TM-9-2320-272-24-4

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

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

JUNE 1998

TM-9-2320-272-24-4 - Page 624 of 836

5-105. DUMP

TM 9-2320-272-24-4

8.

Remove cotter pin (12) and slotted nut (13) from piston rod (8) and piston (9). Discard cotter pin (12).

9.

Slide piston (9) off piston rod (8).

10.

Remove three piston rings (11) from piston grooves (10).

NOTE

Tag bypass plugs, springs, and check balls for installation.

11.

Remove three bypass plugs (6), springs (5), and check balls (4) from hoist cylinder housing (7).

12.

Remove orifice plug cover (1) and orifice plug (2) from cylinder base (3).

NOTE

Use clean lint-free cloth to wipe parts clean. After parts are

cleaned and inspected, coat them with a light film of clean

hydraulic oil.

1.

Wipe check balls (4) clean and inspect. Replace if scratched, chipped, or marked.

2.

Wipe piston (9) clean and inspect. Replace if cracked or broken.

3.

Measure outside diameter of piston (9). If outside diameter is less than 5.236 in. (132.994 mm),

replace piston (9).

4.

Wipe piston rod (8) clean and inspect. Replace if scratched, chipped, or scored.

5.

Measure outside diameter of piston rod (8). If outside diameter is less than 1.994 in. (50.648 mm),

replace piston rod (8).

5-618