WIRING GP-PAYLOAD SENSOR 4549856 - Caterpillar

Illustration 1 g01202915
Schematic for the Hydraulic Fan System
(1) Hydraulic fan motor. (2) Fluid sampling port. (3) Makeup valve. (4) Valve. (5) Pressure and flow compensator. (6) Hydraulic fan pump. (7) Hydraulic tank. (8) Filter group. (9) Check valve (hydraulic oil cooler bypass). (10) Hydraulic oil cooler.
Illustration 2 g01202916
Hydraulic Fan System (Right Side View)
The hydraulic fan system is used to cool the following components: the engine, the hydraulic oil, the transmission oil and the air conditioning system.The hydraulic fan system is made up of the following components: piston pump (6), hydraulic tank (7), valve (4), hydraulic motor (1), hydraulic oil cooler (10), bypass valve (9), makeup valve (3) and filter (8). The hydraulic fan pump is a variable displacement piston pump. The pump is mounted on the steering pump. The pump is located under the cover behind the cab. If the machine is equipped with the high ambient temperature cooling arrangement, the output of the hydraulic pump will increase. The pump pulls oil from hydraulic tank (7). Pressurized hydraulic oil from the pump is sent to the hydraulic motor (1). Hydraulic motor (1) is a fixed displacement bent axis motor. The speed of the motor depends on the amount of oil flow from the pump. The oil flows out of the motor and through the hydraulic oil cooler.The hydraulic fan system is equipped with a makeup valve (3) that is attached to the motor. The makeup valve will eliminate cavitation of the motor as the fan slows. The fan slows when flow of oil in the hydraulic fan system is reduced or the flow of oil stops.When the machine is running, valve (4) is controlled by the ECM. When the temperature of the engine coolant is high, the ECM will cause the valve to open. Valve (4) will send a hydraulic oil signal to the pressure and flow compensator (5). The pressure and flow compensator valve is attached to the hydraulic fan pump. The compensator will move the piston in pump (6) that controls the angle of the swashplate. The angle of the swashplate controls the flow of oil to the motor.The return oil from motor (1) is sent to hydraulic oil cooler (10). When the engine is first started and the hydraulic oil is cold, the oil does not easily flow through cooler (10). The pressure of the hydraulic oil overcomes the check valve (hydraulic oil cooler bypass) (9). The check valve is set to open at a pressure of 345 45 kPa (50 7 psi). As the temperature of the oil increases, the resistance of the oil through the hydraulic oil cooler decreases and the check valve will close. When the check valve closes all the oil will pass through the hydraulic oil cooler. The oil flows back to the hydraulic tank. Return oil will pass through filter (8) inside the tank in order to remove any contamination that may be in the hydraulic fan system.