SERVICE BRAKES ON ALL AXLES DO NOT APPLY OR APPLY SLOWLY. (Cont) -725550567

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.

PRESSURE TEST

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

(2) Disconnect air hose 2639 from front

brake relay valve.

(3) Connect air hose 2639 to 0-160 psi

(1103 kPa) pressure gage.

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

(5) Push in trailer charge valve in

(6) While assistant fully applies brake

pedal, observe pressure gage.

(a) If 60 5 psi (414 34 kPa) is

not measured at air hose 2639,

perform Steps (7) through (11)

below and replace quick release

(b) If 60 5 psi (414 34 kPa) is

measured at air hose 2639,

quick release valve is OK.

(7) Release brake pedal.

(8) Pull out trailer charge valve in truck.

(9) Turn OFF ENGINE switch.

(10) Disconnect air hose 2639 from

pressure gage.

(11) Connect air hose 2639 to front

brake relay valve.

VERIFY REPAIR

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

(2) Push in trailer charge valve in

(3) While assistant fully applies brake

pedal, observe brake operation.

(a) If brakes do not operate correctly,

fault not corrected. Perform

Steps (4) and (5) below and notify

DS Maintenance.

(b) If brakes operate correctly,

fault corrected.

(4) Release brake pedal.

(5) Pull out trailer charge valve in truck.

(6) Turn OFF ENGINE switch.