TM 5-4930-218-14
REPAIR OF BRAKE RELAY VALVE
the trailer provide a supply of air for quick ap-
8-1. Description
plication.
b. During normal braking operation of relay valve,
valve and emergency relay valve. The brake valve
towing vehicle supply air enters the valve through
section is used in combination with the air brake
the emergency port and is directed into the reser-
treadle valve on the towing vehicle for normal
voirs. The air is prevented from reversing its direc-
braking of vehicle and trailer. It automatically ap-
tion of flow by a check valve (30, fig. 8-1). It also
plies the trailer brakes in the event the trailer breaks
keeps inlet valve (20) closed.
away from the towing vehicle. The air reservoirs on
