COOLING SYSTEM - continued - TM-9-2320-391-100087

TM 9-2320-391-10

M1078A1 SERIES THEORY OF OPERATION -

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Continued

COOLING SYSTEM - Continued

3. A radiator overflow tank is provided to allow for expansion of the coolant. The

radiator overflow tank also serves as the point where new coolant is introduced into

the cooling system. The radiator overflow tank has two sight glasses. The upper sight

glass indicates the coolant level to fill to with the engine shut down. If coolant is not

visible in the lower sight glass, do not operate the vehicle.

4. The engine fan, with pneumatic fan clutch, is activated by the water temperature

sensor. Whenever this sensor detects a high engine temperature condition, air

pressure is removed from the fan clutch and the engine fan is engaged.

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