Symptom Tree t004
| Cause | Correction |
|---|
|
Air intake system restriction to air compressor is excessive |
Replace the air compressor air cleaner (if installed). Check the air intake piping. Check engine air intake restriction if the air compressor inlet is plumbed to the vehicle or equipment intake system. Refer to Procedure 010-031. |
 |
|
Air system leaks |
Block the vehicle wheels and check the air system for leaks with spring brakes applied and released. Check for leaks from the air compressor gaskets and the air system hoses, fittings, tanks, and valves. Refer to the Master Repair Manual, Holset® Air Compressor, Bulletin 3666121, and the OEM service manual. |
|
|
Air governor is malfunctioning or not set correctly |
Check the air governor for correct operation. Refer to the Master Repair Manual, Holset® Air Compressor, Bulletin 3666121, and the OEM service manual. |
|
|
Carbon buildup is excessive in the air discharge line, check valve, or cylinder head |
Check for carbon buildup. Replace the air compressor discharge line, if necessary. Check the turbocharger for oil leaks. Check the intake tube for oil. Refer to Procedures 012-003 and 010-049. |
|
|
E-type system is not plumbed correctly |
Install an Econ valve, a check valve, and system hoses. Refer to the Master Repair Manual, Holset® Air Compressor, Bulletin 3666121. |
|
|
Air system component is malfunctioning |
Check the operation of check valves, alcohol evaporators, air dryers, and other OEM-installed air system components. Refer to the OEM service manual. |
|
|
Unloader valve is malfunctioning |
Check the unloader valve and unloader body seal. Refer to the Master Repair Manual, Holset® Air Compressor, Bulletin 3666121. |
|
|
Air compressor intake or exhaust valve leaks air |
Inspect the air compressor intake and exhaust valve assemblies. Refer to the Master Repair Manual, Holset® Air Compressor, Bulletin 3666121, and the OEM service manual. |
