HARNESS AS-REAR 4440387 - Caterpillar

air compressor is mounted on the left front of the engine. The air compressor is gear-driven by the same accessory drive as the auxiliary water pump.The air compressor uses pressure oil from the engine through oil pressure line to lubricate the crankshaft bearings. The oil then goes through oil drain line back to the engine oil pan.The coolant inlet line takes coolant from the pressure side of the auxiliary water pump. The coolant is sent through cylinder head of air compressor. The coolant is then sent back through coolant outlet line to inlet side of auxiliary water pump.The inlet air comes from the intake manifold through air inlet line, and the pressurized air leaves through pressure air outlet line, through the air dryer and then on to the main air reservoir. Air system pressure sensing lines monitor the system pressure and the signal is sent to the air compressor governor. The governor controls the activation of the air compressor.