf·in)
foot–pounds (lbf·ft)
1.3558
Newton–meters (N·m)
0.7376
foot–pounds (lbf·ft)
3.37685
kilo Pascals (kPa)
0.29613
inches of mercury (inHg)
kilo Pascals (kPa)
0.14503
pounds per square inch (psi)
Pressure/Vacuum
inches of mercury (inHg)
pounds per square inch (psi) 6.895
Table 2, Metric/U.S. Customary Conversion Table
00/14
School Bus Chassis Maintenance Manual, October 2005
00
General Information
Torque Specifications Tables: 00–13
IMPORTANT: Grade 8 regular hex zinc-yellow plated
capscrews and cadmium- and wax-coated prevailing
torque locknuts may be tightened to a lower torque
value than the grade 8 regular hex fasteners de-
scribed in Table 3. See Table 4 for torque values for
grade 8 regular hex zinc-yellow plated capscrews
and cadmium- and wax-coated prevailing torque
locknuts.
Torque Values for U.S. Customary Thread Fasteners With Lubricated* or Plated Threads†
Regular Hex
Thread
Diameter–
Pitch
Grade 5
Bolt
Grade 5 or
B Nut
Grade 8 or
8.2 Bolt
Torque: lbf·ft (N·m)
f230003
f230002
1/4–20
Flanged
7 (9)
Grade 8 or
C Nut
Torque: lbf·ft (N·m)
f230004
8 (11)
f230005
Grade 5
Bolt
Grade B
Nut
Torque: lbf·ft (N·m)
f230006
f230007
Grade 8 or
8.2 Bolt
Grade G
Nut
Torque: lbf·ft (N·m)
f230009
f230008
6 (8)
10 (14)
1/4–28
8 (11)
9 (12)
7 (9)
12 (16)
5/16–18
15 (20)
16 (22)
13 (18)
21 (28)
5/16–24
16 (22)
17 (23)
14 (19)
23 (31)
3/8–16
26 (35)
28 (38)
23 (31)
37 (50)
3/8–24
30 (41)
32 (43)
25 (34)
42 (57)
7/16–14
42 (57)
45 (61)
35 (47)
60 (81)
7/16–20
47 (64)
50 (68)
40 (54)
66 (89)
1/2–13
64 (87)
68 (92)
55 (75)
91 (123)
1/2–20
72 (98)
77 (104)
65 (88)
102 (138)
9/16–12
92 (125)
98 (133)
80 (108)
130 (176)
9/16–18
103 (140)
110 (149)
90 (122)
146 (198)
5/8–11
128 (173)
136 (184)
110 (149)
180 (244)
5/8–18
145 (197)
154 (209)
130 (176)
204 (277)
3/4–10
226 (306)
241 (327)
200 (271)
320 (434)
3/4–16
253 (343)
269 (365)
220 (298)
357 (484)
7/8–9
365 (495)
388 (526)
320 (434)
515 (698)
7/8–14
402 (545)
427 (579)
350 (475)
568 (770)
1–8
—
582 (789)
—
—
1–12
—
637 (863)
—
—
1–14
—
652 (884)
—
—
* Freightliner recommends that all plated and unplated fasteners be coated with oil before installation.
† Use these torque values if either the bolt or nut is lubricated or plated (zinc-phosphate conversion-coated, cadmium-plated, or waxed).
Table 3, Torque Values for U.S. Customary Thread Fasteners With Lubricated or Plated Threads
School Bus Chassis Maintenance Manual, October 2005
00/15
00
General Information
Torque Specifications Tables: 00–13
Torque Values for Grade 8 Regular Hex Zinc-Yellow Plated Capscrews and
Cadmium- and Wax-Coated Prevailing Torque Locknuts*
Regular Hex
Thread Diameter-Pitch
Grade 8 or 8.2 Bolt
Grade 8 or C Nut
Torque: lbf·ft (N·m)
f230005
f230004
1/4–20
6 (8)
1/4–28
7 (9)
5/16–18
13 (18)
5/16–24
14 (19)
3/8–16
23 (31)
3/8–24
26 (35)
7/16–14
37 (50)
7/16–20
41 (56)
1/2–13
56 (76)
1/2–20
63 (85)
9/16–12
81 (110)
9/16–18
90 (122)
5/8–11
112 (152)
5/8–18
126 (171)
3/4–10
198 (268)
3/4–16
221 (300)
7/8–9
319 (433)
7/8–14
352 (477)
1–8
479 (649)
1–12
524 (710)
1–14
537 (728)
* Freightliner recommends that all plated and unplated fasteners be coated with oil before installation.
Table 4, Torque Values for Grade 8 Regular Hex Zinc-Yellow Plated Capscrews
and Cadmium- and Wax-Coated Prevailing Torque Locknuts
00/16
School Bus Chassis Maintenance Manual, October 2005
00
General Information
Torque Specifications Tables: 00–13
Torque Values for U.S. Customary Thread Fasteners With Dry (Unlubricated)* Plain (Unplated) Threads†
Regular Hex
Thread
Diameter–Pitch
Grade 5 Bolt
Grade 5 or B
Nut
Torque: lbf·ft (N·m)
Grade 8 or C
Nut
Torque: lbf·ft (N·m)
f230003
f230002
Flanged
Grade 8 or 8.2
Bolt
f230004
Grade 8 or 8.2
Bolt
Grade G Nut
Torque: lbf·ft (N·m)
f230005
f230009
f230008
1/4–20
8 (11)
10 (14)
—
1/4–28
9 (12)
12 (16)
—
5/16–18
15 (20)
22 (30)
22 (30)
5/16–24
17 (23)
25 (34)
—
3/8–16
28 (38)
40 (54)
40 (54)
3/8–24
31 (42)
45 (61)
—
7/16–14
45 (61)
65 (88)
65 (88)
7/16–20
50 (68)
70 (95)
—
1/2–13
70 (95)
95 (129)
95 (129)
1/2–20
75 (102)
110 (149)
—
9/16–12
100 (136)
140 (190)
140 (190)
9/16–18
110 (149)
155 (210)
—
5/8–11
135 (183)
190 (258)
190 (258)
5/8–18
155 (210)
215 (292)
—
3/4–10
240 (325)
340 (461)
340 (461)
3/4–16
270 (366)
380 (515)
—
7/8–9
385 (522)
540 (732)
—
7/8–14
425 (576)
600 (813)
—
1–8
580 (786)
820 (1112)
—
1–12
635 (861)
900 (1220)
—
1–14
650 (881)
915 (1241)
—
* Threads may have residual oil, but will be dry to the touch.
† Male and female threads (bolt and nut) must both be unlubricated and unplated; if either is plated or lubricated, use Table 3. Freightliner recommends that all
plated and unplated fasteners be coated with oil before installation.
Table 5, Torque Values for U.S. Customary Thread Fasteners With Dry (Unlubricated) Plain (Unplated) Threads
School Bus Chassis Maintenance Manual, October 2005
00/17
00
General Information
Torque Specifications Tables: 00–13
Torque Values for Metric Thread Fasteners With Lubricated* or Plated Threads†
Class 8.8 Bolt
Class 8 Nut
Thread
Diameter–Pitch
Torque: lbf·ft (N·m)
8.8
Class 10 Nut
Torque: lbf·ft (N·m)
10.9
8
f230010
Class 10.9 Bolt
f230011
10
f230012
f230013
M6
5 (7)
7 (9)
M8
12 (16)
17 (23)
M8 x 1
13 (18)
18 (24)
M10
24 (33)
34 (46)
M10 x 1.25
27 (37)
38 (52)
M12
42 (57)
60 (81)
M12 x 1.5
43 (58)
62 (84)
M14
66 (89)
95 (129)
M14 x 1.5
72 (98)
103 (140)
M16
103 (140)
148 (201)
M16 x 1.5
110 (149)
157 (213)
M18
147 (199)
203 (275)
M18 x 1.5
165 (224)
229 (310)
M20
208 (282)
288 (390)
M20 x 1.5
213 (313)
320 (434)
M22
283 (384)
392 (531)
M22 x 1.5
315 (427)
431 (584)
M24
360 (488)
498 (675)
M24 x 2
392 (531)
542 (735)
M27
527 (715)
729 (988)
M27 x 2
569 (771)
788 (1068)
M30
715 (969)
990 (1342)
M30 x 2
792 (1074)
1096 (1486)
* Freightliner recommends that all plated and unplated fasteners be coated with oil before installation.
† Use these torque values if either the bolt or nut is lubricated or plated (zinc-phosphate conversion-coated,
cadmium-plated, or waxed).
Table 6, Torque Values for Metric Thread Fasteners With Lubricated or Plated
Threads
00/18
School Bus Chassis Maintenance Manual, October 2005
Engine
01
Index, Alphabetical
Title of Maintenance Operation (MOP)
MOP Number
Engine Drive Belt Inspecting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 01–02
Engine-Support Fasteners Checking (Noise Emission Control). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 01–01
Pacbrake Inspecting and Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 01–03
School Bus Chassis Maintenance Manual, June 2003
01
Engine
01–01 Engine-Support
Fasteners Checking
(Noise Emission
Control)
Check the front and the rear engine-support fasteners for tightness. See Fig. 1. See Group 01 of the
School Bus Chassis Workshop Manual for specifications.
NOTE: At engine overhaul, and whenever the
engine has been removed, inspect the lower
and the upper isolators and replace them if they
are worn. See Fig. 1, Refs. 1 and 6. See Section 01.02 of the School Bus Chassis Workshop
Manual for procedures.
2
6
4
f220047a
1. Lower Isolator
2. Engine Support
Washer
3. Capscrew
4. Hexnut
5. Engine Mount
6. Upper Isolator
Fig. 1, Rear Engine Mount
01–02 Engine Drive Belt
Inspecting
WARNING
The engine and the belt must be cool before you
check the belt. Handling a hot belt can cause personal injury.
School Bus Chassis Maintenance Manual, June 2003
1. Inspect the belt for glazing. See Fig. 2, Ref. A.
Glazing is represented by shiny sidewalls, and is
caused by friction created when a loose belt slips
in the pulleys. It can also be caused by oil or
grease contamination on the pulleys.
3. Check the belt for a jagged or streaked sidewall.
See Fig. 2, Ref. C. Jagged or streaked sidewalls
are the result of foreign objects, such as sand or
gravel in the pulley, or a rough pulley surface.
2
3
10/05/94
Visual Inspection
2. Check the belt for ply separation. See Fig. 2,
Ref. B. Oil, grease, or belt dressing can cause
the belt to fall apart in layers. Repair any oil or
coolant leaks that are affecting the belts before
replacing the drive belts. Do not use belt dressing on any belt.
1
5
Worn or loose drive belts may cause premature
bearing failure or engine overheating. Excessive tension, or too little tension on the belt may result in excessive and premature belt wear. Poly-V belts, or
serpentine belts, are retained by a belt tensioner that
requires no tension adjustment. Replace the engine
drive belt if any conditions described in the visual
description are found. V-belts are installed as individual belts, and as matched sets. When replacing a
matched set of belts, always replace both belts at the
same time. Matched belts must be from the same
manufacturer. To inspect a belt, gently twist the belt
to view the belt sidewalls and bottom. Visually inspect all drive belts for the following conditions, then
perform the belt tension inspection.
4. Check for tensile breaks (breaks in the cord
body). See Fig. 2, Ref. D. Cuts in a belt are usually caused by foreign objects in the pulley, or by
prying or forcing the belt during removal or installation.
5. Check for uneven ribs on serpentine (poly-V)
belts. See Fig. 2, Ref. E. Foreign objects in the
pulley will erode the undercord ribs, causing the
belt to lose its gripping power.
6. Check the drive belts for cracks. See Fig. 2, Ref.
F. Small irregular cracks are usually the signs of
an old belt.
7. Inspect the pulleys for excessive play or wobble.
Excessive play or wobble indicates a failure of
the pulley bearing. Check for belt squealing or
squeaking. Replace the bearings as necessary.
01/1
01
Engine
NOTE: If it is difficult to distinguish the location
of a supposed bearing noise, obtain a stethoscope and place it on the component being
checked, not the pulley, to isolate the area from
outside interference.
8. Inspect all pulleys for foreign objects, oil, or
grease in the grooves.
Belt Tension Inspection
Spring-Tension Type
On belts equipped with a spring tensioner, the belt
tension is automatically adjusted. Check that the tensioner is holding tension on the belt by inserting the
end of a breaker bar in the 1/2-inch square hole on
the forward face of the tensioner, and rotating the
tensioner down, away from the belt. When the
breaker bar is slowly released, the tensioner should
return to its original position.
01–03 Pacbrake Inspecting and
Maintenance
With frequent use, the Pacbrake Exhaust Brake will
operate free of maintenance. However, if the vehicle
is used inconsistently, seasonally, or is exposed to
excess moisture, it will be necessary to perform preventative maintenance using the following steps:
1. With the engine turned off, use Pacbrake Synthetic Lube or Synco Super Lube and spray or
coat a sufficient amount on the restricter air cylinder valve shaft and the attaching locations at
each end of the actuation cylinder. See Fig. 3 for
the exhaust brake lubrication points.
2. Using your hands or a pair of pliers, slide the
valve several times to distribute the lubricant
down the shaft and the attaching locations.
A
D
B
E
C
F
11/21/94
A. Glazing
B. Separating Layers
C. Streaked Sidewalls
f150010a
D. Tensile Break
E. Uneven Ribs
F. Cracks
Fig. 2, Drive Belt Replacement Conditions
01/2
School Bus Chassis Maintenance Manual, June 2003
01
Engine
1
2
03/20/2003
f012035
1. Air Cylinder
2. Pacbrake
Fig. 3, Pacbrake Exhaust Brake Lube Point Locations
NOTE: Operation of the Pacbrake could be affected by starting the engine and idling for short
periods of time. During a cold engine start-up,
moisture occurs in the engine and the exhaust
system that creates a corrosion hazard. The
brake housing may trap water in the valve shaft
bore causing corrosion, resulting in an improper
or non-functioning brake. If it is necessary to
periodically start the engine, reach normal operating temperatures before shutting down the engine.
School Bus Chassis Maintenance Manual, June 2003
01/3
Air Intake
09
Index, Alphabetical
Title of Maintenance Operation (MOP)
MOP Number
Air Cleaner Element Inspecting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 09–01
Air Cleaner Element Replacing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 09–02
School Bus Chassis Maintenance Manual, January 2004
Air Intake
09
09–01 Air Cleaner Element
Inspecting
Inspect the air cleaner element for holes or tears at
the recommended interval. If the air cleaner element
is damaged, replace it. See Group 09 of the School
Bus Chassis Workshop Manual for removal and installation instructions.
09–02 Air Cleaner Element
Replacing
Replace the air cleaner element at the recommended
interval, or when filter restriction reaches 20 to 25
inH 20. See Group 09 of the School Bus Chassis
Workshop Manual for removal and installation instructions. See the School Bus Chassis Operator’s
Manual for specific restriction values for your engine.
School Bus Chassis Maintenance Manual, January 2004
09/1
Alternators and Starters
15
Index, Alphabetical
Title of Maintenance Operation (MOP)
MOP Number
Alternator, Battery, and Starter Checking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15–01
School Bus Chassis Maintenance Manual, January 1999
15
Alternators and Starters
15–01 Alternator, Battery, and
Starter Checking
1. Check the tightness of the alternator bracket fasteners and alternator mounting fasteners; tighten
the fasteners as needed. For torque values, see
Group 15 of the School Bus Chassis Workshop
Manual.
2. Check that all electrical connections at the alternator and starter are clean. Clean and tighten all
charging system electrical connections as
needed.
3. Check the alternator wiring for missing insulation,
kinks, and heat damage. Replace or repair as
needed.
WARNING
Batteries generate explosive gas as a by-product
of their chemical process. Do not smoke when
working around batteries. Put out all flames and
remove any source of sparks or intense heat in
the vicinity of the battery compartment. Make sure
the battery compartment has been completely
vented before disconnecting or connecting the
battery cables.
Battery acid is extremely harmful if splashed in
the eyes or on the skin. Always wear a face shield
and protective clothing when working around batteries.
4.3
Check that foreign objects, such as
stones, bolts, and nuts are removed from
the battery box.
4.4
After cleaning, connect the cables to the
batteries, and tighten them to the torque
specifications listed on the battery, generally 10 to 15 lbf·ft (14 to 20 N·m).
4.5
Spray each connection with dielectric red
enamel and coat the battery terminals
with dielectric grease; see Table 1.
Approved Dielectric Protectants
Protectant Material
Dielectric Grease
Dielectric Red Enamel
Spray-On Application
Dielectric Red Enamel
Brush-On Application
Approved Brand
Lubriplate FLP DS–ES
3M 1602 IVI-Spray Sealer; order
from the PDC
Spray-On B–6–665
Gyptal 1201EW-Low VOC, Red;
order at www.glyptal.com or
1-800-GLP-1201
Table 1, Approved Dielectric Protectants
5. Check the terminals on the battery shut-off
switch and the magnetic switch. Make sure the
terminal connections are clean and tight. Coat
the terminal connections with dielectric red
enamel after cleaning; see Table 1.
4. Inspect the battery cables for wear, and replace
as needed. Clean the cable connector terminals
with a wire brush. See Group 54 of the School
Bus Chassis Workshop Manual for troubleshooting instructions, and for adjustment, repair, or
replacement instructions.
4.1
Clean and tighten the battery ground
cable, terminal, and clamps.
4.2
Inspect the retainer assembly (or battery
hold-downs) and the battery box. Replace
worn or damaged parts. Remove any corrosion with a wire brush, and wash with a
weak solution of baking soda and water.
Rinse with clean water, and dry. Paint the
retainer assembly, if needed, to prevent
rusting.
School Bus Chassis Maintenance Manual, January 1999
15/1
Engine Cooling/Radiator
20
Index, Alphabetical
Title of Maintenance Operation (MOP)
MOP Number
Eaton Viscous Fan Drive Checking (Noise Emission
Radiator Cap Checking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20–01
Radiator Pressure Flushing and Coolant Changing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20–02
School Bus Chassis Maintenance Manual, March 2003
20
Engine Cooling/Radiator
20–01 Radiator Cap Checking
3.3
WARNING
Drain the coolant only when the coolant and engine are cool. Draining it when these are hot could
cause severe personal injury due to scalding.
The radiator cap is the most often ignored part in the
cooling system. If it is suspect, replace it. An inspection means checking the cap with a pressure tester.
A radiator cap in good condition will not open below
9 psi (62 kPa). A visual check is also in order: look
for signs of deterioration of the inner gasket. Also
look for cracks or breaks in the spring retainer in the
cap, and for corrosion or deposits on the spring itself.
If the spring is not in perfect condition, it has probably lost tension; replace it.
20–02 Radiator Pressure
Flushing and Coolant
Changing
NOTE: For additional instructions on cleaning
and flushing the cooling system, see the engine
manufacturer’s maintenance and operation
manual.
CAUTION
When flushing the radiator, do not apply more
than 20 psi (138 kPa) air pressure. Excessive pressure can damage the radiator or heater core.
4. Drain the radiator, and flush the radiator until
clean water flows from the radiator. Remove the
flushing gun.
5. Close the petcock at the bottom of the radiator.
6. Connect the hoses. When you install Breeze
Constant-Torque hose clamps, the clamps must
be tightened to the correct torque. The screw tip
of the clamp must extend about 1/4 inch (6 mm)
from the clamp housing, and the belleville
washer stacks must be collapsed almost flat.
See Fig. 1. You must use a torque wrench to
install these hose clamps correctly. The correct
installation torque for Breeze Constant-Torque
hose clamps is as follows:
For clamps with a 5/16-inch tightening screw
hex: 40 lbf·in (460 N·cm).
For clamps with a 3/8-inch tightening screw hex:
90 lbf·in (1020 N·cm).
WARNING
Drain the coolant only when the coolant and engine are cool. Draining it when these are hot could
cause severe personal injury due to scalding.
Apply no more than 20 psi (138 kPa) air
pressure intermittently to help dislodge
sediment buildup in the core.
A
B
1
1. Drain the radiator.
1.1
Remove the surge tank cap.
1.2
Remove the plug at the bottom of the radiator left side tank to drain the engine
coolant.
2. Disconnect the radiator inlet and outlet hose connections.
3. Flush the radiator.
3.1
3.2
Attach a flushing gun nozzle to the radiator outlet.
Run water in until the radiator is full.
School Bus Chassis Maintenance Manual, March 2003
08/15/94
f200286
A. The screw tip must extend about 1/4 inch (6 mm).
B. The belleville washer stacks must be collapsed
almost flat.
1. Tightening Screw Hex
Fig. 1, Breeze Constant-Torque Hose Clamp
NOTE: All hose clamps will lose torque after
installation due to "compression set." However,
when correctly installed, Breeze Constant-
20/1
20
Engine Cooling/Radiator
Torque clamps will hold enough torque to automatically adjust and keep consistent sealing
pressure. During vehicle operation and shutdown, the screw tip may adjust according to
temperature and pressure changes. The torque
may need to be adjusted for individual applications.
7. Fill the radiator with coolant.
Use a mixture of 50 percent water and 50 percent corrosion-inhibiting antifreeze to protect the
engine to –34°F (–37°C) year round.
See Table 1 for engine cooling system capacity
and Table 2 for approved antifreezes.
Engine Make and Model
Radiator Core and
System Capacity*:
quarts (liters)
Caterpillar CFE Series
otherwise damaged clutch reduces fuel economy,
and could cause serious engine damage.
See Section 20.02 of the School Bus Chassis Workshop Manual for replacement instructions.
1. With the engine shut down, rotate the fan at
least one full turn by hand. It should have a
smooth, steady drag. If it does not, replace the
fan clutch.
2. Check for physical damage to the fan or fan
shroud.
3. At the fan clutch mounting:
3.1
Check for correct drive belt alignment and
tension. For specifications, see Group 01
of the School Bus Chassis Workshop
Manual.
3.2
Check for wear of the fan clutch bearings.
There should be no side-to-side or inand-out movement of the fan clutch.
3.3
Do all of the checks in Section 20.00 of
the School Bus Chassis Workshop
Manual.
28 (26.5)
Cummins B Series and ISB
30.5 (28.9)
Cummins C Series
31.2 (29.5)
Mercedes-Benz 904 Series
29 (27.5)
Mercedes-Benz 906 Series
37.2 (35.2)
* System capacity includes all hoses, fittings, and the heater core.
Table 1, Coolant Capacities
Coolant Manufacturer
Texaco
Coolant Designation*
JC04 Antifreeze
Van Waters and Rogers
Ltd. (Canada)
Diesel Antifreeze No. 6038
* Freightliner-approved antifreeze must meet one of the following conditions: A. Ethylene glycol solution that meets GM 6038–M Engineering Standards. B. Ethylene glycol solution that has less than 0.1% anhydrous sodium metasilicate, and meets either GM 1825–M or GM 1899–M
Engineering Standards.
Table 2, Approved Coolants
20–03 Eaton Viscous Fan Drive
Checking (Noise
Emission Control)
CAUTION
If the fan drive assembly is damaged, replace the
unit as soon as possible. Operating a seized or
20/2
School Bus Chassis Maintenance Manual, March 2003
Clutch
25
Index, Alphabetical
Title of Maintenance Operation (MOP)
MOP Number
Clutch Release Bearing Lubricating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25–01
Clutch Release Cross-Shaft Lubricating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25–02
School Bus Chassis Maintenance Manual, March 2003
25
Clutch
25–01 Clutch Release Bearing
Lubricating
1. Park the vehicle on a level surface. Shut down
the engine, set the parking brake, and chock the
tires.
failure. Do not use chassis grease or multipurpose
lubricants.
4. Remove the chocks.
25–02 Clutch Release CrossShaft Lubricating
2. Remove the clutch inspection plate.
NOTE: Some clutch release bearings are
equipped with a lubrication extension that extends outside of the clutch housing. It is not
necessary to remove the clutch inspection plate
when the lubrication extension is used.
The clutch release cross-shaft is equipped with two
grease fittings in the transmission clutch housing.
See Fig. 2 and Fig. 3. Wipe the dirt from the grease
fittings and lubricate with multipurpose chassis
grease.
3. Wipe the dirt away from the grease fitting. See
Fig. 1. Using a pressure-type grease gun
equipped with high-temperature grease only, lubricate the bearing.
1
2
10/19/93
f250048a
1. Clutch Release Cross-Shaft
2. Grease Fitting
Fig. 2, Cross-Shaft Grease Fitting (left-side)
05/27/93
f250081a
Fig. 1, Clutch Release Bearing and Sleeve Bushing
Grease Fitting (release bearing equipped with a
lubrication extension)
CAUTION
Do not over-lubricate the clutch release bearing.
Over-lubrication could contaminate the clutch internally, causing clutch slippage and premature
School Bus Chassis Maintenance Manual, March 2003
05/27/93
f260146a
Fig. 3, Cross-Shaft Grease Fitting (right-side)
25/1
Transmission
26
Index, Alphabetical
Title of Maintenance Operation (MOP)
MOP Number
Allison Transmission Fluid Level Checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26–05
Allison Transmission Fluid and Filter Changing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26–04
Eaton/Fuller Transmission Oil Changing and Magnetic Plug Cleaning. . . . . . . . . . . . . . . . . . . . . . . . . . . . 26–02
Eaton/Fuller Transmission Oil Level Checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26–01
Transmission Breather Checking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26–03
School Bus Chassis Maintenance Manual, March 2003
26
Transmission
26–01 Eaton/Fuller
Transmission Oil Level
Checking
1. With the transmission at operating temperature,
and the vehicle on a level surface, check the oil
level in the transmission.
1.1
1.2
Clean the area around the fill plug, then
remove the plug from the side of the
case.
Using your finger or a bent pipe cleaner,
see if the oil is level with the fill opening.
See Fig. 1.
case through the main shaft openings. Oil overflow may also drain onto the clutch or clutch
brake, causing additional problems.
IMPORTANT: Do not mix types of oil, because
of possible incompatibility. Do not use oil additives, friction modifiers, or synthetic lubricants.
3. Clean the fill plug, then install it in the transmission. Tighten the plug as follows:
20 to 25 lbf·ft (27 to 34 N·m) for a 3/4-inch plug;
60 to 75 lbf·ft (81 to 102 N·m) for a 1-1/4 inch
plug.
26–02 Eaton/Fuller
Transmission Oil
Changing and Magnetic
Plug Cleaning
Draining
10/05/94
B
A
f260006b
A. Full
B. Low
Fig. 1, Manual Transmission Oil Level Checking
2. If needed, fill the transmission with oil until level
with the lower edge of the fill opening. See
Table 1 for approved lubricants.
Approved Lubricants, Eaton/Fuller Transmissions*
Lubricant Type
Heavy-Duty Engine
Oil
API Service
Classification
SF or CD
Temperature
SAE
Viscosity
Above +10°F (–12°C)
40 or 50
Below +10°F (–12°C)
30
* Do not mix types of oil.
Table 1, Approved Lubricants, Eaton/Fuller
Transmissions
CAUTION
Operating an Eaton/Fuller transmission with the
oil level higher or lower than recommended can
result in transmission damage. Do not overfill the
transmission; overfilling will force oil out of the
School Bus Chassis Maintenance Manual, March 2003
1. Clean the area around the fill plug.
2. Remove the fill plug from the side of the case.
Remove the drain plug(s) from the bottom of the
transmission case.
3. Drain the oil while the transmission is warm.
4. Clean the magnetic plug(s) before installing.
(Use a piece of key stock, or any other convenient steel slug, to short the two magnetic poles
and divert the magnetic field.) Install and tighten
the drain plug(s) 20 lbf·ft (27 N·m).
Filling
1. Add oil until it is level with the lower edge of the
fill opening. See Fig. 1. If the transmission has
two fill openings, add oil to the level of both fill
openings. See Table 1 for approved transmission
lubricants, and Table 2 for lubricant capacities.
CAUTION
Operating an Eaton/Fuller transmission with the
oil level higher or lower than recommended can
result in transmission damage. Do not overfill the
transmission; overfilling will force oil out of the
case through the main shaft openings. Oil over-
26/1
26
Transmission
flow may also drain onto the clutch or clutch
brake, causing additional problems.
IMPORTANT: Do not mix types of oil, because
of possible incompatibility. Do not use oil additives, friction modifiers, or synthetic lubricants.
NOTE: The correct oil level is established by the
fill plug opening.
2. Clean the fill plug, then install it. Tighten the plug
as follows:
20 to 25 lbf·ft (27 to 34 N·m) for a 3/4-inch plug;
60 to 75 lbf·ft (81 to 102 N·m) for a 1-1/4 inch
plug.
Lubricant Capacities, Eaton/Fuller Transmissions
Model
Refill Capacity*:
Quarts (liters)
FS–4205A/B
6.25 (6.0)
FS–5205A/B
5.25 (5.0)
FS–6305A/B
9.5 (9.0)
FS–5306A
9.0 (8.5)
FS–6306A
9.0 (8.5)
* Quantities listed are approximate. With the vehicle in normal operating
position, fill the transmission until the lubricant is level with the bottom of the
fill hole.
Table 2, Lubricant Capacities, Eaton/Fuller
Transmissions
26–03 Transmission Breather
Checking
Transmission housing breathers must remain unobstructed. A plugged breather could result in pressure
build-up, which could cause oil leakage.
If the breather is plugged, clean or replace it. See
Fig. 2. Check more often if the vehicle is operating
under very dusty conditions.
26–04 Allison Transmission
Fluid and Filter
Changing
f260007a
05/27/93
Fig. 2, Transmission Breather (typical)
Freightliner-chassis vehicles. Allison transmissions are received partially filled with TranSynd
synthetic automatic transmission fluid (ATF).
They are then topped-off with a non-TranSynd
ATF. For this reason, Allison’s recommended
extended oil and filter change intervals for
TranSynd-only or for a "mixture" of TranSynd
and non-TranSynd do not apply. To qualify for
the "mixture" intervals, the transmission must be
drained as in a standard fluid change and then
filled with TranSynd. See the Allison Owner’s or
Operator’s Manual for more information.
AT/MT Series
1. Park the vehicle on a level surface and apply the
parking brakes.
2. Run the engine until the transmission fluid
reaches the operating temperature of 160 to
200°F (71 to 93°C). Shift the transmission to
Neutral (N) and shut down the engine.
CAUTION
To prevent dirt from entering the transmission,
use only clean containers and fillers for the transmission fluid. Do not use fillers or containers that
have been used for water or antifreeze. Dirt, water,
or antifreeze could damage the transmission.
IMPORTANT: Extended oil and filter change intervals (as announced by Allison beginning in
2002) do not apply to Allison transmissions in
26/2
School Bus Chassis Maintenance Manual, March 2003
26
Transmission
3. Clean the area around the drain plug. While the
transmission fluid is warm, remove the drain plug
and drain the fluid. Disconnect the fill tube from
the pan.
IMPORTANT: Examine the used transmission
fluid for dirt, coolant or water, and metal particles. If any of these contaminants are present,
a problem may exist within the transmission
system.
4. Support the pan, then remove all of the washerhead screws that attach the pan to the transmission case. Remove the pan, and discard the pan
gasket.
5. Clean the pan with mineral spirits.
6. Remove the washer-head screw that attaches
the internal fluid filter to the filter spacer, then
remove the filter and discard it. See Fig. 3. Remove the fluid intake tube, and then remove the
seal ring from the intake tube, and discard the
seal ring.
7. Remove, clean and install the governor feed line
screen, located in the control valve body. See
Fig. 4.
8. Install a new seal ring on the fluid intake tube.
IMPORTANT: Avoid twisting the intake tube
when installing the internal fluid filter, intake
tube, and seal ring; the seal ring could be
pinched, cut, or deformed. An air-tight seal must
be maintained.
9. Install the intake tube, with the seal ring installed,
in the main housing. Install the internal fluid filter
on the intake tube, making sure that the grommet in the filter fits the intake tube snugly.
10. Install the washer-head screw to retain the fluid
filter, and tighten it 10 to 15 lbf·ft (14 to 20 N·m).
11. Submerge a new pan gasket in transmission fluid
for five minutes. Then place the gasket on the
pan; do not use any substance as a gasket retainer.
IMPORTANT: Do not use gasket-sealing compounds any place inside of the transmission or
where they might be washed into the transmission. Also, nonsoluble vegetable-based cooking
compounds or fibrous greases must not be used
inside the transmission.
12. Install the pan and gasket.
12.1
Guide the pan and gasket carefully into
place. Guard against dirt or foreign material entering the pan. Retain the pan with
four 5/16–18 washer-head screws, installed by hand in the corners of the pan.
12.2
Install the remaining washer-head screws
by hand, carefully threading each through
the gasket and into the transmission. Bottom all of the screws before tightening
any of them.
12.3
Tighten all of the screws evenly 10 to 15
lbf·ft (14 to 20 N·m). Check the gasket fit
while the screws are being tightened.
6
5
1
2
3
4
f260133a
10/05/94
1.
2.
3.
4.
Fluid Intake Tube
Filter Spacer
Internal Fluid Filter
Washer-Head Screw
5. Governor Pressure
Tube
6. Governor Feed Tube
Fig. 3, Allison AT Series Transmission Filter
IMPORTANT: The pan bolts must maintain a
minimum torque of 60 lbf·in (680 N·cm) after
the pan gasket has taken a set.
13. Install the fill tube at the side of the pan. Tighten
the tube fitting 90 to 100 lbf·ft (122 to 136 N·m).
School Bus Chassis Maintenance Manual, March 2003
26/3
26
Transmission
1
8
2
3
4
9
10
7
5
6
f260132a
10/05/94
1.
2.
3.
4.
5.
6.
Fluid Intake Tube
Detent Spring
Detent-Spring 1-3/4" Bolt
Filter Spacer
2-1/4" Bolt (16 qty.)
First/Reverse Clutch Feed-Tube 3" Bolt (2 qty.,
behind)
7.
8.
9.
10.
First/Reverse Clutch Feed Tube
Governor Screen (in control valve body)
Governor Pressure Tube
Governor Feed Tube
Fig. 4, Allison AT Series Transmission Governor
14. Install the drain plug and gasket, and tighten the
plug 15 to 20 lbf·ft (20 to 27 N·m).
15. Replace the external (auxiliary) fluid filter.
16. Clean the area around the fill tube and remove
the dipstick. Using a clean funnel in the fill tube,
add transmission fluid. See Table 3 for approved
automatic transmission lubricants, and Table 4
for AT/MT series lubricant capacities.
17. Check and adjust the fluid level using the procedure under "Allison Transmission Fluid Level
Checking."
26/4
Approved Lubricants, Allison Transmissions*
Lubricant Type
Temperature
Dexron III ATF
–25° to +120°F (–32° to +48°C)
TranSynd
Synthetic ATF
–25° to +120°F (–32° to +48°C)
* Factory filled with Dexron III. For off-highway operation or where ambient
temperature is consistently above +86°F (+30°C) or below –25°F (–32°C),
see the manufacturer’s fluid recommendations.
Table 3, Approved Lubricants, Allison Transmissions
School Bus Chassis Maintenance Manual, March 2003
26
Transmission
Lubricant Capacities, Allison AT/MT/MD Series
Transmissions
Model
Refill Capacity*:
Quarts (liters)
AT–542
16.0 (15.1)
AT–545
21.0 (19.9)
MT–643
19.0 (18.0)
MD–3060P
MD–3060PR
17.5 (16.5)
* Quantities listed are approximate. Add the recommended amount of fluid
as listed under refill capacity, then perform a "hot check" and add fluid as
needed. Do not overfill.
Table 4, Lubricant Capacities, Allison AT/MT/MD
Series Transmissions
MD Series
1. See Fig. 5. Park the vehicle on a level surface
and set the parking brake.
1
2
2. Run the engine until the transmission fluid
reaches an operating temperature of 160 to
200°F (71 to 93°C). Shift the transmission to
Neutral (N) and shut down the engine.
3
4
5
CAUTION
To prevent dirt from entering the transmission,
use only clean containers and fillers for the transmission fluid. Do not use fillers or containers that
have been used for water or antifreeze. Dirt, water,
or antifreeze could damage the transmission.
3. Clean the area around the drain plug. While the
transmission fluid is warm, remove the drain
plug, and drain the fluid.
IMPORTANT: Examine the used transmission
fluid for dirt, coolant or water, and metal particles. If any of these contaminants are present,
a problem within the transmission system may
exist.
6
06/04/99
1.
2.
3.
4.
7
Drain Plug O-Ring
Drain Plug
Filter
Filter O-Ring
f260130a
5. Seal
6. Filter Cover
7. M10 Bolt
Fig. 5, Allison MD Series Transmission
stall and tighten the bolts 38 to 45 lbf·ft (52 to 61
N·m). Install and tighten the drain plug 18 to 24
lbf·ft (24 to 33 N·m).
4. Remove the bolts from each filter cover at the
bottom of the transmission control module. Remove the filter covers, O-rings, seals, and the
two cartridge-type filters.
6. Clean the area around the fill tube and remove
the dipstick. Using a clean funnel in the fill tube,
add transmission fluid. See Table 3 for approved
transmission lubricants, and see Table 4 for MD
series lubricant capacities.
5. Coat the O-rings lightly with clean transmission
fluid. Place the O-rings, seals, and filters on the
filter covers. Push each cover assembly into the
bottom of the transmission to seat the seals. In-
7. Check and adjust the fluid level using the procedures under "Allison Transmission Fluid Level
Checking."
School Bus Chassis Maintenance Manual, March 2003
26/5
26
Transmission
2000/2400 Series
1. Park the vehicle on a level surface and set the
parking brake.
NOTE: For 2000/2400 series transmissions with
non-TranSynd ATF, change oil and filters at
50,000 miles (80 000 km) or 24 months, whichever comes first.
2. Operate the vehicle until the transmission
reaches normal operating temperature: 160 to
200°F (71 to 93°C).
IMPORTANT: When draining transmission fluid,
check for evidence of dirt or water contamination. A small amount of condensation will appear
in the fluid during operation. See Fig. 6. Water
contamination is normally characterized as a
milky discoloration of the transmission fluid. Obvious contamination of the transmission fluid
indicates a leak between the water and fluid areas of the transmission cooler. Inspect and
pressure-test the cooler to confirm the leak; replace leaking transmission coolers.
3. Clean the area around the drain plug and the
transmission fluid pan. Place a drain pan under
the transmission and remove the drain plug. Examine the fluid as it drains.
4. Place a drain pan under the external filter. Remove the external filter with a strap type filter
wrench by turning it counterclockwise.
5. Remove the magnet from the filter attachment
tube or the top of the filter element. Clean any
debris from the magnet.
NOTE: Report to your maintenance personnel
any debris attached to the magnet larger than
dust.
6. Reinstall the magnet on the filter attachment
tube.
7. Lubricate the gasket on the new filter with clean
transmission fluid.
8. Install, by hand, the filter until the gasket on the
filter touches the converter housing or cooler
manifold.
9. Turn the filter ONE FULL TURN ONLY after the
gasket contacts the transmission.
10. Replace the drain plug O-ring, and install the
drain plug. Tighten the drain plug 22 to 30 lbf·ft
(30 to 40 N·m).
1
2
03/31/2000
f261061
1. Magnet
2. External Filter
Fig. 6, Allison 2000/2400 Series Transmission External
Filter
CAUTION
To prevent dirt from entering the transmission,
use only clean containers and fillers for the transmission fluid. Do not use fillers or containers that
have been used for water or antifreeze. Dirt, water,
or antifreeze could damage the transmission.
26/6
11. Refill the transmission with fresh transmission
fluid. See Table 3 for approved automatic transmission lubricants.
12. Check the fluid level. See Table 5 for 2000/2400
series lubricant capacities.
Check and adjust the fluid level using the procedures under "Allison Transmission Fluid Level
Checking."
Lubricant Capacities, Allison 2000/2400 Series
Transmissions
Model
Refill Capacity*:
quarts (liters)
2000/2400 Standard Sump
10.6 (10)
School Bus Chassis Maintenance Manual, March 2003
26
Transmission
Lubricant Capacities, Allison 2000/2400 Series
Transmissions
Model
2000/2400 Shallow Sump
Refill Capacity*:
quarts (liters)
7.4 (7)
* Quantities listed are approximate. Add the recommended amount of fluid
as listed under refill capacity, then perform a "hot check" and add fluid as
needed. Do not overfill.
Table 5, Lubricant Capacities, Allison 2000/2400
Series Transmissions
3. Wipe the dipstick clean and check the fluid level.
A safe operating level is any level within the HOT
RUN (upper) band on the dipstick. See Fig. 7.
4. If the fluid is not within this range, add or drain
fluid as needed to bring the level to the top of
the HOT RUN band. See Table 3 for approved
automatic transmission lubricants, and Table 4
and Table 5 for automatic transmission lubricant
capacities.
26–05 Allison Transmission
Fluid Level Checking
Cold Check
IMPORTANT: The only purpose of the Cold
Check is to determine if the transmission has
enough fluid to be safely operated until a Hot
Check can be made.
1. A cold check may be made when the sump temperature is 60 to 104°F (15 to 40°C).
2. Run the engine for at least one minute to clear
the fluid system of air.
3. With the engine running, wipe the dipstick clean
and check the fluid level. Any level within the
COLD RUN (lower) band is satisfactory for operating the vehicle. If the level is not within the
COLD RUN band, add or drain fluid until it
reaches the middle of the COLD RUN band. See
Fig. 7.
4. Perform a hot check at the first opportunity after
normal operating temperature, 160 to 200°F (71
to 93°C), is reached.
Hot Check
1. Operate the transmission in a Drive (D) range
until normal operating temperature, 160 to 200°F
(71 to 93°C), is reached.
NOTE: The fluid must be warm to ensure an
accurate check. The fluid level rises as temperature increases.
2. Park the vehicle. Shift to Neutral (N) and set the
parking brake. Let the engine run at idle.
School Bus Chassis Maintenance Manual, March 2003
26/7
26
REF
FILL
Transmission
COLD
RUN
HOT
RUN
CHECK IN NEUTRAL @ IDLE USE DEXRON R OIL
f011103
08/23/96
Fig. 7, Dipstick Markings
26/8
School Bus Chassis Maintenance Manual, March 2003
Frame
31
Index, Alphabetical
Title of Maintenance Operation (MOP)
MOP Number
Frame Fastener Torque Checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31–01
School Bus Chassis Maintenance Manual, March 2003
31
Frame
31–01 Frame Fastener Torque
Checking
Because of "bedding in" (or seating), the frame fasteners must be torqued at the recommended intervals. These intervals apply to new vehicles, and to
frame fasteners that have been removed and installed again.
CAUTION
Make sure frame fasteners are properly tightened.
Continued vehicle operation with loose fasteners
could result in bracket or frame damage.
Typical frame fastener applications include suspension brackets, fuel tank, exhaust and engine supports, frame crossmembers, and gussets.
NOTE: This operation is not intended to be a
bolt-by-bolt check of the entire chassis. Do a
hand check of the typical frame fasteners. If any
fasteners are found loose, tighten them to the
correct torque value.
See Group 00 of the School Bus Chassis Workshop
Manual for additional information on fasteners and
torque values.
School Bus Chassis Maintenance Manual, March 2003
31/1
Suspension
32
Index, Alphabetical
Title of Maintenance Operation (MOP)
MOP Number
Component Clearance Checking, Freightliner AirLiner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32–06
Component Inspecting and Operation Checking, Freightliner AirLiner . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32–07
Control Rod Checking, Freightliner AirLiner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32–11
Fastener Torque Checking, Freightliner AirLiner. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32–05
Fastener Torque Checking, Hendrickson . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32–12
Radius Rod Bushing Checking, Hendrickson. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32–10
Shock Absorber Checking, Freightliner Spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32–09
Spring Bracket Fastener Torque Checking, Freightliner Spring (Rear). . . . . . . . . . . . . . . . . . . . . . . . . . . . 32–04
Suspension Inspecting, Freightliner Spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32–01
Suspension Lubricating, Freightliner Spring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32–02
U-Bolt Torque Checking, Freightliner AirLiner. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32–08
U-Bolt Torque Checking, Freightliner Spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32–03
School Bus Chassis Maintenance Manual, March 2003
32
Suspension
32–01 Suspension Inspecting,
Freightliner Spring
32–02 Suspension Lubricating,
Freightliner Spring
Front and Rear Suspension Spring
Assemblies
Front Suspension
Inspect the front and rear suspension spring assemblies for pitted, cracked, broken, or abnormally bent
leaves and extreme rust. If any of these conditions
exist, replace the spring assembly. See Group 32 of
the School Bus Chassis Workshop Manual for instructions.
WARNING
Do not replace individual leaves of a damaged leaf
spring assembly; replace the complete spring assembly. Visible damage (cracks or breaks) to one
leaf causes hidden damage to other leaves. Replacement of only the visibly damaged part(s) is
no assurance that the spring is safe. On front
spring assemblies if cracks or breaks exist in the
two top leaves, a loss of vehicle control could occur. Failure to replace a damaged spring assembly
could cause an accident resulting in property
damage, serious personal injury or death.
Wipe all dirt from the grease fittings at the forward
spring pin and the spring shackle pins; then apply
multipurpose chassis grease with a pressure gun until the old grease is forced out.
Rear Suspension
Single Axle
Lubricate the spring pin by applying multipurpose
chassis grease at the grease fitting. See Fig. 1. Lubricate with a grease gun until grease appears at the
base of the fitting.
IMPORTANT: On multi-leaf suspensions, closely
inspect each component of the leaf spring assemblies, including the brackets, U-bolts, and
related parts.
Rear Suspension Spring Brackets
Inspect the forward and rear spring brackets and the
wear pads, for wear, cracks, and other damage. If
any of these conditions exist, replace the damaged
bracket(s) and wear pad(s). See Group 32 of the
School Bus Chassis Workshop Manual for instructions.
WARNING
Replace worn, cracked, or damaged spring brackets. Failure to do so could result in bracket breakage, possibly leading to loss of vehicle control
and resulting in personal injury or property damage.
10/05/94
f320268a
Fig. 1, Forward Spring Bracket Spring Pin Grease
Fitting
32–03 U-Bolt Torque Checking,
Freightliner Spring
Check the U-bolt torque of both the front and rear
axles.
CAUTION
Failure to retorque the U-bolt nuts could result in
spring breakage and abnormal tire wear.
School Bus Chassis Maintenance Manual, March 2003
32/1
32
Suspension
In a diagonal pattern, tighten all 5/8–18 U-bolt nuts
205 lbf·ft (278 N·m); tighten all 3/4–16 U-bolt nuts
300 lbf·ft (407 N·m); and tighten all 7/8–14 U-bolt
nuts 460 lbf·f (624 N·m).
32–04 Spring Bracket Fastener
Torque Checking,
Freightliner Spring
(Rear)
CAUTION
Continued use with loose fasteners could result in
bracket and frame damage.
Torque the fasteners that attach the forward and rear
spring brackets and equalizer brackets to the frame
rail. Tighten 1/2–13 locknuts with hardened washers
85 lbf·ft (115 N·m). Tighten 5/8–11 locknuts with
hardened washers 170 lbf·ft (230 N·m). Tighten
3/4–10 locknuts with hardened washers 305 lbf·ft
(415 N·m).
See Group 00 for other frame fastener torques.
32–05 Fastener Torque
Checking, Freightliner
AirLiner
Tighten all suspension fasteners to the torque values
in Table 1. Also, tighten all suspension air line fittings
and air lines.
Size
Torque:
lbf·ft (N·m)
Leveling Valve Adjustment Nut
1/4–20
5 (7)
Leveling Valve Mounting Bolt
Nuts
5/16–18
14 (19)
Air Spring Upper Mounting
Locknuts
3/4–16
45 (61)
1/2–13
23 (31)
Air Spring Lower Mounting
Locknuts
1/2–13
55 (75)
Leaf Spring Mounting Eye Bolt
Locknuts
3/4–16
270 (365)
Shock Absorber Upper Bracket
Mounting Locknuts
5/8–11
125 (170)
Description
32/2
Size
Torque:
lbf·ft (N·m)
Air Spring Upper Mounting
Bracket
5/8–11
125 (170)
Spring Hanger Mounting
Locknuts
3/4–10
210 (285)
Lateral Control Rod Nut
5/8–11
136 (185)
Description
Table 1, Torque Values for Freightliner AirLiner
Suspensions
32–06 Component Clearance
Checking, Freightliner
AirLiner
Check that the air line support brackets are positioned so that air lines do not rub against anything.
Reposition any configurations that could contact and
result in friction and wear. There must be at least 1
inch (25 mm) clearance around the rubber air spring
when inflated. If the clearance is less than 1 inch (25
mm), relocate the obstructing parts.
CAUTION
Failure to relocate obstructing parts could result
in damage to the air spring.
32–07 Component Inspecting
and Operation Checking,
Freightliner AirLiner
WARNING
Inspect the components and check their operation
as described below. Failure to perform these inspections and checks could result in separation of
worn suspension components and loss of vehicle
control, possibly causing personal injury and
property damage.
1. Chock the front tires. Raise the rear of the vehicle so that the tires just clear the ground and
so that the suspension is fully extended. Place
safety stands under the vehicle frame.
2. Squeeze all air springs to check for complete
deflation. If any air springs remain partially or
School Bus Chassis Maintenance Manual, March 2003
32
Suspension
fully inflated, see Group 32 of the School Bus
Chassis Workshop Manual.
3. Inspect each air spring for wear at the connection to the pedestal. Replace any worn air
springs; for instructions, see Group 32 of the
School Bus Chassis Workshop Manual.
4. Check the axle connection welds (beam-seat to
equalizing-beam) and axle-adapter to axle for
cracks. If welds are cracked, grind them out and
reweld the parts.
32–09 Shock Absorber
Checking, Freightliner
Spring
Make sure that the shock absorber brackets are
tight, and that the shock absorber is not striking or
rubbing on the frame or some other part of the chassis. See Fig. 2. Check the rubber mounting bushings
and replace if worn. Inspect the shock absorber for
oil leakage.
5. Move the axle up and down while checking for
signs of looseness due to worn parts at the front
pivot connections. Replace any worn parts by
following the procedures in Group 32 of the
School Bus Chassis Workshop Manual.
1
6. Inspect the shock absorbers for oil leaks and
worn rubber bushings. Replace the shock absorbers and/or rubber bushings if wear or damage is noted. For instructions, see Group 32 of
the School Bus Chassis Workshop Manual.
2
7. Remove the safety stands and lower the rear of
the vehicle to the ground. Run the engine until
air pressure of at least 100 psi (689 kPa) is
maintained throughout the system.
8. Check that all air springs are inflated. If the air
springs do not inflate, see Group 32 of the
School Bus Chassis Workshop Manual for possible causes and corrections.
32–08 U-Bolt Torque Checking,
Freightliner AirLiner
In a diagonal pattern, tighten all 5/8–18 U-bolt nuts
205 lbf·ft (278 N·m); tighten all 3/4–16 U-bolt nuts
300 lbf·ft (407 N·m); and tighten all 7/8–14 U-bolt
nuts 460 lbf·ft (624 N·m).
CAUTION
Failure to retorque the U-bolt nuts could result in
spring breakage and abnormal tire wear.
3
10/05/94
f320267a
1. Upper Mounting Bracket
2. Shock Absorber
3. Lower Mounting Bracket
Fig. 2, Shock Absorber Installation (front suspension
shown)
If the shock absorber is worn or damaged, replace it
with a new one.
32–10 Radius Rod Bushing
Checking, Hendrickson
1. Without detaching the radius rods, attempt to
move (by hand) each of the radius-rod ends up,
down, in, and out. If there is any movement, replace the radius rod.
School Bus Chassis Maintenance Manual, March 2003
32/3
32
Suspension
2. Inspect the rubber bushing ends. Replace the
radius rod if there are gaps between the rubber
bushing and the pin or the outer steel sleeve, if
either bushing end contacts a radius rod pin
mounting bolt, if there are cracks in the bushing,
or if part of the rubber bushing extends beyond
the outside circumference of the outer bushing
sleeve.
32–11 Control Rod Checking,
Freightliner AirLiner
1. Without disconnecting the control rods, attempt
to move (by hand) each of the control rod ends
up, down, in, and out. If there is any movement,
examine the control rods for wear or damage.
Replace if necessary.
2. Inspect the rubber bushings for cracks or cuts.
32–12 Fastener Torque
Checking, Hendrickson
Tighten the suspension fasteners to the torque values given in Table 2.
All Hendrickson beam end fasteners must maintain
their torque values to firmly clamp the rubber bushing
inner metal tubes to the beam hanger legs.
WARNING
Insufficient beam end fastener torque could cause
the beam to separate from the axle. This will
cause loss of vehicle control resulting in property
damage, serious personal injury or death.
Tighten the nut to the torque value in Table 2. Do not
over-torque. See Fig. 3.
3. Check for any shifting of the bar pin.
4. Check for cracks in the metal components and
welds.
IMPORTANT: Be sure to follow the maintenance
schedule for checking the torque of the control
rod fasteners; see Table 1 for control rod torque
values.
Description
Size
Torque: lbf·ft (N·m)
U-Bolt Locknut
7/8–14
425 (576)
Torque Rod Bar Pin Locknut
5/8–11
180 (244)
Spring Seat Stud
5/8–11
65 (88)
Rebound Bolt Locknut
1/2–13
60 (81)
Shock Absorber Locknut, Upper
1/2–13
60 (81)
Shock Absorber Locknut, Lower
3/4–10
60 (81)
Cross Channel to Main Support Member Locknut
3/4–10
290 (393)
Air Spring to Frame Hanger Locknut
1/2–13
25 (34)
Air Spring to Cross Channel Locknut
1/2–13
25 (34)
Transverse Rod Locknut
1-1/4–12
200 (271)
Extension Arm Jam Nut
5/16–24
125 (169)
Extension Arm Locknut
5/16–24
125 (169)
Table 2, Torque Values for Hendrickson Suspension
32/4
School Bus Chassis Maintenance Manual, March 2003
32
Suspension
5
2
1
2
3
4
f320110a
05/27/93
NOTE: Do not use the three-piece adapter without the
intermediate tube.
1. Nut
2. Adapter
3. Intermediate Tube
4. Inner Metal of Beam
End Bushing
5. Beam Hanger
Fig. 3, Three-Piece Adapter-Type Beam End Connection
School Bus Chassis Maintenance Manual, March 2003
32/5
Front Axle
33
Index, Alphabetical
Title of Maintenance Operation (MOP)
MOP Number
All-Axle Alignment Checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33–04
Knuckle Pin Lubricating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33–01
Oil-Filled Hubs Oil Changing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33–06
Oil-Filled Hubs Oil Level Checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33–05
Tie-Rod End Inspecting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33–03
Tie-Rod End Lubricating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33–02
Wheel Bearing Removing, Cleaning, Checking, Repacking, and Adjusting . . . . . . . . . . . . . . . . . . . . . . . . 33–07
School Bus Chassis Maintenance Manual, July 2003
33
Front Axle
33–01 Knuckle Pin Lubricating
1
Hold a pressure gun on each fitting until fresh grease
appears. See Fig. 1 or Fig. 2. This will ensure that
all of the old contaminated grease has been forced
out. It is not necessary to exceed 4000 psi (27 560
kPa). The best distribution of new lubricant and the
best purging of old lubricant occurs when about 4000
psi (27 560 kPa) pressure is applied at the grease
gun nozzle. Using a 40 to 1 booster, the air should
be limited to 100 psi (689 kPa); using a 50 to 1
booster, the air should be limited to 80 psi (551 kPa).
Higher or lower pressures are not recommended.
2
1
1
06/13/2003
f330213
1. Grease Fitting
2. Steering Knuckle
Fig. 2, ABP Axle Grease Fittings
or needle bearings until new grease is seen at the
seal on the bushing or needle bearing opposite the
fittings.
A
1
10/20/93
f320032a
Pump lubricant into each grease fitting until fresh grease
comes out at A.
1. Grease Fitting
Fig. 1, Meritor Axle Grease Fittings
When lubricating Meritor knuckle pin bushings or Alliance Brand Product (ABP) axle needle bearings for
Initial Maintenance, raise the front axle until the front
tires are off of the ground. Wipe the lube fittings
clean, and slowly feed (for Meritor axles) multipurpose chassis grease (NLGI grade 1 or 2) into each
bushing area, or (for ABP axles), lithium 12-hydroxy
stearate (with molybdenum disulfide) WL grade 2
grease into each needle bearing area, while turning
the wheels from extreme right to left and back again
(lock-to-lock). This will eliminate small air pockets
and improve grease distribution.
Lower the front axle so that the tires are on the
ground, and regrease both top and bottom bushings
School Bus Chassis Maintenance Manual, July 2003
NOTE: The grease seal will accept the grease
pressure without damaging the seal, and is designed to have grease pumped out through it
during lubrication. Even if grease leaks out
around the top or bottom plate, continue pumping until new grease is seen at the seal on the
bushing or needle bearing opposite the grease
fitting.
When lubricating knuckle pin bushings or needle
bearings at M1 through M3, do not raise the front
axle. Wipe the lube fittings clean, and (for Meritor
axles) apply multipurpose chassis grease, or (for
ABP axles), lithium 12-hydroxy stearate (with molybdenum disulfide) WL grade 2 grease, until new
grease is seen at the grease seal on the bushing or
needle bearing opposite the fittings.
33–02 Tie-Rod End Lubricating
Wipe the tie-rod end grease fittings clean, then (for
Meritor axles) pump multipurpose chassis grease
(NLGI grade 1 or 2), or (for ABP axles), lithium 12hydroxy stearate (with molybdenum disulfide) WL
grade 2 grease, to the tie-rod ends until all used
grease is forced out and new grease appears at the
ball stud neck.
33/1
33
Front Axle
33–03 Tie-Rod End Inspecting
IMPORTANT: DOT roadside tie-rod assembly
replacement criteria specifies that if tie-rod endplay is 1/8 inch (3 mm) or greater, measured on
the road, the vehicle must be taken out of service immediately. If less than 1/8 inch (3 mm),
the vehicle does not have to be taken out of
service but a major out-of-service inspection
and maintenance must be scheduled as soon
as possible.
into the cross-tube split for adequate
clamping. See Fig. 4. Replace the parts if
this cannot be done. For instructions, see
the axle manufacturer’s service manual.
2.2
Check the tie-rod end nut and clamp nut
torques. For Meritor axles, tighten the tierod end nut 100 lbf·ft (136 N·m), and
tighten the clamp nut 40 to 55 lbf·ft (54 to
75 N·m). For ABP axles, see Table 1 for
tie-rod end nut torque specifications and
Table 2 for tie-rod end clamp nut torque
specifications.
1. Check the tie-rod ends for looseness.
1.1
Park the vehicle so that the front wheels
are in the "straight ahead" position.
1.2
Chock the front and rear tires.
1.3
Remove dirt and grease from the seals or
boots on the tie-rod ends. Visually inspect
the tie-rod ends. Replace the tie-rod ends
if the seals or boots are cracked, worn, or
damaged.
CAUTION
Check the tie-rod endplay by hand. Do not use a
pry bar. If a pry bar is used, the dial indicator will
not read correctly.
NOTE: for accurate readings, use a dial indicator with a "contour-type" base.
1.4
Position the dial indicator so that the base
of the indicator is on the bottom of the
tie-rod arm. Place the tip of the indicator
on the bottom of the tie-rod end at the
center of the ball stud on the surface that
is most flat, as shown in Fig. 3.
1.5
Set the dial indicator to zero.
1.6
By hand, move the tie-rod end and the
cross tube assembly up and down. If the
dial indicator reads more than 0.060 inch
(1.52 mm), replace the tie-rod end.
1.7
Install the dial indicator as described
above, and repeat this procedure on the
opposite tie-rod end.
2. Inspect the tie-rod ends.
2.1
33/2
The threaded portion of the tie-rod end
assembly must be inserted all the way
ABP Axle Tie-Rod End Nut
Thread
Torque: lbf·ft (N·m)
5/8–16
60 to 115 (81 to 156)
5/8–18
60 to 115 (81 to 156)
3/4–16
90 to 170 (122 to 230)
7/8–14
160 to 300 (217 to 407)
Table 1, ABP Axle Tie-Rod End Nut
ABP Axle Tie-Rod End Clamp Nut
Thread
Torque: lbf·ft (N·m)
1/2–13
35 to 45 (47 to 61)
5/8–11
40 to 60 (54 to 81)
5/8–18
50 to 64 (73 to 87)
3/4–10
155 to 175 (210 to 237)
Table 2, ABP Axle Tie-Rod End Clamp Nut
33–04 All-Axle Alignment
Checking
Drive Axle Alignment Checking
Check the axle alignment, parallelism, and thrust
angle measurements for the rear drive axles. Use the
applicable procedure and specifications in Group 35
of the School Bus Chassis Workshop Manual.
Wheel Alignment Checking, Front
Axle
See Group 33 of the School Bus Chassis Workshop
Manual for wheel alignment procedures.
School Bus Chassis Maintenance Manual, July 2003
33
Front Axle
33–05 Oil-Filled Hubs Oil Level
Checking
1
WARNING
2
Be careful not to overfill the hubs. Overfilling may
cause oil to be forced out of the hubs and to contaminate the brake linings and other brake components. This could result in loss of vehicle control
and lead to personal injury and property damage.
f330131
07/18/96
NOTE: If the reading is more than 0.060 inch (1.52 mm)
when moving the tie-rod end and cross tube assembly
up and down, replace the tie-rod end.
1. With the vehicle on a level surface, rotate the
front wheels and allow the oil in the hubs to
settle.
2. Chock the tires.
1. Tie-Rod End
2. Dial Indicator with "Contour-Type" Base
Fig. 3, Measuring Tie-Rod End Looseness
IMPORTANT: The oil level should be at, or no
more than 1/4 inch (6 mm) above, the level indicators on the hub caps.
3. If necessary, remove the filler caps (in the ends
of the hub caps) and add enough oil (80/90 hypoid gear oil) to bring the oil to the proper level.
OK
4. Rotate the wheels, allow the oil to settle, and
check the levels again.
5. Install the filler caps securely.
6. Remove the chocks from the tires.
1
33–06 Oil-Filled Hubs Oil
Changing
OK
WARNING
f320033a
10/13/2005
IMPORTANT: The tie-rod end threads must be visible
throughout the entire length of the split.
NOTE: Pinch bolt not shown to provide clarity.
1. Cross-Tube Split
Fig. 4, Tie-Rod End Adjustment
Be careful not to overfill the hubs. Overfilling may
cause oil to be forced out of the hubs and to contaminate the brake linings and other brake components. This could result in loss of vehicle control
and lead to personal injury and property damage.
1. With the vehicle on a level surface, rotate the
front wheels so that the front hub drain plugs are
positioned downward.
2. Chock the tires.
3. Place suitable containers under the hubs, remove the filler caps (in the ends of the hub caps)
and the drain plugs, and allow the hubs to drain
completely.
School Bus Chassis Maintenance Manual, July 2003
33/3
33
Front Axle
4. Install the drain plugs and tighten securely.
5. Add approximately 1 to 1-1/2 pints (0.5 to 0.7 L)
of oil (80/90 hypoid gear oil) to each hub.
6. Rotate the wheels, allow the oil to settle, and
check the levels.
IMPORTANT: Fill the hubs to the level indicators
on the hub caps, or to no more than 1/4 inch (6
mm) above the indicators.
7. Install the filler caps securely.
8. Remove the chocks from the tires.
33–07 Wheel Bearing
Removing, Cleaning,
Checking, Repacking,
and Adjusting
See Group 33 of the School Bus Chassis Workshop
Manual for wheel bearing service procedures.
33/4
School Bus Chassis Maintenance Manual, July 2003
Rear Axle
35
Index, Alphabetical
Title of Maintenance Operation (MOP)
MOP Number
Axle Breather Checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35–03
Axle Lubricant Changing and Magnetic Plug Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35–02
Axle Lubricant Level Checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35–01
School Bus Chassis Maintenance Manual, July 2003
35
Rear Axle
35–01 Axle Lubricant Level
Checking
CAUTION
Failure to keep the rear axle filled to the proper
level with the recommended lubricant can result in
rear axle damage.
NOTE: If the vehicle is exposed to water deep
enough to cover the hubs, disassemble and inspect them for water damage and/or contamination. See Group 35 of the School Bus Chassis
Workshop Manual for instructions.
1. Clean the oil fill hole plug, located in the carrier
or the side of the axle housing, and the area surrounding it. Remove the plug.
NOTE: Some Meritor axles have a small tapped
and plugged hole located near and below the
housing oil fill hole. This smaller hole is for the
lubricant temperature sensor only, and must not
be used as a fill or level hole.
2. With the vehicle on level ground, lubricant must
be level with the bottom of the oil fill hole.
If low, add lubricant. See Table 1 for Alliance
Brand Product (ABP) axle lubricant capacities.
See Table 2 for Meritor axle lubricant capacities
and see Table 3 for approved Meritor axle lubricants.
Recommended
Lubricant Type
Hypoid Gear Oil
API Service
Classification GL–5
Synthetic Gear Oil
3. On ABP axles, install the fill hole plug, and
tighten it securely.
4. On Meritor axles, install the fill hole plug, and
tighten 35 lbf·ft (47 N·m).
ABP Drive Axle Lubricant Capacities
Differential/Hubs
Capacity: quarts (liters)
Differential Only
5.8 (5.5)
Differential and Hubs
7.4 (7.0)
Table 1, ABP Drive Axle Lubricant Capacities
Meritor Drive Axle Lubricant Capacities (single axle)*
Axle Model
Capacity: pints (liters)†
RS–13–120
16 (7.6)
RS–15–120
16 (7.6)
RS–17–145
33.6 (15.9)
RS–19–145
34.4 (16.3)
RS–21–145
32 (15.1)
RS–23–160
42 (19.9)
RS–26–180
46.6 (22)
* Single drive axles equipped with traction equalizers may require a "friction
modifier" to correct a slip-stick condition, as described in the vehicle driver’s
manual. Meritor’s experience shows that the following additives perform adequately: Add Elco No. 2 Friction Modifier (1 ounce [30 ml] of additive for
each 1 pint [0.5 liter] of lube capacity) or Lubrizol No. 797 or 762 (one
ounce [30 mL] of additive for each 1 pint [0.5 liter] of lube capacity).
† Quantities listed are approximate and include 1 pint (0.5 liter) for each
wheel end and with the drive pinion at 3 degrees.
Table 2, Meritor Drive Axle Lubricant Capacities
Ambient Temperature
Lubricant SAE
Viscosity Grade
Meritor
Specification
+10°F (–12.2°C) and up*
85W–140
0–76–A
–15°F (–26.1°C) and up*
80W–140
0–76–B
–15°F (–26.1°C) and up*
80W–90
0–76–D
–40°F (–40°C) and up*
75W–90
0–76–E
–40°F (–40°C) to +35°F (+2°C)
75W
0–76–J
–40°F (–40°C) and up*
75W–140
0–76–L
–40°F (–40°C) and up*
75W–90
0–76–N
–40°F (–40°C) and up*
75W–140
0–76–M
* There is no upper limit on these ambient temperatures, but axle sump temperature must never exceed 250°F (121°C).
Table 3, Meritor Drive Axle Approved Lubricants
School Bus Chassis Maintenance Manual, July 2003
35/1
35
Rear Axle
35–02 Axle Lubricant Changing
and Magnetic Plug
Cleaning
A regular schedule for changing the axle lubricant in
a particular vehicle and operation can be accurately
determined by analyzing oil samples taken from the
axle at specified intervals or mileages. Lubricant suppliers frequently make their laboratory facilities available for determining the useful life of their product
under actual service conditions. The final schedule
that is recommended may, for economic reasons, be
correlated with lubricant changes that are governed
by climatic conditions and magnetic plug maintenance. Change lubricant type and viscosity as climatic temperatures demand, regardless of vehicle
mileage or established change schedule.
The normal operating temperature of compounded
lubricants during the summer season is about 160°
to 220°F (71° to 104°C). The chemicals and additives that give these lubricants increased loadcarrying capacity, oxidize faster at temperatures
above 220°F (104°C), contributing to more rapid lubricant deterioration. For this reason, lubricants of
this type, that operate continuously at high temperatures, must be changed more frequently.
CAUTION
Failure to change the axle lubricant at more frequent intervals, when adverse operating conditions require, could result in axle damage.
Alliance Brand Product (ABP) Axle
1. Remove the filler plug, then the drain plug (in the
center bottom of the axle housing), and allow the
differential to drain completely.
2. Install the drain plug and tighten it securely.
3. Fill the differential with 80/90 hypoid gear oil
through the rear axle fill hole. See Table 1 for
axle lubricant capacities.
NOTE: A normal oil change does not include the
hubs. Drain the differential and add 5.8 qts. (5.5
L) of SAE 80/90 hypoid gear oil through the rear
axle fill hole. The lubricant level should be at the
bottom of the fill hole.
35/2
IMPORTANT: The entire axle capacity (axle
completely dry) is 7.4 qts. (7 L). Each hub contains 0.80 qt. (0.75 L) of lubricant. To protect the
outer bearings from oil starvation, jack up (articulate) each side of the axle a minimum of 4
inches (10 cm) to ensure that oil flows to the
outer bearings. Articulate the short-side arm for
45 seconds and the long-side arm for 90 seconds. After articulating the axle, add 0.80 qt.
(0.75 L) of lubricant through the fill hole (in addition to the 5.8 qts. [5.5 L] of a normal oil
change) for each hub that has been removed.
Check the oil level again and ensure that the
axle is neither under nor overfilled.
4. Install the fill plug and tighten it securely.
Meritor Axle
Axle Draining and Flushing
1. Remove the plug at the bottom of the housing
and drain the lubricant while the unit is warm.
Allow enough time for all of the old lubricant to
drain completely.
2. Flush the unit with clean flushing oil, then drain it
completely.
IMPORTANT: Do not flush axles with solvent,
such as kerosene.
3. Clean the drain plugs. For magnetic drain plugs,
a piece of key stock or any other convenient
steel slug may be used to short the two magnetic
poles and divert the magnetic field.
NOTE: Meritor recommends using magnetic
plugs with elements having a minimum pickup
capacity of 2 pounds (1 kg) of low-carbon steel,
in plate or bar form. Magnets will rapidly lose
effectiveness as collected material bridges the
gap between the two poles. Clean or change
the plugs before this occurs. It may be necessary to clean or change the plugs one or more
times between lubrication change intervals.
4. After cleaning the drain plugs, install and tighten
them 35 lbf·ft (47 N·m).
School Bus Chassis Maintenance Manual, July 2003
Rear Axle
35
Axle Filling
1. With the vehicle on a level surface, fill the axle
housing to the bottom of the oil fill hole (in the
carrier or housing) with lubricant. See Table 2 for
axle lubricant capacities and see Table 3 for approved axle lubricants.
NOTE: Meritor axles have a small tapped and
plugged hole located near and below the housing oil fill hole. This smaller hole is for the lubricant temperature sensor only, and must not be
used as a fill or level hole.
2. Install the fill hole plug, and tighten it 35 lbf·ft (47
N·m).
3. After filling the carrier and housing assembly with
lubricant, drive the vehicle, unloaded, for 1 or 2
miles (2 or 3 kilometers) at speeds not to exceed
25 mph (40 km/h), to thoroughly circulate the
lubricant throughout the assembly.
35–03 Axle Breather Checking
NOTE: On ABP axles, the axle housing breather
is located on the carrier assembly.
The axle housing breather must remain unobstructed. Whenever the axle lubricant level is
checked, also check that the axle breather is open.
Check more often under poor operating conditions. If
the breather is plugged, clean or replace it as
needed.
School Bus Chassis Maintenance Manual, July 2003
35/3
Wheels and Tires
40
Index, Alphabetical
Title of Maintenance Operation (MOP)
MOP Number
Wheel Nut and Rim Nut Checking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40–01
School Bus Chassis Maintenance Manual, October 1996
40
Wheels and Tires
40–01 Wheel Nut and Rim Nut
Checking
Fig. 1, then tighten all of the outer wheel nuts in the
same sequence.
CAUTION
IMPORTANT: In addition to the maintenance
interval in this manual, check the wheel nut
torque the first 50 to 100 miles (80 to 160 km)
of operation after a wheel has been removed
and installed.
Too little wheel nut torque can cause wheel
shimmy, resulting in wheel damage, stud breakage, and extreme tire tread wear. Too much wheel
nut torque can break studs, damage threads, and
crack discs in the stud hole area.
When checking wheel nuts on a dual disc assembly,
remove one outer nut at a time, tighten the inner nut,
then reinstall the outer nut. Repeat this procedure for
all of the inner wheel nuts in the sequence shown in
See Table 1, Table 2, Table 3, or Table 4 for wheel
nut torque specifications, and see Fig. 1 for the tightening sequence.
Nut Size
Wheel
Manufacturer
Torque (dry threads):
lbf·ft (N·m)
3/4–16, 1-1/8–16
Accuride
450–500 (610–680)
Rear Wheel Inner Nut
3/4–16
Accuride
450–500 (610–680)
Rear Wheel Outer Nut
1-1/8–16
Accuride
450–500 (610–680)
3/4–16
Accuride
175–200 (235–270)
Description
Front Wheel Nut
Wheel Stud Retainer Nut
Table 1, Fastener Torque for 10-Hole Disc Wheel With Inner and Outer Locknuts
Description
Nut Size
Torque (lubricated threads):
lbf·ft (N·m)
M20
280–310 (380–420)
Front and Rear Wheel Nuts
Table 2, Fastener Torque for 8-Hole Disc Wheel With Cone Locknuts
Description
Nut Size
Torque (lubricated threads):
lbf·ft (N·m)
M22
390–500 (529–678)
Front and Rear Wheel Nuts
Table 3, Fastener Torque for 10-Stud Hub-Piloted Wheels
Size
Wheel
Manufacturer
Torque (dry threads):
lbf·ft (N·m)
Front Wheel Nut, 5- and
6-Spoke
3/4–10
Gunite
200–225 (270–305)
Rear Wheel Nut, 5- and
6-Spoke With Channel Spacer
(Fig. 2)
3/4–10
Gunite
200–225 (270–305)
Rear Wheel Nut, 5- and
6-Spoke With Corrugated
Channel Spacer (Fig. 3)
3/4–10
Gunite
240–260 (325–350)
Description
Table 4, Spoke-Type Wheel Fastener Torque
School Bus Chassis Maintenance Manual, October 1996
40/1
40
Wheels and Tires
2
1
10
7
4
5
6
8
3
A
1
1
1
8
3
3
6
5
4
6
3
5
7
4
9
2
4
5
2
2
C
B
D
f400057
05/27/93
A. 8-Stud Disc Wheel
B. 10-Stud Disc Wheel
C. 6-Spoke Wheel
D. 5-Spoke Wheel
Fig. 1, Wheel Nut and Rim Nut Tightening
f400033a
05/16/94
Fig. 2, Non-Corrugated Channel Spacer
f400032a
10/05/94
Fig. 3, Corrugated Channel Spacer
40/2
School Bus Chassis Maintenance Manual, October 1996
Driveline
41
Index, Alphabetical
Title of Maintenance Operation (MOP)
MOP Number
Driveline Inspecting and Lubricating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41–01
School Bus Chassis Maintenance Manual, April 1998
41
Driveline
• Spicer 1710 and 1760: 125 to 135 lbf·ft
(170 to 183 N·m)
41–01 Driveline Inspecting and
Lubricating
CAUTION
Inspecting
Before lubricating the driveline U-joints and slipjoints, make the following checks:
1. Check that the yoke-strap capscrews are tightened as follows: See Fig. 1, Ref. 4.
• Spicer SPL90 and 1610: 50 to 60 lbf·ft (68
to 81 N·m)
Do not overtighten the yoke-strap capscrews, due
to the extreme load occurring at high-speed rotation. A loose or broken capscrew at any point in
the driveline weakens the driveline connection,
which could eventually result in serious vehicle
damage.
12
2
6
5
4
3
1
10
11
2
9
8
4
13
7
14
7
17
15
16
18
3
10/06/94
f410057a
NOTE: Not all fasteners are shown.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Slip-Joint Assembly
Driveshaft Tube
Driveshaft Yoke
Input Shaft Half-Round End
Yoke
12. Rear Axle
Transmission
Half-Round End Yoke
U-Joint Assembly
Yoke Strap and Capscrew
Coupling Shaft
Midship Bearing and Mount
Bearing Cup
13.
14.
15.
16.
17.
18.
Splined Shaft
Dust Seal
Sleeve Yoke
Full-Round-Yoke Lug
U-Joint Cross
Lockplate and Capscrew
Fig. 1, Driveline Assembly With Midship Bearing
School Bus Chassis Maintenance Manual, April 1998
41/1
41
Driveline
2. Check each of the output and input end yokes
for cracks and looseness. See Fig. 1, Refs. 2
and 11. Replace cracked yokes. If any end yoke
can be moved in or out on its shaft, or can be
rocked on its shaft, disconnect the driveshaft and
U-joint from the end yoke. Check the drive component’s shaft seal for leakage or other visible
damage that may have been caused by the
loose yoke. Replace the seal if needed. Tighten
the end-yoke nut to the value in Table 1. If the
end yoke is still loose after tightening the yoke
nut, install a new yoke and yoke nut.
(123 N·m). Replace the midship bearing assembly if the rubber cushion is worn or oil-soaked.
5. Check the slip-joints for spline wear by trying to
bend the sleeve-yoke and splined shaft back and
forth. See Fig. 2. If looseness is greater than
0.007 inch (0.18 mm), replace both the sleeveyoke and the splined shaft.
End-Yoke Nut Torque Specifications
Description
Thread Size
Torque:
lbf·ft (N·m)
Transmissions
Fuller FS 4205A, 4205B,
5205B, 6305A/B, 5306A,
6306A
1-1/4–18
300–350
(405–475)
Allison AT545,542, MT &
MT643
1/2–20*
102–121
(138–164)
Attempt to bend the sleeve yoke and splined shaft back
and forth.
2–16
600–800
(815–1085)
Fig. 2, Slip-Joint Spline Wear Checking
Allison MD Series,
MD3060P
Single Axle Input Shaft
Coupling Shaft (Midship Bearings)
Spicer SPL90, 1610,
1710
1-1/4–18
475–525
(644–712)
* The Allison AT-545 transmission output shaft end-yoke is retained by a
1/2-20 x 1-1/2-inch bolt and a 1-1/16-inch washer. Both the bolt and the
washer must be replaced each time they are removed.
Table 1, End-Yoke Nut Torque Specifications
NOTE: If the end-yoke locknut was removed for
any reason, install a new one.
3. Check the U-joint assemblies for wear by attempting to move the driveshaft up and down,
and from side to side. If movement of the U-joint
trunnion in the bearings is greater than 0.006
inch (0.15 mm), replace the U-joint assembly.
4. Check the midship bearing and bracket for looseness and deterioration by attempting to move the
driveshaft up and down, and from side to side. If
the bearing is loose on its shaft, or rattles, replace it. If the bearing bracket is loose on the
frame, or the bearing mount is loose on the
bracket, tighten the mounting bolt nuts 91 lbf·ft
41/2
f410012a
05/27/93
6. Check the driveshaft tubes for dents, bends,
twists, or other damage. If any tube appears to
be damaged, remove the driveshaft and check
the runout on the tube. If the tube is not straight
(and cannot be straightened) within 0.005 inch
(0.127 mm) on the slip-joint seal surface of the
splined shaft, 0.010 inch (0.254 mm) on the tube
3 inches (76 mm) from the front and rear welds,
and 0.015 inch (0.381 mm) at the center of the
tube, replace the tube. See Fig. 3.
If the driveshaft tube requires straightening or
replacement, balance the repaired driveshaft before installing it. See Group 41 of the School
Bus Chassis Workshop Manual.
7. Check the driveshaft for missing balance
weights, and for debris build-up. Remove any
build-up. If any balance weights are missing, remove the driveshaft and have it balanced; see
Group 41 of the School Bus Chassis Workshop
Manual.
8. For driveshafts with slip-joints, check that the
yoke plug is not loose or missing. See Fig. 4,
Ref. 2. Replace the yoke plug if needed. If the
yoke plug is missing, the splined shaft may be
School Bus Chassis Maintenance Manual, April 1998
41
Driveline
U-Joint Lubricating
A
A
1. Wipe all old grease and dirt from each U-joint
grease fitting. See Fig. 4, Ref. 8.
2. Use a hand-type grease gun, or a high-pressure
gun with a low-pressure adapter, to lubricate the
U-joints.
B
C
C
D
f410110b
06/13/96
A.
B.
C.
D.
Measurement:
Measurement:
Measurement:
Measurement:
3" (76 mm)
0.005" (0.127 mm)
0.010" (0.254 mm)
0.015" (0.381 mm)
3. Using lithium 12 hydroxy stearate grease (NLGI
grade 1 or 2, with EP additives), lubricate until
new grease can be seen at all four U-joint seals.
Fig. 3, Driveshaft Runout Specifications
hitting the yoke plug and knocking it out; check
the driveshaft for proper length.
1
2
7
3
3
5/16–24 capscrews: 24 lbf·ft (32 N·m)
3/8–24 capscrews: 37 lbf·ft (50 N·m)
Bend the lockstrap tabs up, against a flat side of
each capscrew. If the capscrews were already
tight, or all of the U-joint seals still do not purge,
remove the bearing cup at that seal, and examine the seal for damage. If the seal is damaged,
replace the complete U-joint assembly.
6
8
3
IMPORTANT: Fresh lubricant must be seen escaping from all four bearing cup seals of each
U-joint.
On full-round yokes, if most of the grease being
added to a U-joint can be seen escaping from
just one of the U-joint seals, bend the tabs of
the lockstrap away from the heads of the bearing cup capscrews, then check the torque on
the bearing cup capscrews at that seal. Tighten
the bearing cup capscrews as follows:
5
4
NOTE: If a low-pressure adapter is not used
with the high-pressure gun, the U-joints may not
receive enough lubricant.
1
A
f410050a
10/20/93
A. After grease appears, cover the pressure-relief hole
while continuing to lubricate.
1. Slip-Joint Grease
5. Yoke Plug PressureFitting (with grease
Relief Hole
gun attached)
6. Slip-Joint Seal
2. Yoke Plug
7. Full-Round Yoke
3. Grease
8. U-Joint Grease Fitting
4. Half-Round Yoke
Fig. 4, Slip-Joint and U-Joint Lubricating
School Bus Chassis Maintenance Manual, April 1998
If grease does not appear at one of the seals,
use a screwdriver to pry the U-joint trunnion
away from the non-purging seal, or tap the
driveshaft or yoke with a plastic or rawhide mallet (on the side opposite the dry seal), while
continuing to apply gun pressure. If grease still
does not appear, bend the tabs of the lockstrap
away from the heads of the bearing cup capscrews, then loosen the bearing cup capscrews
(at the bearing with the dry seal) to relieve seal
tension. Lubricate the U-joint until the old
grease is purged, then tighten the capscrews to
the above specifications, and bend the tabs of
the lockstrap against a flat side of each cap-
41/3
41
Driveline
screw. If the bearing will not take grease, replace the U-joint assembly; see Group 41 of the
School Bus Chassis Workshop Manual.
4. Check the old grease. If it appears rusty, gritty, or
burned, replace the U-joint assembly. See Group
41 of the School Bus Chassis Workshop Manual.
5. Wipe any excess grease from the seals and
grease fittings.
Slip-Joint Spline Lubricating
1. Wipe all old grease and dirt from the slip-joint
grease fitting. See Fig. 4, Ref. 1.
2. Use a hand-type grease gun or a high-pressure
gun with a low-pressure adapter, to lubricate the
slip-joint. Using lithium 12 hydroxy stearate
grease (NLGI grade 1 or 2, with EP additives),
lubricate until fresh grease appears at the
pressure-relief hole in the yoke plug. Then cover
the relief hole with your finger, while continuing
to lubricate until fresh grease appears at the slipjoint seal. See Fig. 4, Ref. 6. This ensures complete lubrication of the splines.
3. Wipe any excess grease from the pressure-relief
hole, slip-joint seal, and grease fitting.
41/4
School Bus Chassis Maintenance Manual, April 1998
Brakes
42
Index, Alphabetical
Title of Maintenance Operation (MOP)
MOP Number
ABS Tone Rings Cleaning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42–13
Air Dryer Checking, Bendix AD–9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42–01
Air Dryer Desiccant Replacing, Bendix AD–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42–02
Air Dryer Inspecting, Bendix AD–9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42–03
Air Reservoir Automatic Drain Valve Disassembling, Cleaning, and Inspecting,
Bendix DV–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42–04
Automatic Slack Adjuster Lubricating and Checking, Meritor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42–05
Bendix Hydro-Max® Power Booster Checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42–06
Brake Caliper Slide Pin Lubricating, Bosch Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42–14
Brake Caliper Slide Rail Lubricating, Bosch Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42–15
Brake Lines Checking, Hydraulic Disc Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42–07
Brake Lining Wear Checking, Hydraulic Disc Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42–08
Camshaft Bracket Bushing Lubricating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42–09
Foot Brake Valve Actuator Lubricating, Bendix E–6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42–10
Front Air Brake Hose Inspecting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42–12
Relay Valve Checking, Midland . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42–11
School Bus Chassis Maintenance Manual, March 2003
Brakes
42–01 Air Dryer Checking,
Bendix AD–9
During cold-weather operation, check the operation
of the end cover heater and thermostat assembly.
1. With the ignition switch in the ON position, check
for voltage to the heater and thermostat assembly. Unplug the electrical connector at the air
dryer, and place the test leads of a voltmeter on
each of the pins of the male connector. If there is
no voltage, look for a blown fuse, broken wires,
or corrosion in the vehicle wiring harness. Check
that a good ground path exists.
2. Check the thermostat and heater operation. Turn
the ignition switch to the OFF position and cool
the end cover assembly to below 40°F (4°C).
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.
Warm the end cover assembly to over 90°F
(32°C) and again check the resistance. It should
exceed 1000 ohms. If it does, the thermostat and
heater assembly is operating properly. If it does
not, replace the purge-valve housing assembly,
which includes the heater and thermostat assembly.
42–02 Air Dryer Desiccant
Replacing, Bendix AD–9
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. To take maximum advantage of
desiccant life and ensure that replacement occurs
only when necessary, disassemble, clean, and inspect the air dryer. Replace the desiccant cartridge if
necessary. For instructions, see Group 42 of the
School Bus Chassis Workshop Manual.
42–03 Air Dryer Inspecting,
Bendix AD–9
1. Check the reservoirs for moisture. A small
amount (teaspoon or less) is normal. Larger
School Bus Chassis Maintenance Manual, March 2003
42
amounts may mean that the desiccant needs to
be replaced. Check the mounting and connecting
lines.
2. Tighten the fasteners that attach the air dryer to
the vehicle. Use the following torque values.
28 lbf·ft (38 N·m) for SAE grade 5, 3/8–16 fasteners.
135 lbf·ft (183 N·m) for SAE grade 5, 5/8–11 fasteners.
Check all air lines, fittings, and electrical connections for damage, leakage, or looseness.
3. Replace damaged or leaking parts, and tighten
loose fittings or electrical connections.
42–04 Air Reservoir Automatic
Drain Valve
Disassembling,
Cleaning, and
Inspecting, Bendix DV–2
Disassemble the drain valve, clean the parts with
mineral spirits, and inspect the parts. Replace all rubber parts and any worn or damaged parts; use only
genuine Bendix replacement parts or kits. Assemble
and install the valve, then check for proper operation
and leakage. For instructions, see Group 42 of the
School Bus Chassis Workshop Manual.
42–05 Automatic Slack
Adjuster Lubricating and
Checking, Meritor
1. Lubricate the slack adjusters using hightemperature, water-proof grease NLGI grade 1,
Texaco Thermotex EP 1, Shell Darina No. 1,
Marathon 528 heavy-duty, Sunaplex No. 1 EP,
Amdex No. 1 EP, or Philube B No. 1. It should
be smooth-textured, corrosion-resistant grease,
free of fillers and abrasives. See Fig. 1.
2. Check the boots for cuts, tears, etc., and replace
them if necessary.
3. Check the brake shoe lining wear to determine
the proper reline time.
42/1
42
Brakes
1
A
B
2
3
4
5
7
10/20/93
6
f420012a
1.
2.
3.
4.
5.
Brake Chamber
Clevis
Actuator Rod
Boot
Pressure-Relief Capscrew, Gasket, Pawl Spring,
and Pawl
6. Manual Adjusting Nut
7. Grease Fitting (or Lube Plug)
NOTE: For a drum brake, A minus B must equal 5/8" to
3/4" (16 to 19 mm).
A. With the brakes applied, measure this distance.
B. With the brakes released, measure this distance.
Fig. 2, Measuring Free-Stroke
Fig. 1, Meritor Automatic Slack Adjuster
4. Check the free-stroke. If the vehicle has new
brakes or brakes with new linings, you must
check the free-stroke. If the vehicle is in for routine maintenance and the brakes or linings are
not new, go to the next step and check the brake
chamber stroke.
IMPORTANT: Do not use installation templates to check the slack adjuster angles.
Installation templates are used only when
installing a new slack adjuster or reinstalling
the existing slack adjuster.
4.1
With the brakes fully released, measure
the distance from the bottom of the brake
chamber to the center of the large clevis
pin. See Fig. 2, Ref. A.
4.2
Use a pry bar to move the slack adjuster,
applying the brakes. Again, measure the
distance from the bottom of the brake
chamber to the center of the large clevis
pin. See Fig. 2, Ref. B.
The difference between the two measurements is the initial free-stroke, and sets
the clearance between the linings and the
42/2
f420180a
09/27/94
drum. The free-stroke must be 5/8 to 3/4
inch (16 to 19 mm).
4.3
If the free-stroke is incorrect, remove the
pressure-relief capscrew, gasket, pawl
spring, and pawl from the slack adjuster
housing. See Fig. 1, Ref. 5. If equipped
with a pull-pawl assembly, carefully insert
a screwdriver and raise the relief cap
about 1/8 inch (3.2 mm). See Fig. 3.
CAUTION
Before turning the adjusting nut, remove the pressure relief capscrew, spring, and pawl assembly. If
equipped with a pull-pawl assembly, raise the relief cap as instructed. Failure to do so could strip
the teeth on the pawl.
4.4
Turn the adjusting nut 1/8 turn, as shown
in Fig. 4. Measure the stroke again, and
adjust until correct.
CAUTION
Do not make the adjusted chamber stroke too
short. The free-stroke must not be less than the
School Bus Chassis Maintenance Manual, March 2003
42
Brakes
A
5.2
Build air pressure to 100 psi (690 kPa).
Shut down the engine. Fully apply the
brakes, then measure the distance from
the bottom of the brake chamber to the
center of the large clevis pin. See Fig. 2,
Ref. B. The difference between the measurements is the brake chamber stroke.
5.3
The brake chamber stroke must be less
than the measurements shown in
Table 1. If the brake chamber stroke is
incorrect, remove the pressure-relief capscrew, gasket, pawl spring, and pawl from
the slack adjuster housing. See Fig. 1,
Ref. 5. If equipped with a pull-pawl assembly, carefully insert a screwdriver and
raise the relief cap about 1/8 inch (3.2
mm). See Fig. 3.
f420693a
09/27/94
A. Insert screwdriver here.
Fig. 3, Pull-Pawl Assembly (sectional view)
A
B
Chamber Size
Effective Area:
square inches
Maximum
Allowable Stroke*:
inches (mm)
(B minus A)
12
Less than 1-3/8 (35)
16
Less than 1-3/4 (44)
20
Less than 1-3/4 (44)
24
Less than 1-3/4 (44)
24 Long Stroke
Less than 2 (51)
30
Less than 2 (51)
* Adjust the brakes whenever the applied stroke exceeds the maximum.
07/05/95
f420181a
A. Shorten stroke.
B. Lengthen stroke.
Table 1, Maximum Allowable Brake Chamber Stroke,
with Meritor Automatic Slack Adjusters
CAUTION
Fig. 4, Brake Stroke Adjusting
measurements given previously. If the chamber
stroke is too short, the linings can drag, which
could damage the brake.
4.5
If removed, install the pawl, pawl spring,
gasket, and pressure-relief capscrew.
Tighten the capscrew 15 to 20 lbf·ft (20 to
27 N·m). Or, remove the screwdriver from
the pull-pawl assembly (if so equipped).
5. Check for correct brake chamber stroke.
5.1
With the brakes fully released, measure
the distance from the bottom of the brake
chamber to the center of the large clevis
pin. See Fig. 2, Ref. A.
School Bus Chassis Maintenance Manual, March 2003
Before turning the adjusting nut, remove the pressure relief capscrew, spring, and pawl assembly. If
equipped with a pull-pawl assembly, raise the relief cap as instructed. Failure to do so could strip
the teeth on the pawl.
5.4
Turn the adjusting nut one-eighth turn, as
shown in Fig. 4. Measure the stroke
again, and adjust until correct.
If the stroke varies or remains greater
than the specified range, check the brake
components, including the camshafts,
camshaft bushings, anchor pins, rollers,
chamber brackets, clevis, and clevis pins.
42/3
42
Brakes
For instructions, see Group 42 of the
School Bus Chassis Workshop Manual.
5.5
If removed, install the pawl, pawl spring,
gasket, and pressure-relief capscrew.
Tighten the capscrew 15 to 20 lbf·ft (20 to
27 N·m). Or, remove the screwdriver from
the pull-pawl assembly (if so equipped).
42–06 Bendix Hydro-Max®
Power Booster Checking
To minimize the possibility of creating airborne brake
lining dust, clean the dust from the brake rotor, brake
caliper, and brake assembly, using an industrial-type
vacuum cleaner equipped with a high-efficiency filter
system. Then, using a rag soaked in water and
wrung until nearly dry, remove any remaining dust.
Do not use compressed air or dry brushing to clean
the brake assembly.
1. Check lining wear.
1.1
Apply the parking brake. Chock the tires
to prevent vehicle movement.
Check for proper operation; for instructions, see
Group 42 of the School Bus Chassis Workshop
Manual.
1.2
Remove one or more of the lining inspection plugs, and measure brake lining
thickness.
42–07 Brake Lines Checking,
Hydraulic Disc Brakes
1.3
On front and rear axles, replace linings
worn to less than 1/16 inch (1.6 mm).
1.4
Make sure that the brake rotor and linings
are free of oil and grease.
1.5
Install the inspection plug(s).
Check all hydraulic lines and fittings for damage,
leakage, or looseness.
Replace damaged or leaking components, and
tighten loose fittings.
42–08 Brake Lining Wear
Checking, Hydraulic
Disc Brakes
Before checking lining wear with the wheel removed,
review the following brake lining exposure warnings.
WARNING
Breathing brake lining dust (asbestos or nonasbestos) could cause lung cancer or lung disease. Unless exposure can be reduced below legal
limits, wear an air purifying respirator approved
by MSHA or NIOSH at all times when servicing the
brakes, starting with removal of the wheels and
continuing through assembly. To reduce asbestos
exposure below legal limits, apply one of the following methods: (1) An enclosed-cylinder vacuum
system equipped with a High Efficiency Particulate Air (HEPA) filter; (2) A solvent spray system
that keeps the asbestos-contaminated parts wet
until they can be placed in a sealed and labelled
plastic bag.
42/4
2. If the wheel and hub assembly is removed from
the axle, check lining wear. Replace the linings
on all brake assemblies if worn to less than 1/16
inch (1.6 mm) at the thinnest point.
NOTE: To replace the brake linings, see the applicable brake section in Group 42 of the
School Bus Chassis Workshop Manual.
42–09 Camshaft Bracket
Bushing Lubricating
Pump multipurpose chassis grease (NLGI grade 1 or
2) into the chamber bracket until it appears at the
slack adjuster end of the bracket. See Fig. 5. Use
care that no grease enters the drum cavity. If grease
leaks out under the camhead, the camshaft grease
seal is worn or damaged, or is installed backwards.
NOTE: The use of meter-type fittings, having a
maximum 40 psi (275 kPa) pressure relief at
shutoff, is recommended.
School Bus Chassis Maintenance Manual, March 2003
42
Brakes
42–11 Relay Valve Checking,
Midland
1
Chock the tires. Start the engine and run it long
enough to pressurize the air system to at least 80 psi
(550 kPa), then shut down the engine.
3
Repeat as necessary to maintain 80 psi (550 kPa)
pressure during this check.
2
05/28/93
A.
1.
2.
3.
A
f420011a
Clean off road grime from the relay valve, and any
debris from the valve exhaust port. Listen for air
leakage around the fittings or exhaust port. Tighten
the fittings as necessary. Use two wrenches to avoid
twisting the tubing.
Grease exit.
Brake Chamber
Slack Adjuster
Grease Fitting
If the valve fails this check, or is damaged, repair or
replace it; see the Midland Service Manual for instructions. Remove the chocks from the tires.
Fig. 5, Camshaft Bracket Bushing Lubrication
42–12 Front Air Brake Hose
Inspecting
42–10 Foot Brake Valve
Actuator Lubricating,
Bendix E–6
1. Remove the brake valve. For instructions, see
Group 42 of the School Bus Chassis Workshop
Manual.
2. From the outside of the cab, pull the valve away
from the frontwall and remove the brake plunger.
3. Wipe off the old grease from the plunger and the
adaptor.
4. Inspect the bore of the adaptor and the sliding
surface of the plunger. While some discoloration
is permissible, there should be no pitting or
roughness to the adaptor bore or the sliding surface of the plunger. If pitting or roughness exists,
replace damaged parts with new ones.
5. Lubricate the adaptor bore and the sliding surface of the plunger with an approved siliconebased grease, Dow Corning 55 O-Ring Lubricant
(formerly Molykote DC–55M), or Loctite® V–755
O-Ring Lubricant.
6. Using a new gasket, install the plunger and
brake valve following the instructions in Group
42 of the School Bus Chassis Workshop Manual.
School Bus Chassis Maintenance Manual, March 2003
1. Park the vehicle on a level surface. Shut down
the engine, set the parking brake, and chock the
rear tires. Open the hood.
2. Start the engine. Run it at idle until the air pressure gauges read at least 90 psi (620 kPa).
3. Shut down the engine.
4. Fully depress the brake pedal. Hold it down.
5. Without releasing the brake pedal, listen for a
steady hissing from the front brake hoses.
6. If no hissing is heard, the hoses do not leak.
7. Start the engine.
WARNING
The next step requires an assistant. Use caution
when working near the front wheels as they are
turned from side to side. Failure to use caution
could result in injury to the assistant.
8. While the assistant observes the hoses, turn the
wheels to full-lock, to one side and then the
other.
42/5
42
Brakes
CAUTION
The minimum bend radius is the bend that a hose
will withstand without stressing or kinking. The
hose should be straight for at least one hose diameter before starting to bend. The outside of a
hose may appear smooth even if the inner tube is
kinked. See Fig. 6.
IMPORTANT: Ensure that the hoses do not contact the tires or other parts and do not stress or
kink, especially at the metal sleeve, through the
entire range of motion.
9. Shut down the engine.
11/03/94
A
f420329a
NOTE: The center of the hose bend radius should be
well away from the fitting.
A. Bend Radius
Fig. 6, Bend Radius
10. If the hoses are leaking, contacting the tires or
other parts, kinking, or if the minimum bend radius is insufficient, replace both front brake
hoses and both front brake chamber fittings. See
Group 42 of the School Bus Chassis Workshop
Manual for more information.
42–13 ABS Tone Rings
Cleaning
CAUTION
An accumulation of road salt, dirt, and debris on
the antilock braking system (ABS) tone rings and
sensors can cause the ABS warning light to illuminate.
IMPORTANT: During winter months in areas
where corrosive materials are used on the highways, periodically clean the underside of the
42/6
vehicle to ensure proper ABS functioning. Thoroughly clean the wheel/ABS sensor/tone ring
areas, removing all corrosive materials.
42–14 Brake Caliper Slide Pin
Lubricating, Bosch
Brakes
NOTE: See the Bosch Pin Slide Disc Brakes
Service Manual for more information.
Apply 1/8 oz (3.5 g) Aeroshell grade 5 grease to
each of the two guide pin and guide pin bore sets.
See the Bosch Pin Slide Disc Brakes Service Manual
for additional information.
IMPORTANT: The later ZOH-T caliper has important differences from the early ZOPS caliper.
ZOPS calipers (since 1998) and ZOH-T calipers
(since 2002) use different slide pins and bolts.
See Fig. 7 and Fig. 8. The later trailing pin is
identified by notches and has a rubber bushing.
Flanged instead of hexbolts are used with the
later caliper. The later bolts have a fine thread
rather than a coarse thread pitch, are longer,
differently colored, and are tightened to a higher
torque specification. Use only the ZOH-T bolts
to assemble a ZOH-T caliper. The ZOPS caliper
bolts have a different thread pitch and will not
assemble correctly in a ZOH-T caliper mounting.
Also, the ZOH-T bolts will not assemble correctly in a ZOPS caliper. Do not interchange
parts. It is permissible to use both ZOH-T pins
and ZOH-T bolts in a ZOPS anchor plate, but
they must be replaced as sets. Both the pins
and the bolts must be changed.
XX
DANGER
The correct pins, bolts, and bolt torque must be
used. If not, brake function could be impaired and
lead to loss of control of the vehicle, which could
result in personal injury, death, or property damage.
IMPORTANT: The ZOH-T caliper assembly is
similar in appearance to the existing ZOPS caliper. The only obvious difference is that one of
the anchor plate slide pins (trailing side) has
School Bus Chassis Maintenance Manual, March 2003
42
Brakes
42–15 Brake Caliper Slide Rail
Lubricating, Bosch
Brakes
2
1
1. Raise the vehicle off of the ground and securely
support it with jack stands.
4
3
2. Remove the wheel from each wheel end. For
instructions, see Group 40 of the School Bus
Chassis Workshop Manual.
06/20/2002
f422357
1. Flanged Bolt
2. Leading Pin
3. Trailing Pin
4. Rubber Bushing
3. Place a stool near the axle to rest the caliper
upon after it is removed.
4. Remove the key retainer screw from the anchor
plate.
Fig. 7, ZOH-T Slide Pins and Bolts
5. Using a hammer and drift, carefully drive out the
key and spring. Be careful not to nick the anchor
plate rail.
6. Insert a large flat-bladed screwdriver through the
caliper vent window and into the rotor fins. Pry
the caliper outward; this will push the pistons
back slightly into the caliper, making removal
easier.
3
1
2
3
06/20/2002
f422358
1. Hexbolt
2. Blue Patch
3. Slide Pin
Fig. 8, ZOPS Slide Pins and Bolts
notches for identification. With ZOH-T calipers,
install the solid pin (no bushing) only in the anchor plate leading hole position. Install the pin
with the rubber bushing and notches only in the
anchor plate trailing hole position. Tighten the
leading-side pin first, then tighten the trailingside pin.
Tighten ZOH-T bolts 93 to 107 lbf·ft (126 to 145
N·m). Tighten ZOPS bolts 70 to 80 lbf·ft (95 to 108
N·m).
7. Grasping the caliper, swing it out and lift it from
the anchor plate. Rest the caliper on the stool.
For ease of removal, swing the caliper on the
forward anchor plate torque rail (the large one
opposite the key and spring rail).
8. Carefully remove the brake pads to avoid damage or getting grease on the pad face. Set them
aside.
9. Using brake cleaner or alcohol, remove old
grease and road accumulation from the caliper
V-ways, the anchor plate rails, and the shoe
slots. Also clean the key and spring.
10. Using a wire brush or wire wheel, remove any
remaining debris from the V-ways, rail, shoe
slots, key and spring.
11. Inspect the caliper to ensure that the piston
boots are in good condition with no punctures or
tears and are properly seated in the caliper.
Check to see that the heat shields are properly
seated. Repair or replace them if necessary.
12. Inspect the brake hoses for twists, cracks, blisters or abrasions, and replace them as necessary.
School Bus Chassis Maintenance Manual, March 2003
42/7
42
Brakes
13. Apply two level teaspoons of Aeroshell Grade 5
(ES–1246) grease on each side of the assembly.
Apply it evenly along the full length of the
V-groove and anchor plate rail, and apply one
level teaspoon evenly on both sides of the key
and spring. Any accumulation of grease after
caliper installation is done should be packed at
each end of the rail and along the top of the rail
or key at the V-groove.
14. Being careful not to get grease or dirt on the pad
face, reinstall each brake pad.
15. Grasping the caliper firmly, rest the V-ways on
the forward anchor plate torque rail (the large
rail) and swing the caliper into place. Make sure
that the brake hose is not twisted. Do not get
grease on the pad faces or rotor surfaces.
16. With the caliper installed and firmly seated on
the forward rail (large rail), insert the key and
spring between the caliper V-way and the anchor
rail from the inboard end of the anchor rail.
17. Carefully drive the key and spring into place. Install the key retainer screw and tighten 12 to 18
lbf·ft (16 to 24 N·m).
18. Install the wheels. For instructions, see Group
40 of the School Bus Chassis Workshop Manual.
19. Before moving the vehicle, press the brake pedal
several times to bring the pistons back to the
normal position.
42/8
School Bus Chassis Maintenance Manual, March 2003
Steering
46
Index, Alphabetical
Title of Maintenance Operation (MOP)
MOP Number
Drag Link Lubricating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46–02
Power Steering Reservoir Fluid Level Checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46–03
Power Steering Reservoir Fluid and Filter Changing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46–04
Steering Driveline Lubricating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46–01
Steering Gear Lubricating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46–05
School Bus Chassis Maintenance Manual, October 1996
46
Steering
46–01 Steering Driveline
Lubricating
2. Using a pressure gun, apply multipurpose chassis grease at the grease fittings until old grease
is forced out of the socket.
Wipe the grease fittings clean. See Fig. 1. Using a
pressure gun, apply a lithium-based grease (NLGI
grade 2) sparingly to the universal joints and slip-joint
splines.
NOTE: Use multipurpose chassis grease NLGI
grade 1 (6% 12-hydroxy lithium stearate grease)
or NLGI grade 2 (8% 12-hydroxy lithium stearate grease). The grade 2 chassis grease is preferred.
46–02 Drag Link Lubricating
1. Using a clean rag, wipe the dirt from both grease
fittings on the drag link. See Fig. 2.
6
1
5
4
3
7
2
1
7
6
f460516a
10/05/94
1. Pinch Bolt
2. Universal Joint Shaft
3. Bushing
4. Boot
5. Boot Retainer
6. Prevailing Torque Locknut
7. Grease Fitting
Fig. 1, Steering Driveline
School Bus Chassis Maintenance Manual, October 1996
46/1
46
Steering
1
1
2
2
10/05/94
f460926
1. Grease Fitting
2. Drag Link (pitman arm end shown)
Fig. 2, Steering Drag Link Lubricating
46–03 Power Steering
Reservoir Fluid Level
Checking
1. Clean around the power steering reservoir dipstick (fill cap) with a clean rag, then remove the
dipstick. See Fig. 3.
WARNING
Fill only with approved clean fluid. Do not mix
fluid types. Any mixture or any unapproved fluid
could lead to seal deterioration and leaks. Fluid
leakage could cause loss of power steering assist,
possibly resulting in personal injury and property
damage.
2. With the power steering fluid at operating temperature, check the fluid level on the dipstick. If
below the "add" mark, add enough fluid to bring
the level up to the full mark on the dipstick. See
Table 1 for approved power steering fluid.
3. Install the dipstick (fill cap) in the power steering
reservoir.
f460514a
10/05/94
1. Power Steering Fluid Reservoir
2. Steering Gear
Fig. 3, Power Steering Reservoir
46–04 Power Steering
Reservoir Fluid and
Filter Changing
1. Remove the dipstick, 3/8–16 hexnut, and cover.
See Fig. 3.
2. Drain the power steering reservoir by disconnecting the power steering gear-to-reservoir hose
from the reservoir. Keep the hose in an upright
position to prevent drainage of fluid.
3. Catch the fluid from the reservoir in a drain
bucket, then cap the reservoir port.
4. Lift out the spring and filter element.
5. Thoroughly clean the reservoir with a lint-free
cloth.
6. Install a new filter element, and position the
spring on top of the filter element.
Fluid Type
Approved
Fluid
Automatic Transmission Fluid
Dexron II*
* Use the same lubricant when assembling parts as is used in the power
steering system. See the Warning above.
Table 1, Approved Power Steering Fluid
46/2
School Bus Chassis Maintenance Manual, October 1996
46
Steering
7. Fill the reservoir with approved power steering
fluid. See Table 1.
2. Using a hand-type grease gun, apply multipurpose chassis grease until the grease starts coming out of the sector shaft dirt and water seal.
WARNING
Fill only with approved clean fluid. Do not mix
fluid types. Any mixture or any unapproved fluid
could lead to seal deterioration and leaks. Fluid
leakage could cause loss of power steering assist,
possibly resulting in personal injury and property
damage.
8. Place the disconnected end of the steering gearto-reservoir hose in a drain bucket. Do not start
the engine while draining the system. Raise the
front of the vehicle with a floor jack and support
it with jack stands. Have someone turn the steering wheel to full lock left and right, and capture
the fluid flowing from the hose in the drain
bucket. Add fluid to the reservoir, as needed.
Continue turning the steering wheel until clean
power steering fluid flows from the hose into the
drain bucket. Remove the plug from the reservoir
and reconnect the steering gear-to-reservoir
hose to the reservoir.
1
04/13/93
f460515a
1. Sector Shaft Grease Fitting
Fig. 4, Sector Shaft Lubricating, Ross TAS Series
9. Tighten the hose fitting nut finger-tight, then with
a wrench, tighten until there is firm resistance.
Tighten one-sixth turn more. Do not overtighten.
Remove the jack stands and lower the vehicle.
10. Fill the reservoir with approved fluid, as needed.
Start the engine and let it idle. Have someone
turn the steering wheel from lock to lock until no
bubbles are seen in the reservoir. Turn off the
engine.
11. Install a new cover gasket, the cover, and the
3/8–16 hexnut. Tighten the hexnut 28 lbf·ft (38
N·m). Install the dipstick.
12. Start the engine and check the power steering
reservoir fluid level. If the fluid level is low, add
more of the approved fluid to bring the level up
to the full mark on the dipstick.
46–05 Steering Gear
Lubricating
1. Wipe off debris from the grease fitting. See
Fig. 4.
School Bus Chassis Maintenance Manual, October 1996
46/3
Fuel
47
Index, Alphabetical
Title of Maintenance Operation (MOP)
MOP Number
Inline Fuel Strainer Replacing, Cummins ISB02 and MBE900 Engines. . . . . . . . . . . . . . . . . . . . . . . . . . . 47–01
School Bus Chassis Maintenance Manual, May 2005
Fuel
47
47–01 Inline Fuel Strainer
Replacing, Cummins
ISB02 and MBE900
Engines
NOTE: Vehicles with a Cummins ISB02 or
MBE900 engine have an inline fuel strainer. The
inline fuel strainer is located on the left-hand
frame rail under the cowl area.
1. Remove the brackets on each end of the fuel
stainer.
2. Remove the P-clip.
IMPORTANT: The fuel flow arrow on the fuel
strainer must be pointed toward the front of the
vehicle.
3. Remove the strainer, and replace it with a new
strainer.
4. Install the P-clip.
5. Install the brackets on each end of the fuel
strainer.
School Bus Chassis Maintenance Manual, May 2005
47/1
Exhaust
49
Index, Alphabetical
Title of Maintenance Operation (MOP)
MOP Number
Exhaust System Inspecting (Noise Emission Controls). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49–01
School Bus Chassis Maintenance Manual, October 1996
49
Exhaust
49–01 Exhaust System
Inspecting (Noise
Emission Controls)
NOTE: In addition to the maintenance interval in
this manual, inspect the exhaust system if the
vehicle has a noticeable increase in noise level
at any time. Replace parts that show leakage,
wear, or damage.
1. Check the muffler body, muffler outlet stack, muffler shield, and inlet tubes, for leakage, dents,
corrosion, or holes in the muffler.
2. Inspect the exhaust pipe for leakage, wear, or
damage; replace with new parts, if needed. Do
not reuse wide-band clamps. Once a clamp is
removed, it must be replaced.
On Caterpillar and Cummins engines, check for
leakage at the V-type clamp that attaches the
exhaust pipe to the turbocharger exhaust outlet.
If leakage exists, tighten the nut on the V-type
clamp 50 lbf·in (560 N·cm). Using a plastic hammer, tap around the clamp, then tighten again to
50 lbf·in (560 N·cm). If leakage persists, replace
the clamp.
3. Check for leakage at each wide-band exhaust
clamp. See Fig. 1. If leakage exists, tighten the
nuts on Torca "Torctite" exhaust clamps 40 to 60
lbf·ft (54 to 81 N·m). If leakage persists, install a
new wide-band exhaust clamp. See Section
49.00 of the School Bus Chassis Workshop
Manual for procedures.
f490005a
10/05/94
Fig. 1, Wide-Band Exhaust Clamp
School Bus Chassis Maintenance Manual, October 1996
49/1
Electrical, Instruments, and Controls
54
Index, Alphabetical
Title of Maintenance Operation (MOP)
MOP Number
Electrical Wiring Checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54–02
Ground Cables Checking and Cleaning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54–01
School Bus Chassis Maintenance Manual, October 1996
54
Electrical, Instruments, and Controls
54–01 Ground Cables
Checking and Cleaning
Check that the ground cables are clean, undamaged,
and tight. If needed, disconnect them, clean the mating surfaces with a soda solution, then connect them
securely. Spray the ground cable connections with
dielectric red enamel. See Table 1 for approved part
numbers.
Material
Part Number
Dielectric Grease
48–02349–000
Dielectric Red Enamel
Spray
MMM 1602 IVI SpraySealer (Spray-On B–6–665)
3. Check the turn-signal flasher. Make sure that the
two male and female connectors are firmly connected. Check that the flasher fuse is firmly
seated in its holder.
4. Test the electric horn. If it does not work, check
the adjustment screw on the horn unit. Turn the
screw in or out, until the horn works. If the horn
still does not work, check the wiring to it. If the
wiring checks out okay, replace the horn.
5. Check all the connectors on the right-hand side
of the bulkhead, inboard of the radiator surge
tank. See Fig. 2. Check the terminals for tightness, signs of damage, corrosion, and presence
of dirt. Repair, replace, or clean the terminals
and connectors, as needed.
Table 1, Approved Dielectric Grease and Red Enamel
54–02 Electrical Wiring
Checking
1
3
4
Dash and Cowl Area
5
7
6
1. Uncover the electrical power center located under the dash and remove the fasteners. See
Fig. 1.
2
9
08/23/96
1.
2.
3.
4.
5.
Surge Tank
Magnetic Switch
Bulkhead
Power Stud
ABS Connector
8
f541351
6. Engine Connector
7. Ground Stud
8. Electronic Engine
Connector (if installed)
9. Chassis Connector
Fig. 2, Bulkhead Electrical Connectors
Chassis
1. Check the main wiring harness. Check the wiring
insulation for damage from chafing or heat. Also
check for kinks. Reroute, repair, or replace the
wires as needed.
08/09/96
f541333
Fig. 1, Under-Dash Electrical Power Center
2. Check that all the relays are firmly seated in their
mounting blocks.
School Bus Chassis Maintenance Manual, October 1996
2. Disconnect the battery cables from the battery
posts, and check for corrosion.
If corrosion is found, clean the terminals and
posts, using a wire brush and a solution of baking soda and water. Use the solution sparingly.
54/1
54
Electrical, Instruments, and Controls
3. Apply dielectric grease liberally to all battery terminal pads. Connect the cables to the batteries,
and tighten them 10 to 15 lbf·ft (14 to 20 N·m).
Cover the terminals and spray each connection
with dielectric red enamel. See Table 1 for approved brands of dielectric grease and red
enamel.
54/2
School Bus Chassis Maintenance Manual, October 1996
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