THEORY OF OPERATION - continued - TM-9-2320-361-24-10072

TM 9-2320-361-24-1

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THEORY OF OPERATION (Contd)

COOLING SYSTEM

Cooling System Operation: The engine cooling system is a pressurized, thermostatically controlled

system consisting of a radiator, thermostat, water pump, fan, and hoses. The major components of the

cooling system are as follows:

A ENGINE OIL COOLER Removes excess heat from engine oil.

B ENGINE TEMPERATURE SENDING UNIT Detects temperature of engine coolant and sends an

electrical signal to temperature gauge on instrument panel.

THERMOSTAT Shuts off coolant flow to radiator until temperature reaches 180F (82C). Coolant

is then allowed to flow to the radiator through the upper radiator hose.

RADIATOR FILLER CAP When removed, filler neck serves as filling point for cooling system.

When installed, cap allows cooling system to be pressurized.

RADIATOR Directs coolant through a series of fins or baffles so outside air can remove excess

heat from coolant.

UPPER RADIATOR HOSE Directs coolant from engine block to radiator when thermostat opens.

FAN Pulls outside air through radiator to remove excess heat from coolant.

WATER PUMP Circulates coolant through cooling system.

LOWER RADIATOR HOSE Directs coolant from radiator back to engine block.

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