5.2.11 Air Chamber/Spring Brake - Midland SIDE DUMP GRAVEL TRAILER Operator's Manual

5.2.11 AIR CHAMBER/SPRING BRAKE

Air chambers mounted on the axle use the air supply/
pressure from the tractor to apply the service
brakes for stopping the vehicle. In addition this
air chamber may be equipped with a spring brake
that applies the brake when the service side of
the brake loses air. The spring brake side of the
system is used as a parking and/or emergency
brake if the service side fails.
Spring brakes should not be serviced by anyone
in the field unless they have been trained in the
proper procedure. Do not open the air chamber
unless the spring is caged or locked out. Do not
work on the brakes unless the springs are caged
or locked out. Do not move the trailer if the
springs are caged.
When caging or locking out the spring brakes,
follow this procedure:
1. Place chocks in front of and behind the trailer
wheels.
2. Insert the release bolt, stored on the side of
the chamber, into the hole in the head and
through the piston.
3. Turn the release bolt clockwise until it stops
and locks.
4. Pull release bolt out as far as possible and
run the nut down while holding the bolt in
place.
5. Use a wrench to turn the release bolt nut
clockwise until the bolt extends about 3
inches.
6. Be sure the release bolt is locked in position.
7. Always release the spring before placing the
trailer back in service.
70
Fig. 61 SPRING BRAKE
Schematic
Axle