TM-9-2320-272-24-3
TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)
TECHNICAL MANUAL; UNIT, DIRECT SUPPORT, AND GENERAL SUPPORT MAINTENANCE MANUAL; VOLUME 3 OF 4
JUNE 1998
TM-9-2320-272-24-3 - Page 390 of 799
TM 9-2320-272-24-3
4-121. POWER STEERING ASSIST CYLINDER REPAIR
THIS TASK COVERS:
a. Disassembly
b. Cleaning, Inspection, and Repair
c. Assembly
INITIAL SETUP
APPLICATION MODELS
REFERENCES (TM)
All
LO 9-2320-272-12
TOOLS
TM 9-2320-272-24P
General mechanic’s tool kit (Appendix E, Item 1)
EQUIPMENT CONDITION
Vise
Power steering assist cylinder removed (para. 3-233).
MATERIALS/PARTS
Seal (Appendix D, Item 628)
Locknut (Appendix D, Item 332)
Packing ring (Appendix D, Item 513)
Lubricating oil (Appendix C, Item 48)
Drycleaning solvent (Appendix C, Item 71)
GENERAL SAFETY INSTRUCTIONS
Keep fire extinguisher nearby when using
drycleaning solvent.
WARNING
Drycleaning solvent is flammable and toxic. Do not use near an
open flame and always have a fire extinguisher nearby when
solvents are used. Use only in well-ventilated places, wear
protective clothing, and dispose of cleaning rags in approved
container. Failure to do this may result in injury to personnel
and/or damage to equipment.
1.
Thoroughly clean power steering assist cylinder (7) with drycleaning solvent.
NOTE
Have drainage container ready to catch oil.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Holding oil ports down, push piston rod (15) in and out to remove oil from cylinder (7).
Clamp steering assist cylinder (7) in vise.
Remove three screw-assembled washers (4), retainer (3), seal (2), and end plate (1) from top of
steering assist cylinder (7).
Pushing cylinder gland (6) in, remove backup ring (5) from cylinder (7).
Remove cylinder gland (6), piston (11), and piston rod (15) as an assembly from cylinder (7).
Remove locknut (14) from piston rod (15). Discard locknut (14).
Turn piston (11) counterclockwise and remove from rod (15).
Remove cylinder gland (6) from rod (15).
12.
13.
4-654
Remove seal (13) and packing ring (12) from piston (11). Discard seal (13) and packing ring (12).
Remove snapring (22), retaining ring (21), oil seal (20), retaining ring (19), retaining ring (18), gland
backup ring (17), and gland O-ring (16) from gland (6). Discard oil seal (20), gland backup ring (17),
and gland O-ring (16).
Remove O-ring (24) and backup ring (23) from cylinder gland (6). Discard O-ring (24) and backup
ring (23).
Remove plug (10), two ball sockets (9), and spring (8) from steering assist cylinder (7).
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