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 321 of 481

TM 9-2320-272-10

2-212

CAUTION

If engine temperature continues to rise or does not drop after

two minutes of idling, shut down engine and refer to trouble-

shooting table 3-1.

(b)

Observe coolant temperature gauge (1), engine oil pressure gauge (3),

and transmission oil temperature gauge (2) for signs that engine or transmission is

steadily cooling.

(c)

Shut off when engine coolant temperature gauge (1) reaches normal

operating temperature of 175°-200°F (79°-93 °C).

(d)

Perform troubleshooting procedures as listed in table 3-1.

WARNING

Extreme care should be taken when removing surge tank filler

cap if coolant temperature gauge reads above 175°F (79°C).

Steam or hot coolant under pressure will cause injury.

(e)

Place a thick cloth over surge tank filler cap (4). Carefully turn cap (4)

counterclockwise to first stop to allow pressure to escape.

(f)

Remove cap (4) when cooling system pressure is vented and check

coolant level. Surge tank should be filled approximately to bottom of filler neck.

(g)

Add engine coolant as required. Install surge tank filler cap (4) after

filling and start engine (para. 2-12).

(h)

Proceed with operation. Report any overheating to unit maintenance

upon completion of operation.

d.

Stopping or Parking.

(1)

Park vehicle in a sheltered area, out of sun, if possible.

(2)

Check batteries after operation and service, as required.

2-34. OPERATING IN EXTREME HEAT (Contd)