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 - Page 484 of 991

TM 9-2320-272-24-2

3-425. HAND AIRBRAKE TRACTOR PROTECTION VALVE REPLACEMENT

THIS TASK COVERS:

a. Removal

b. Installation

INITIAL SETUP:

APPLICABLE MODELS

All (except M931/A1/A2, M932/A1/A2,

REFERENCES (TM)

M933/A1/A2, M936/A1/A2)

TOOLS

TM 9-2320-272- 10

TM 9-2320-272-24P

EQUIPMENT CONDITlON

• Parking brake set (TM 9-2320-272-10).

• Air reservoirs drained (TM 9-2320-272-10).

General mechanic’s tool kit (Appendix E, Item 1)

MATERIALS/PARTS

Two locknuts (Appendix D, Item 299)

Antiseize tape (Appendix C, Item 72)

GENERAL SAFETY INSTRUCTIONS

Do not disconnect air lines before draining air

reservoirs.

a. Removal

WARNING

Do not disconnect air lines before draining air reservoirs. Small

parts under pressure may shoot out with high velocity, causing

injury to personnel.

NOTE

Tag air lines for installation.

1.

Disconnect four air lines (2) from elbows (1).

2.

Remove four elbows (1) from valve (3).

3.

Remove two locknuts (6), valve (3), and two screws (5) from frame rail (4). Discard locknuts (6).

b. Installation

1.

Install valve (3) on frame rail (4) with two screws (5) and new locknuts (6).

NOTE

Wrap all male pipe threads with antiseize tape before installation.

2.

Install four elbows (1) on valve (3).

3.

Connect four air lines (2) to elbows (1).

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