SENSOR GP-POSITION 2661480 - Caterpillar

Illustration 4 g00909441
Sectional View of the Makeup Valve (1) Fan motor inlet. (3) Fan motor outlet. (4) Check valve.Note: Illustration 4 shows the makeup valve during normal operation of the motor.
Illustration 5 g00909550
Sectional View of the Makeup Valve (1) Fan motor inlet. (3) Fan motor outlet. (4) Check valve.Note: Illustration 5 shows the movement of check valve (4) as the fan motor is going into shutdown.The piston motor is equipped with a makeup valve. The makeup valve will allow oil that is exiting the hydraulic motor to return to the motor inlet during the reduction of flow from the pump or a complete shutdown. If the pressure at outlet line (3) is higher than the pressure in inlet line (1), oil will open check valve (4). The oil will flow through check valve (4) and back to inlet (1). The makeup valve eliminates cavitation of the fan motor (3) during reduced oil flow. The return oil from hydraulic fan motor (2) is used as makeup oil in order to prevent a vacuum condition in inlet (1) of hydraulic fan motor (2). This condition happens when the fan slows and/or the fan stops. When the hydraulic fan pump slows down, the supply of oil to fan motor (2) is reduced. Fan motor (2) will continue to rotate because the resistance of the air that is being pushed through the radiator is not strong enough to stop the fan blade from turning fan motor (2). Continued rotation of fan motor (2) creates a vacuum in the makeup valve. The vacuum causes a lower pressure in fan motor inlet (1). The combined force of lower pressure in fan motor inlet (1) and the force of spring is below than the force of the pressure of the return oil in fan motor outlet (3). Check valve (4) will open. When check valve (4) is open, the return oil will flow back through the makeup valve. The return oil re-enters the fan motor inlet (1). This makeup oil circuit eliminates cavitation in hydraulic fan motor (2). The same process occurs when the fan motor is shut down.Piston Motor (Automatic Reversing Fan)
Illustration 6 g00977431
Sectional View of the Piston Motor (1) Case drain. (2) Head. (3) Drive shaft. (4) Swashplate. (5) Shoe. (6) Rotating plate. (7) Frame. (8) Piston assembly. (9) Barrel. (10) Spring. (11) Valve plate. (12) Locating pin.The fixed displacement piston motor is a reversible motor. The port with oil flow will determine the direction of rotation for the motor. If the pump supply oil flows into port A, the motor will rotate in the counterclockwise direction. The return oil will flow out of the motor through port B. If the pump supply oil flows into port B, the motor will rotate in the clockwise direction. The return oil will flow out of the motor through port A.In the fixed displacement piston motor, there are both the rotating components and the stationary components. The rotating components are the drive shaft (3), shoe (5), rotating plate