ALL PARKING BRAKES DO NOT RELEASE. (Cont) -725550543

TM 9-2330-385-14

If air lines are disconnected when they are under 125 5 psi (862 34 kPa), they can whip around and

cause personal injury. Care should be exercised when disconnecting an air hose that is thought to be

under pressure.

NOTE

Trailer air system pressure must be 125

5 psi (862 34 kPa) to begin

troubleshooting the brake system. If the

air system pressure cannot be maintained,

refer to Air System Troubleshooting.

Air lines and valves listed in this

troubleshooting procedure are illustrated

and located in FO-2.

PRESSURE TEST

(1) Drain trailer air system (Para 2-21).

(2) Disconnect air hose 2022 from right

front brake chamber.

(3) Connect air hose 2022 to 0-160 psi

(1103 kPa) pressure gage.

(4) Start engine (TM 9-2320-364-10).

(5) While assistant pushes in trailer

charge valve in truck, observe

pressure gage (Para 2-22).

(a) If 125 5 psi (862 34 kPa) is not

measured, perform Steps (6)

through (9) below and replace

multifunction valve (Para 4-52).

(b) If 125 5 psi (862 34 kPa) is

measured, multifunction valve

is OK.

(6) Pull out trailer charge valve in truck.

(7) Turn OFF ENGINE switch.

(8) Disconnect air hose 2022 from

pressure gage.

(9) Connect air hose 2022 to right front

brake chamber.