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 147 of 481

2-48

Change 2

Table 2-3. Preventive Maintenance Checks and Services for Models M939/A1/A2 (Contd).

ITEM

NO.

INTERVAL

ITEM TO

CHECK/

SERVICE

NOT FULLY

MISSION

CAPABLE IF:

TM 9-2320-272-10

LOCATION

CREWMEMBER

PROCEDURE

14

Before

Air

Dryer

DRIVER

NOTE

• Air dryer references apply

only to M939A2 series

vehicles and those vehicles

with air dryer kit or ABS kit.

• Moisture ejector valve on

M939A2 series vehicles

without ABS kit must

exceed 120 psi (827 kPa) for

air to expel.

a.

Start engine and idle at 550-

650 rpm (para. 2-12).

b.

Listen for unusual noises or

vibrations.

NOTE

If unable to hear moisture

ejector valve expulsion, set

emergency brake, shift to

park, and check right side of

vehicle.

DRIVER

c.

Check for proper operation,

listening for moisture ejector valve

(1) to expel air.

WARNING

Use care when checking

heater; it may be hot to touch

and cause injury to personnel.

d.

Touch heater (2). It should be

warm if operating properly and

area temperature is below 40°F

(2°C).

a.

Engine is

inoperable.

b.

Engine has

unusual noises or

vibrations.

c.

Ejector valve

is inoperable.

d.

Heater is

inoperable.

ABS AIR DRYER

2

1

1

2

1

2