ORGANIZATIONAL TROUBLESHOOTING - continued

TM 9-2320-269-20-1

ORGANIZATIONAL TROUBLESHOOTING - CONTINUED

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

AIR SYSTEM AND BRAKES - CONTINUED

PARKING BRAKE WILL NOT HOLD

WARNING

When performing parking brake maintenance, follow this procedure exactly. The release of trapped air

inside chamber can cause brakes to apply suddenly under extremely high spring tension causing

personnel injury.

Before removing brake hose, if air is trapped, unscrew one to two turns only and allow air to escape. Air is

under pressure and can cause the hose and fitting to break apart causing personnel injury.

Step 1. Check air control valve (1) for proper operation.

a. Start engine (TM 9-2320-269-10), let air pressure build up, and shut off engine (TM 9-

2320-269-10).

b. Pull air control valve (1) to the APPLY position, push to the RELEASE position, and

listen for exhaust.

If air control valve (1) does not exhaust, remove (page 2-526). Clean exhaust port (2),

or replace valve (1) as needed (page 2-526), or notify Direct Support Maintenance.

Step 2. Check inversion valve (3) for proper operation.

a. Have assistant pull air control valve (1) to the APPLY position, then push to the

RELEASE position, and listen for exhaust.

b. If inversion valve (3) does not exhaust, remove (page 2-535). Clean exhaust port (4) or

replace valve (3) as needed (page 2-535), or notify Direct Support Maintenance.

Step 3. Inspect brake hoses (5) for damage.

a. Using diagrams (page 2-608), find brake hoses (5).

b. If hoses (5) are bent or pinched between vehicle components, remove and reroute, or

replace as needed (page 2-567).

If hoses (5) are damaged or collapsed, replace as needed (page 2-567).

2-122

Index