PULLEY 1079575 - Caterpillar

The gauge - sight (hydraulic tank) (22) is located on the right side of the machine next to the cap (hydraulic tank fill) (21). Maintain the oil level in the green area of the sight gauge. Refer to the Operation and Maintenance Manual, "Hydraulic System Oil Level - Check" for more information.Sensor (oil temperature) (23) is located in the implement pump inlet elbow. The sensor is a passive sensor with an operating range of 93° 1°C (199.4° 1.8°F) to 90° 1°C (194.0° 1.8°F).
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(12) Pump (charge)
(13) Pump (implement)
(14) Pump (hydrostatic transmission) Hydraulic oil from the tank (hydraulic) (10) flows into the first section of the pump (implement) (13). The pump (implement) (13) shares a common supply oil with the pump (charge) (12). The gear pumps are driven by a common drive shaft that runs through the pump (hydrostatic transmission) (14). The pump (charge) (12) supplies oil to the hydraulic system and to the hydrostatic system.
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(20) Motor (demand fan)
(24) (SOS) scheduled oil sample port
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(20) Motor (demand fan) Hydraulic oil for the motor (demand fan) (20) is supplied by the pump (charge) (12). Hydraulic oil from the tank (hydraulic) (10) flows to the front section of the pump (implement) (13). The oil flows from the pump (charge) (12) to the motor (demand fan) (20). The flow of oil through the gear motor turns the fan that cools the hydraulic oil that passes through the cooler (11). Tap (24) is the "SOS" tap for the hydraulic system.The fan motor will rotate in direct relation to the amount of hydraulic oil flow until the hydraulic oil pressure reaches the setting for the relief valve (electrohydraulic proportional) (26). The relief valve (electrohydraulic proportional) allows the excess oil to bypass the gear motor. The relief valve (electrohydraulic proportional) is not a mechanical type of valve. The relief valve (electrohydraulic proportional) is controlled by the ECM based on input by the engine coolant temperature sensor and the hydraulic oil temperature sensor. Use the Caterpillar Electronic Technician software in order to calibrate the demand fan. For more information on the calibration of the demand fan, refer to Hydraulic System Testing and Adjusting, "Gear Motor (fan) - Test".
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(19) Filter (hydraulic oil)
(27) Switch (pressure) Hydraulic oil then flows out of the motor (demand fan) (20) and into the filter (hydraulic oil) (19). The filter (hydraulic oil) is located in the engine compartment. The filter (hydraulic oil) is a 5 micron filter. The filter (hydraulic oil) removes any particles that could damage the piston pump.Within the pump (hydrostatic transmission) (14), oil flows across the relief valve (main) (31) which regulates charge pressure. Oil also becomes available to replenish drive loop losses via the four relief valve (cross over) (30). Drive loop losses are primarily the result of the flushing circuits in the piston motor (hydrostatic left side) (15) and piston motor (hydrostatic right side) (17). The flushing circuits are designed to ensure a supply of cooled & filtered oil is continually supplied