TRUCK SERVICE MANUAL
Service compressor air strainer. Remove and
Remove compressor discharge valve cap nuts and
wash all parts including curled hair in 'leaning solvent.
check for presence of excessive carbon deposits. Also,
Saturate curled hair with clean engine oil and squeeze
check the discharge line for carbon. If excessive carbon
dry before replacing it in the strainer.
is found in either check, the cylinder head or discharge
line should be cleaned or replaced.
Check compressor mounting and drive
If compressor is self lubricated type, service
alignment, belt tension, etc. Adjust if necessary.
Clean and wash breather in
10, 000 Miles:
If the compressor is lubricated from the engine, clean oil
supply line to compressor. Also clean oil return line to
If compressor is self lubricated type, the oil should
be drained and the compressor crankcase flushed and
refilled with clean engine oil.
Depending upon operating conditions and
experience, disassemble compressor, clean and inspect
all parts thoroughly. Repair or replace all worn or
Compressor Passes Excessive Oil
Compressor Fails to Maintain Adequate pressure in the
1. Excessive wear.
1. Dirty intake strainer.
2. Dirty air strainer.
2. Excessive carbon in compressor cylinder head
3. Excessive oil pressure.
or discharge line.
4. Oil return line or passage to engine compressor
3. Discharge valves leaking.
4. Excessive wear.
5. Oil seal ring in end cover excessively worn.
5. Drive belt slipping.
6. Back pressure from engine crankcase.
6. Inlet valves stuck open.
7. Piston rings improperly installed.
7. Excessive leakage of inlet valves.
Compressor Does Not Unload
1. Loose drive pulley.
1. Defective unloading piston grommet.
2. Excessive carbon in cylinder head or damaged
2. Unloading cavity plugged with carbon.
3. Unloading mechanism binding or stuck.
4. Excessive wear.