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 648 of 1015

3-103. HORN,

TM 9-2320-272-24-1

THIS TASK COVERS:

a. Removal

b. Installation

INITIAL SETUP:

APPLICABLE MODELS

All

TOOLS

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

MATERIALS/PARTS

Two lockwashers (Appendix D, Item 371)

Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)

TM 9-2320-272-10

TM 9-2320-272-24P

EQUIPMENT CONDITION

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

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

Hood raised and secured (TM 9-2320-272-10).

Battery ground cables disconnected (para. 3-126).

GENERAL SAFETY INSTRUCTIONS

Do not disconnect air lines before draining air

reservoirs.

1.

Disconnect wires (6) and (7) from horn solenoid (6).

WARNING

Do not disconnect air lines before draining air reservoirs. Small

parts under pressure may shoot out with high velocity, causing

injury to personnel.

2.

Disconnect air line (4) from elbow (3).

3.

Remove elbow (3) from horn solenoid (6).

NOTE

Horn solenoid fitting may become disconnected from horn solenoid

during removal. Horn solenoid and fitting are replaced as an

assembly.

4.

Remove horn solenoid (6) from horn (2).

5.

Remove two nuts (10), wire (9), two lockwashers (11), screws (1), and horn (2) from

bracket (13). Discard lockwashers (11).

NOTE

Assistant will help with step 6.

Pull insulation away from inside cab firewall to allow access to

nut.

6.

Remove screw-assembled washer (8), nut (15), washer (14), screw (12), and bracket (13) from

firewall (16).

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