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 203 of 481

TM 9-2320-272-10

2-102

(1)

Noisy engine and/or excessive engine vibration.

(2)

Oil pressure does not register, or suddenly drops to less than 15 psi

(103 kPa) on M939A1 series; 10 psi (69 kPa) on M939A2 series, as indicated by engine

oil pressure gauge (6).

(3)

Sudden increase in coolant temperature beyond normal operating

temperature, 175°-200°F (79°-93°C), as indicated by engine coolant temperature

gauge (5).

(4)

Engine continues to run after ignition switch (1) and battery switch (3)

are turned to OFF positions.

q.

After an emergency shutdown, the engine will not restart until unit

maintenance resets the fuel shutoff valve. On M939A2 series vehicles, position

EMERGENCY ENGINE STOP control (7) to reset.

r.

Turn vehicle light switch (9) to desired position (para. 2-18).

a.

Perform steps a. through k. in paragraph 2-12.

b.

Press ether start switch (8) during cranking. Allow three seconds for ether to

discharge into system after releasing switch (8).

CAUTION

Do not operate starter continuously for more than 10 seconds at a

time or with headlights on. Wait 10-15 seconds between periods of

starter operation.

NOTE

If engine cranks but will not start, turn battery switch to OFF

position. See troubleshooting, malfunction 3.

c.

Release engine ignition switch (1) after engine starts.

2-13. COLD WEATHER STARTING (BELOW +32°F) (O°C)

2-12. STARTING THE ENGINE (ABOVE +32°F) (O°C) (Contd)