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