14
Air Brake Charging System Troubleshooting
1.0 Oil Test Card
Results
Not a valid test.
Discontinue using this test.
Do not use this card test to diagnose compressor
"oil passing" issues. They are subjective
and error prone. Use only the Bendix Air
System Inspection Cup (BASIC) test and the
methods described in this guide for advanced
troubleshooting.
The Bendix
®
BASIC test should be the
definitive method for judging excessive
oil fouling/oil passing.
(See Appendix A,
on page 27 for a flowchart and expanded
explanation of the checklist used when
conducting the BASIC test.)
Symptom:
What it may indicate:
What you should do:
How to use this guide:
Find the
symptom(s)
that you see, then move to the right
to find the possible causes (“
What it may indicate
”) and
remedies (“
What you should do
”).
Review the warranty policy before performing any intrusive
compressor maintenance. Unloader or cylinder head gasket
replacement and resealing of the bottom cover plate are
usually permitted under warranty. Follow all standard safety
procedures when performing any maintenance.
Look for:
Normal - Charging system is working within
normal range.
Check - Charging system needs further
investigation.
Bendix
®
BASIC Test
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 as-
semble 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 sys-
tem, 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 pro-
cedures, 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, fittings, etc.
must be of equivalent size, type and strength as original
equipment and be designed specifically for such applica-
tions and systems.
9. Components with stripped threads or damaged parts
should be replaced rather than repaired. Do not attempt
repairs requiring machining or welding unless specifically
stated and approved by the vehicle and component manu-
facturer.
10. Prior to returning the vehicle to service, make certain all
components and systems are restored to their proper
operating condition.
11. For vehicles with Antilock Traction Control (ATC), the ATC
function must be disabled (ATC indicator lamp should be
ON) prior to performing any vehicle maintenance where
one or more wheels on a drive axle are lifted off the ground
and moving.
