TM-9-2320-272-24-2

TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)

TECHNICAL MANUAL; UNIT, DIRECT SUPPORT, AND GENERAL SUPPORT MAINTENANCE MANUAL; VOLUME 2 OF 4

JUNE 1998
TM-9-2320-272-24-2

  TM-9-2320-272-24-2 - Page 630 of 991

TM 9-2320-272-24-2
3-454. PNEUMATIC CONTROLLER AND RELIEF VALVE MAINTENANCE (Contd)
c. Cleaning and Inspection
1.
For general cleaning instructions, refer to para. 2-14.
2.
For general inspection instructions, refer to para. 2-15.
3.
4.
5.
6.
7.
WARNING
Eyeshields must be worn when cleaning with compressed air.
Compressed air source will not exceed 30 psi (207 kPa). Failure to
do so may result in injury to personnel.
Dry all parts and clear all passages with compressed air.
Inspect base plate (15), cover plate (3), and valve body (2) for cracks and stripped threads.
Replace if damaged.
Inspect relief valve (27) for bends, cracks, and stripped threads. Replace relief valve (27) if bent,
cracked, or threads are stripped.
Inspect wiring harness (6) for broken wires or cracked insulation. Replace wiring harness (6) if
wires are broken or insulation is cracked.
NOTE
Perform step 7 if condition of wiring harness as inspected in step 6
is satisfactory.
Using table 3-2, Electric Connections, check wiring harness (6) for continuity as follows:
a.
Check for continuity between pin A and pin E.
b.
Check for continuity between pin A and pin F.
c.
Check for continuity between pin B and pin D. Replace wiring harness (6) if continuity check a,
b, or c fails.
Table 3-2. Electrical Connections.
PIN
A
B
D
E
F
ELECTRICAL CONNECTIONS
WIRE
Common wire from inflate and deflate valve
Common wire from exhaust valve
Hot wire from exhaust valve
Hot wire from exhaust valve
Hot wire from exhaust valve
LABEL
____
_____
C-CONTROL
D-DEFLATE
S-SUPPLY
1.
Install three new O-rings (18) on valve body ports (19) and five new O-rings (20) on valve body
ports (21).
2.
Apply a thin coat of petrolatum to two new valve cartridges (17) and new valve cartridge (16), and
install valve cartridges (16) and (17) on valve body (2).
3.
Install cover plate (3) on valve body (2) with four screws (4).
4.
Install base plate (15) on valve body (2) with six screws (1).
NOTE
Ensure marked wiring harness ends correspond to C, D, and S
marks on base plate.
5.
Install three new seats (13), new gaskets (12), and wiring harness (6) on cover plate studs (14) with
three nuts (7).
3-1238


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