Bendix Commercial Vehicle Systems PIGGYBACK SPRING BRAKE - Manual (Page 4)

4
FIGURE 4 - CAGING THE PIGGYBACK
ADAPTER
RETURN SPRING SERVICE
RETURN SPRING
YOKE
LOCKNUT
EMERGENCY
DIAPHRAGM
SERVICE
DIAPHRAGM
RELEASE TOOL
PRESSURE PLATE
MAIN SPRING
• DO NOT service a piggyback spring brake
chamber if it has structural damage of any kind.
Replace the complete assembly. Dismount a
damaged piggyback spring brake by first cutting
the service push rod with an acetylene torch to
relieve any force it might have.
• Do not strike any part of a spring brake chamber
for any reason. This may cause structural
damage.
• Be careful not to drop a spring brake chamber
at anytime.
• A piggyback spring brake chamber cannot have
the emergency diaphragm replaced. Replace the
whole piggyback spring brake chamber.
• Always work from the side of the piggyback
spring brake chamber(s). Never work from the
front or back.
MECHANICAL RELEASE (CAGING) OF THE
BENDIX PIGGYBACK SPRING BRAKE
NOTE: The Bendix Piggyback Spring Brake Chamber is
not shipped caged. It must be caged prior to any work
being done.
1. Remove the dust cap from the keyhole in the center
of the piggyback spring brake chamber.
2. Remove the release tool assembly from the side
pocket of the adaptor base.
3. Insert the release tool (T-bolt) through the release tool
keyhole and into the pressure plate.
4. Turn the release tool 1/4 turn clockwise.
5. Pull on the release tool to seat it in the pressure
plate properly.
6. Put on the release washer and nut.
7. To cage the main spring, tighten the release nut with a
hand wrench and ensure the service pushrod
is retracting.
8. Do not over torque the release tool assembly. Maximum
torque is 35 ft/lbs.
WARNING!
Do not use an impact wrench. An impact wrench may
over torque the release tool and cause damage to the
pressure plate.
9. The threaded portion of the release tool will extend
approximately 2.9 inches out of the nut when fully
released.
MECHANICAL RELEASE (CAGING) AND
REMOVAL OF THE PIGGYBACK SPRING BRAKE
CHAMBER TO BE REPLACED
NOTE: The piggyback spring brake chamber can be
replaced with the service brake chamber mounted to the
vehicle or removed for ease of access. To remove the
assembly from the vehicle, perform the steps outlined in
“Removal and Installation of the Combination Spring Brake.”
WARNING!
• Do not mechanically release (cage) the spring if
there is any structural damage to the brake. Caging
the spring in such a chamber may cause serious
injury or death. Replace the complete assembly.