Makita MAC5501G Instruction Manual - Page 17

TROUBLE SHOOTING PROBLEM Excessive vibration Compressor Knocks Compressor uses too much oil POSSIBLE CAUSE System pressure leaking back through check valve when compressor is stopped. Wrong oil being used Loose compressor, engine or engine guard Compressor not level Leg bolts over tightened to floor Excessive discharge pressure Wrong oil being used Loose flywheel, drive, pulley or drive belts Worn connector rods, wrist pin or main bearings Compressor valves loose or broken Check valve knocks at low pressure Clogged inlet filter Wrong oil being used, wrong viscosity Oil level too high Crankcase breather valve malfunction Compressor runs unloaded too long CORRECTIVE ACTION Check and replace check valve if necessary Drain and replace with proper oil Tighten components Level compressor Loosen leg bolts Reduce operating pressure Drain and replace with proper oil Tighten loose components and check belts Check and replace worn parts Check and replace worn or broken valves Remove and clean check valve Clean inlet filter or replace as necessary Drain and replace oil Fill compressor with oil to proper level Replace crankcase breather Increase load or stop compressor when not needed. Check for air leaks Page 17