TM-9-2320-272-24-1

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

TECHNICAL MANUAL; UNIT, DIRECT SUPPORT, AND GENERAL SUPPORT MAINTENANCE MANUAL; VOLUME 1 OF 4

JUNE 1998

TM-9-2320-272-24-1 - Page 966 of 1015

3-212. DOUBLECHECK

TM 9-2320-272-24-1

THIS TASK COVERS:

a. Removal

b. Installation

APPLICABLE

MODELS

REFERENCES (TM)

All

TM 9-2320-272-10

TOOLS

TM 9-2320-272-24P

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

MATERIALS/PARTS

Locknut (Appendix D, Item 299)

Antiseize tape (Appendix C, Item 72)

EQUIPMENT CONDITION

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

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

GENERAL SAFETY INSTRUCTIONS

Do not disconnect air lines before draining air

reservoirs.

Do not disconnect air lines before draining air reservoirs. Small

parts under pressure may shoot out with high velocity, causing

injury to personnel.

NOTE

Doublecheck valve No. 1 is located inside the front left frame

rail and left of the front axle differential.

Tag air lines for installation.

1.

Disconnect line (1) from doublecheck valve No. 1 adapter (2).

2.

Disconnect line (12) from valve adapter (11).

3.

Disconnect line (9) from tee (10).

4.

Remove tee (10) from doublecheck valve No. (3).

5.

Disconnect line (5) from valve adapter (7).

6.

Remove locknut (8), screw (4), and doublecheck valve No. 1 (3) from frame rail (6). Discard locknut (8).

NOTE

If new doublecheck valve is being installed, use fittings from old

doublecheck valve.

Wrap all male pipe threads with antiseize tape before

installation.

1.

Position doublecheck valve No. 1 (3) against frame rail (6) and install with screw (4) and new locknut (8).

2.

Connect line (5) to valve adapter (7).

3.

Install tee (10) on doublecheck valve No. 1 (3).

4.

Connect line (9) to tee (10).

5.

Connect line (12) to valve adapter (11).

6.

Connect line (1) to doublecheck valve No. 1 adapter (2).

3-602