Section 2
Troubleshooting
Maintenance Manual MM-0204 Copyright 2002
Issued 08-02 ArvinMeritor, Inc. Page 7
Compressor leaks
engine coolant
Loose fitting Check fittings at compressor and engine for leaks and verify
fittings are properly torqued.
Cracked coolant port Replace cylinder head.
Porosity in cylinder head Replace cylinder head.
Leaking of gasket internal to the
cylinder head
Verify cylinder head bolts are properly torqued. Make necessary
adjustments.
Inspect gasket for cracks or signs of wear. Replace if necessary.
Replace cylinder head.
None of the above, but condition
persists
Replace compressor.
Compressor pressurizes
coolant system or
coolant leakage to
compressor inlet
Leaking of gasket internal to the
cylinder head
Inspect gasket. Replace if necessary.
Cavitation or corrosion in
cylinder head
Replace cylinder head.
Porosity in cylinder head or
cylinder head cracked
Replace cylinder head.
None of above, but condition
persists
Replace the compressor.
Unloader leakage
Possible internal damage,
including worn or damaged
unloader piston O-ring, porosity
in unloader piston bore, loose or
leaking seal at unloader piston
bore
Replace compressor cylinder head assembly.
Compressor head gasket
failure
Discharge line blocked due to
freezing or carbon build-up
Check for trap (low spots) in lines.
Make necessary repairs.
Clear discharge line. Replace line if necessary.
Check for carbon build-up. If carbon build-up is present, replace
the discharge line.
Frozen or blocked line to
governor
Clear blocked line. Replace line if necessary.
Check for air dryer malfunction. Repair or replace as required.
Refer to the air dryer manufacturer’s maintenance manual for
service information.
Governor malfunction Repair or replace the governor. Refer to governor manufacturer’s
maintenance manual for service information.
Improper cylinder head bolt
torque, machining defect on
cylinder head or block, defective
cylinder head gasket
Inspect gasket. Replace if necessary. Verify all bolts are properly
torqued. If problem persists, replace cylinder head.
None of the above, but condition
persists
Replace compressor cylinder head assembly.
Table A: Compressor Troubleshooting Guide (Continued)
Condition Possible Cause Solution