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 149 of 481

2-50

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

16

Before

Trailer

Brakes

DRIVER

a.

Couple and uncouple tractor

(3) and trailer (1) to determine if

fifth wheel (2) and locking mecha-

nism (4) are working properly

(para. 2-26).

NOTE

Perform this check with the

trailer empty and the trailer

loaded after the tractor/trailer

are coupled.

b.

Check for air leaks at the

intervehicular connecting hoses,

relay valve, and air reservoirs

(para. 3-12).

c.

Using trailer brake/Johnnie

bar (5) only, apply trailer brakes

and attempt to move tractor/trailer

combination.

a.

Tractor (3)

and trailer (1) will

not couple prop-

erly or locking

mechanism (4)

fails to hold.

b.

Any air leaks

are present. Coupl-

ing or uncoupling

action faulty.

c.

Brakes fail

to hold tractor/

trailer combina-

tion from moving.

5

1

2

3

4