User's Manual

9
Unloader leakage is exhibited by excessive compressor
cycling between the loaded and unloaded condition.
1. With service and supply system leakage below the
maximum allowable limits and the vehicle parked, bring
system pressure to governor cut-out and allow the
engine to idle.
2. The compressor should remain unloaded for a minimum
of 5-10 minutes. If compressor cycling occurs more
frequently and service and supply system leakage
is within tolerance, replace the compressor or repair
the compressor unloader system using a genuine
Bendix maintenance kit available from authorized
Bendix parts outlets.
COMPRESSOR REMOVAL & DISASSEMBLY
GENERAL
The following disassembly and assembly procedure is
presented for reference purposes and presupposes that
a rebuild or repair of the compressor is being undertaken.
Several maintenance kits are available and the instructions
provided with these parts and kits should be followed in
lieu of the instructions presented here.
MAINTENANCE KITS & SERVICE PARTS
Cylinder Head Maintenance Kit.
Unloader Maintenance Kit.
All components shown in Figure 10 with a key number are
available in kits and/or as individual service parts.
COMPRESSOR TROUBLESHOOTING
IMPORTANT: The troubleshooting contained in this section
considers the compressor as an integrated component of
the overall air brake charging system and assumes that
an air dryer is in use. The troubleshooting presented will
cover not only the compressor itself, but also other charging
system devices as they relate to the compressor.
GENERAL SAFETY GUIDELINES
WARNING! PLEASE READ AND FOLLOW
THESE INSTRUCTIONS TO AVOID
PERSONAL INJURY OR DEATH:
When working on or around a vehicle, the following
general precautions should be observed at all times.
1. Park the vehicle on a level surface, apply the parking
brakes, and always block the wheels. Always wear
safety glasses.
2. Stop the engine and remove ignition key when working
under or around the vehicle. When working in the
engine compartment, the engine should be shut
off and the ignition key should be removed. Where
circumstances require that the engine be in operation,
EXTREME CAUTION should be used to prevent
personal injury resulting from contact with moving,
rotating, leaking, heated or electrically charged
components.
3. Do not attempt to install, remove, disassemble or
assemble a component until you have read and
thoroughly understand the recommended procedures.
Use only the proper tools and observe all precautions
pertaining to use of those tools.
4. If the work is being performed on the vehicle’s air brake
system, or any auxiliary pressurized air systems, make
certain to drain the air pressure from all reservoirs
before beginning ANY work on the vehicle. If the
vehicle is equipped with an AD-IS
®
air dryer system or
a dryer reservoir module, be sure to drain the purge
reservoir.
5. Following the vehicle manufacturer’s recommended
procedures, deactivate the electrical system in a
manner that safely removes all electrical power from
the vehicle.
6. Never exceed manufacturer’s recommended pressures.
7. Never connect or disconnect a hose or line containing
pressure; it may whip. Never remove a component or
plug unless you are certain all system pressure has
been depleted.
8. Use only genuine Bendix
®
replacement parts,
components and kits. Replacement hardware, tubing,
hose, fi ttings, etc. must be of equivalent size, type
and strength as original equipment and be designed
specifi cally for such applications and systems.
9. Components with stripped threads or damaged parts
should be replaced rather than repaired. Do not
attempt repairs requiring machining or welding unless
specifi cally stated and approved by the vehicle and
component manufacturer.
10. Prior to returning the vehicle to service, make certain all
components and systems are restored to their proper
operating condition.
11. For vehicles with Automatic Traction Control (ATC),
the ATC function must be disabled (ATC indicator
lamp should be ON) prior to performing any vehicle
maintenance where one or more wheels on a drive
axle are lifted off the ground and moving.