TM 9-4940-568-20
2-85
Table 2-11. Air Compressor Troubleshooting
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1. OIL IN DISCHARGE AIR.
Clogged intake filter.
Replace intake filter (Para 11-6).
Oil viscosity too low.
Drain and fill with higher viscosity oil (Para 11-9).
Oil level too high.
Drain to correct level (Para 11-9).
Detergent type oil being used.
Change to non-detergent type with rust and oxidation inhibitor.
Oil control ring broken or not seated in, stuck in groove, rough, scratched, or excessive end gap.
Replace air compressor (Para 11-2).
Cylinders or piston rings scratched, worn or scored.
Replace air compressor (Para 11-2).
2. KNOCKS OR RATTLES.
Loose belt wheel or motor pulley or motor with excessive end play in shaft.
Replace air compressor (Para 11-2).
Leaking, broken, or loose valves.
Replace air compressor (Para 11-2).
Leaking, broken or worn inlet unloader parts. Aux. valve dirty, seats worn.
Replace air compressor (Para 11-2).
Worn or scored connecting rod, piston pin or crank pin bearings.
Replace air compressor (Para 11-2).
