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MGM SERVICE AND PARKING BRAKE
Releasing Spring Brake Manually:
If air pressure fails in the piston chamber, the power spring applies
the brakes and, unless pressure can be reestablished, the service brakes must be released as follows in order to
move the coach.
WARNING: Do not release spring brake until coach is secured by wheel chocks or tow vehicle. Failure to
do so may result in bodily injury or property damage.
Remove the release stud tool and
nut from the carrying pocket on the
brake chamber assembly. Remove the
access plug from the end of the spring
chamber. Insert the release stud
through the opening in the chamber
and into the spring pressure plate.
Turn the release stud one-fourth (1/
4) turn to engage the stud tangs with
the slot in the pressure plate. Keep the
stud engaged and install the nut on
the release stud. Tighten the nut until
the spring is fully caged and the
brakes are released. Do not loosen or
remove the release stud and nut un-
less the brake chamber is completely
assembled and is securely clamped.
When air pressure is restored, remove
the release stud and install in carry-
ing pocket.
DOOR/BRAKE INTERLOCK
(If so equipped)
The door/brake interlock includes a 12 VDC power unit with integral pressure switches, a single actuator
(displacing 2.9 cubic inches of system fluid) and an electronic control module. The operator interface of the
electronic control module consist of an on/off switch, audible alarm and amber and green system indicator
lights located at the switch panel to the left of the driver. The maximum system pressure control is factory set.
The door/brake interlock has an added feature in that it can also be used as a supplemental brake locking
device.
The door/brake interlock will repressurize brake system and sound audible alarm if pressure drops be-
low required system pressure. If audible alarm sounds repeatedly, a small leak and/or air is present in the
door/brake interlock or the vehicle brake system.
PRINCIPLES OF OPERATION
The door/brake interlock is armed when vehicle ignition is on. A switch contact closure will activate the
door/brake interlock when door is opened. At that point the door/brake interlock utilizes existing service
brake system to apply brakes.
LOCK SYSTEM
The door/brake interlock is also a SUPPLEMENTAL safety device and is NOT to be used in place of
original equipment parking brake. When used with existing vehicle parking brake the door/brake interlock
BRAKE
RELEASE
CARRYING
NUT
TANGS
RELEASE
STUD TOOL
NUT
RELEASE
STUD
SPRING
CHAMBER
