COVER 1622224 - Caterpillar

Illustration 1 g00763277
View from the Right Side of the Tractor Engine (1) Air compressor (2) Air compressor governorThe air compressor is located on the right side of the engine. The air compressor governor controls the operating pressure of the air compressor. Air compressor governor (2) senses the reservoir pressure. If the reservoir pressure is low, nothing happens within the governor and compressor (1) continues to function. When the reservoir pressure reaches the maximum cut-out setting of 827 34 kPa (120 5 psi), air pressure moves the governor piston against the governor spring which allows air to flow from governor (2) to the compressor unloading valves. The compressed air that is acting against the unloading valves holds the valves open. The open unloading valves stop the delivery of air from compressor (1) .When the reservoir pressure drops to the minimum cut-in pressure of 620 kPa (90 psi), the force of the governor spring returns the governor piston in order to stop the flow of air from the reservoir to the compressor unloading valves. The compressor unloading valves close and compressor (1) delivers air to the reservoir.Also, the solenoid valve for the air compressor governor will close when the air pressure drops below 585 kPa (85 psi) in any of the air reservoirs. When the solenoid valve closes, the air pressure to the air compressor governor will be closed off. When the air pressure is stopped, the air compressor will continue to charge the air system. The solenoid valve will open when the lowest air pressure in any of the air reservoirs is 758 kPa (110 psi). When the solenoid valve opens, air pressure will flow to the air compressor governor. The air compressor will continue to supply air pressure to the air reservoirs until the air pressure reaches 827 34 kPa (120 5 psi). When the air pressure reaches the cut-out pressure, the air pressure will cause the air compressor governor to stop the flow of air from the air compressor to the air reservoirs.