PEDAL AS 4840878 - Caterpillar

824G Wheel Tractor and 825G Soil Compactor
Illustration 1 g00661085
(1) Fan (2) Fan motor (3) Hydraulic pump for the fan motor (4) Relief valve (5) Hydraulic oil cooler (6) Check valve (7) Case drain line (8) Hydraulic oil tank
Illustration 2 g00661159
(3) Fan drive pump (4) Discharge port for the relief valve (9) Pump discharge port (10) Suction port for the fan pump (11) Implement pumpThese machines share the same type of fan drive system. Fan pump (3) withdraws oil from hydraulic oil tank (8). Oil flows from pump (3) to fan motor (2). The fan motor turns the fan for the cooling system. Oil from the fan motor is sent through a hydraulic oil cooler (5). A check valve (6) is provided in order to bypass the cooler if the cooler is clogged. Oil flows from the oil cooler back to the hydraulic oil tank.Relief valve (4) prevents the system pressure from reaching excessive levels. The relief valve pressure is set to approximately 15200 kPa (2204.6 psi). 826G Landfill Compactor
Illustration 3 g00661341
(1) Fan blade (2) Fan motor (3) Case drain line (4) Crossover relief valve (5) Solenoid valve (6) Fan pump (7) Hydraulic oil cooler (8) Bypass check valve (9) Relief valve (10) Hydraulic oil tankThe fan drive system for the 826G Landfill Compactor is equipped with a reversible solenoid valve. The valve (5) is shifted by a solenoid. The valve is shifted by the solenoid automatically in 30 minute intervals. The valve is shifted for 20 seconds. The shifting of valve (5) causes the direction of fan motor (2) to change. The fan (1) will reverse in order to blow debris from the radiator guard. The valve will return to the normal position after 20 seconds.Fan pump (6) withdraws oil from the hydraulic oil tank. Oil flows through valve (5) to fan motor (2). The fan motor turns fan (1). Crossover relief valve (4) protects the system from excessive pressure spikes as the fan reverses. Oil flows through valve (5) to cooler (7). The cooled oil is returned to the hydraulic oil tank. A bypass check valve (8) is provided if the cooler is clogged.Relief valve (9) prevents the system pressure from exceeding 15200 kPa (2204.6 psi).