SERVICE BRAKE(S) ON ONE AXLE DO NOT APPLY OR APPLY SLOWLY. (Cont) -725550571

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

The relay valve test listed below applies to all

brake relay valves.

PRESSURE TEST

(1) Drain air from trailer air system

(2) Disconnect air hose 2545 from right

front brake chamber.

(3) Connect 0 to 160 psi (1103 kPa)

pressure gage to air hose 2545.

(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 valve output pressure is less

than 60 5 psi (414 34 kPa),

perform Steps (7) through (11)

below and replace relay valve

(b) If valve output pressure is 65 psi

(448 kPa) or more and continues

to increase, perform Steps (7)

through (11) below and replace

multifunction valve (Para 4-52).

60 5 psi (414 34 kPa), relay

valve is OK.

(7) Release brake pedal.

(8) Pull out trailer charge valve in truck.

(9) Turn OFF ENGINE switch.

(10) Disconnect air hose 2545 from

pressure gage.

(11) Connect air hose 2545 to right front

brake chamber.