Page 19
3.2.1.3
The relay valve should not have a continuous flow of air from the exhaust port except
immediately after a brake release. If air continues to discharge, it could be a malfunction
of the exhaust valve, or the “O” ring seal on the push rod of the spring brake chamber is
bad and is allowing air to be discharged through the service chamber and out the relay
valve exhaust port. To check this, the system must be charged, parking brakes off,
service brakes off, then disconnect the service hose at service brake chamber. If air is
discharging from service port, the “O” ring is bad. If air is escaping from service brake
hose, the exhaust valve is malfunctioning. Repair “O” ring seal or exhaust valve or
replace complete part.
Caging tools are supplied with trailer and are on a bracket attached to the trailer frame
near the spring brake chamber, or on the chamber. For vendor files on brake chambers,
see below.
DI-PRO Brake Chambers
MGM Brake Chambers
Air reservoir tanks should be drained daily to remove moisture and other contaminants.
More than once a day may be necessary in the winter when the humidity is high.
Parking brake application will begin after air pressure falls below 55 psi and application
increases as air pressure drops.
Parking brakes will start releasing after the system pressure reaches 55 psi and should
be fully released when pressure reaches 70 psi.
Parking brakes may be disengaged in an emergency by manually caging the spring in
each spring brake chamber using the tool provided. Do not operate the vehicle except in
emergency as there are no emergency brakes available when the spring brakes are
caged.
DO NOT REMOVE CLAMP RING FROM SPRING BRAKE CHAMBE
R
UNLESS SPRING IS PROPERLY CAGED! IF NOT CAGED, THE
INTERNAL SPRING WILL BE RELEASED WITH EXPLOSIVE
F
O
R
C
E AND MAY
C
A
US
E
S
EVERE B
O
DILY IN
JU
RY!
DO NOT OPERATE TRAILER WITH SPRING BRAKES CAGED, O
R
IN ANY WAY DISABLED, EXCEPT IN AN EMERGENCY SITUATION!
WHEN SPRING BRAKES ARE CAGED, THERE ARE NO
EMER
G
EN
C
Y BRAKE
S
AVAILABLE.
DO NOT ATTEMPT TO DISASSEMBLE
SPRING-BRAKE. THIS CAN RESULT IN FATAL INJURY.
LINK TO VENDOR FILE
LINK TO VENDOR FILE
