Truck Parts And Their Functions

Item	Sample Picture	Function
Fan Clutch		A viscous fan clutch senses the air temperature behind the radiator core, and engages or disengages the fan depending on that temperature. It spins the fan when more cooling airflow is needed, and disengages it when the radiator is sufficiently cooled. An electromagnetic fan clutch is an on/off-style engine cooling fan clutch. The fan clutch is electrically operated, and is not connected to the vehicle's air system.
Radiator		A radiator helps to eliminate excess heat from the engine. It is part of the engine's cooling system, which also includes a liquid coolant, hoses to circulate the coolant, a fan, and a thermostat that monitors the coolant temperature.
Surge tank		The surge tank provides storage space for reserve coolant, expansion space for heated coolant, and deaeration space. When coolant in the radiator runs low, reserve coolant stored in the surge tank flows from the tank through the fill hose to the water pump. As the coolant heats and expands beyond radiator capacity, excess coolant travels back through the fill hose from the water pump to the surge tank. Any air trapped in the engine block or radiator rises to the top of the engine or radiator and escapes through the vent hoses to the surge tank. The low coolant level sensor in the surge tank warns the driver when coolant is running low.