MEGA Corp. MSC-OPS-1 - Manual (Page 26)

MSC/MST-OPS-1
31 Dec 2013
SECTION 2
System Description
2-17
pneumatic pressure from the pneumatic manifold to
be routed to the brake pod. This pressure increase
will eventually overcome the brake pod coil spring
and retract the brake pod cylinder rod end attached
to the brake pod releasing the brakes. As pressure
increases above allowable limits, the parking brake
pressure switch will turn off the parking brake
warning light in the tractor cab once pressure is
above allowable limits.
Service Brake
The service brake is applied by pressing down on the
service brake pedal in the tractor cab. Pressing down
on the pedal will send a pneumatic pressure signal to
the service brake relay valve mounted on the rear
bogie. The sent signal will release pneumatic
pressure from the brake pod chamber allowing the
pod coil spring to extend the rod end and apply
service brakes.
The service brake is released by releasing the brake
pedal. Once the pedal released a pneumatic signal is
received by the brake relay to increase air pressure to
the brake pod. As pneumatic pressure increases the
force of the brake pod coil spring is overcome and
the service brake is released.
Emergency Brake
The emergency brake theory of operation is the same
as the parking brake except for the means of
activation. Activation is accomplished by using the
emergency brake foot switch located on the floor of
the tractor cab just left of the service brake pedal.