Radiator Cooling Fan: Description and Operation

Fig. 1 Cooling Fan System Components:

The electronically controlled hydraulic cooling fan system consists of a belt-driven hydraulic pump, a pump solenoid valve, a hydraulic fan motor and an electronic system controller (ECU), Fig. 1. The cooling fan processor (controller) determines hydraulic pressure by monitoring engine and air conditioner operation. A processor-controlled solenoid valve regulates oil flow from the integrated power steering/hydraulic pump to the fan motor. After leaving the fan motor, heated oil is then cooled by an oil cooler before returning to the power steering pump reservoir.