Bendix Commercial Vehicle Systems PIGGYBACK SPRING BRAKE - Manual (Page 5)

5
FIGURE 5 - PIGGYBACK CHAMBER
• Do not remove the Piggyback Spring Chamber
Clamps.
1. Mechanically release the old piggyback spring brake by
following the original manufacturer’s instructions.
2. Ensure air pressure is removed from all air reservoirs
before removing the air hoses or working on the
spring brake.
3. Remove air hoses from the Piggyback spring brake
chamber. Be sure to mark both hoses to ensure
proper reinstallation.
4. Clamp a pair of vise grips around the service pushrod
touching the non-pressure housing. This cages the
service return spring.
5. Remove the clamp nuts and service clamp assembly
and carefully remove the old piggyback chamber.
INSTALLING THE BENDIX PIGGYBACK SPRING
BRAKE CHAMBER
1. Visually inspect the service diaphragm for excessive wear,
damage or cracks. Replace if needed. To replace the
service diaphragm, perform the steps outlined in
"Replacing the Service Diaphragm".
2. Line up the new piggyback spring brake chamber, the
service diaphragm, and the non-pressure housing,
ensuring that they are centered.
3. Reassemble the service clamp assembly. Ensure all
parts are seated properly and remain centered.
4. Torque the clamp nuts to 25 ft/lbs. Remove the vise grips
from the service push rod.
5. Reconnect the emergency air line to the emergency
porthole and reconnect the service air line to the
service porthole.
6. Pressurize the service half by putting air into the service
port. Do not exceed 120 psig. Test for leaks around the
clamps. No leaks are acceptable.
7. Uncage the main spring and return the release tool into
the release tool side pocket.
8. Replace the dust cap in the keyhole.
WARNING!
Check for proper service and emergency operation
after servicing any part of the brake chamber(s). Check
the brake adjustment if the combination spring brake
was removed/installed (Follow vehicle manufacturer’s
instructions to adjust the brakes).
REMOVAL AND INSTALLATION OF THE
COMBINATION SPRING BRAKE
WARNING!
Do not mechanically release (cage) the spring if there
is any structural damage to the piggyback spring brake
chamber. Caging the spring in such a chamber may
cause serious injury or death. Replace the complete
assembly.
REMOVAL:
1. Mechanically release (cage) the old piggyback spring
brake chamber by following the original manufacturer’s
instructions.
2. Ensure air pressure is removed from all air reservoirs
before removing the air hoses or working on the spring
brake.
3. Remove air hoses from the piggyback spring brake
chamber. Be sure to mark both hoses to ensure proper
reinstallation.
4. Remove the yoke pin, disconnect the yoke from the slack
adjuster, remove the mounting nuts, washer, and lock
washers and remove the combination spring brake. While
removing, use care to prevent the combination spring
brake from falling.
INSTALLATION:
1. Install the combination spring brake using the furnished
hardware. Torque the mounting nuts to 110 ft/lbs.
Connect the yoke to the slack adjuster and install the
yoke pin and the cotter pin.
2. Reconnect the emergency air line to the emergency
porthole and reconnect the service air line to the service
porthole.
3. Pressurize the service chamber by putting air into the
service port. Do not exceed 120 psig. Test for leaks
around the clamps. No leaks are acceptable.