VALVE GP-CONTROL 9T1483 - Caterpillar

Symptom
Oil is leaking from the air compressor.Probable Cause
Damaged gasket for mounting the compressorCheck the torque of the bolts that mount the air compressor to the engine. Replace the gasket that is between the mounting flange of the air compressor and the engine. Tighten the bolts to the torque that is listed in the specifications section.
Damaged rear coverCheck the rear cover on air compressors that do not have a rear accessory. Check for cracks in the rear cover. Check the torque of the bolts that mount the rear cover.
Damaged rear cover gasketCheck the torque of the bolts that mount the rear drive. Replace the gasket that is between the mounting flange of the air compressor and the accessory. Tighten the bolts to the torque that is listed in the specifications section.
Cracked crankcase or rear coverInspect the exterior of the air compressor for components that are cracked or broken. Mounting bolts that are loose may cause the crankcase to crack. A cracked rear cover can be caused by using too much torque to tighten fittings that connect to the rear cover. Replace the air compressor if the crankcase is cracked.
The rear cover is loose.Check the rear cap bolts. Tighten the bolts, if necessary.
Leaking oil supply line or fittingsCheck that all fittings are tightened to standard torque. Tighten the fittings, if necessary. Check the oil line for damage. Replace the oil line, if necessary.
The casting of the air compressor is porous.Replace the air compressor if porosity is found.
The mounting flange gasket is missing or damaged.Replace the gasket, if necessary.
The O-ring for the end cover is missing or damaged.Replace the O-ring, if necessary.