TM-9-2320-280-20 HMMWV Technical Manual Unit Maintenance Volume 1 Download
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TM 9-2320-280-20-1 1-20. COOLING SYSTEM OPERATION (Cont'd) FAN - Pulls outside air through radiator to remove heat from coolant. HYDRAULIC CONTROL VALVE - Directs hydraulic fluid to provide required pressure to actuate fan clutch as required by engine temperature. Hydraulic pressure supplied by power steering pump. TIME DELAY MODULE - Sends delayed signal to fan clutch solenoid for delay of fan actuation to provide needed horsepower for engine acceleration. FAN CLUTCH SOLENOID - Actuates hydraulic control valve as required by coolant temperature. WATER PUMP - Driven by V-belts provides circulation of coolant through cooling system. FAN CLUTCH - Hydraulically actuated by pressure from hydraulic control valve to control operation of fan. Hydraulic pressure supplied by power steering pump. DRAINCOCK - Draining point for radiator and cooling system. RADIATOR SHROUD - Permits a greater concentration of air to be pulled through the radiator. 1-39