TM-9-2320-272-10

TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)

TECHNICAL MANUAL; OPERATOR'S MANUAL

SEPTEMBER 2004

CHANGE 2

TM-9-2320-272-10 - Page 343 of 481

TM 9-2320-272-10

2-234

a.

General.

Engine coolant heater is not designed for use while vehicle engine

is operating. This heater preheats engine coolant in preparation for starting at

extremely low temperatures or to maintain engine in standby readiness.

b.

Engine Coolant Heater Operation.

WARNING

Exhaust gases will kill. Do not operate engine coolant heater in

closed area occupied by personnel. Failure to do this will result

in injury or death.

CAUTION

Coolant shutoff valves on engine must remain open at all times

when operating heater. Failure to do this will result in damage

to heater.

(1)

Open coolant shutoff valves (1) and (2).

(2)

Open electric fuel pump shutoff valve located near air cleaner assembly

by turning valve lever (3) one-quarter turn counterclockwise. Open two valves (4)

for M939A2 series vehicles.

2-45. ENGINE COOLANT HEATER KIT