BENDIX SD-02-4500 User Manual

FIGURE 6 - SERVICE DIAPHRAGM

SERVICE

CLAMP RING

RELEASE
TOOL

NON-PRESSURE

HOUSING

SERVICE

DIAPHRAGM

PIGGYBACK

CHAMBER

4. Uncage the main spring and return the release tool into

the release tool side pocket.

5. 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).

REPLACING THE SERVICE DIAPHRAGM

To replace the service diaphragm, it is not necessary to
remove the complete combination spring brake from the
vehicle. However, it can be removed for ease of access. To
remove the combination spring brake, perform the steps
outlined in "Removal and Installation of the Combination
Spring Brake".

WARNING!

•

A piggyback spring brake chamber cannot have
the emergency diaphragm replaced. Replace the
whole piggyback spring brake chamber.

1. Protect the service push rod with tape, and lock the vise

grips on the push rod close to the non-pressure plate.
(This will hold the rod in the applied position).

2. Ensure that the piggyback spring brake chamber is

caged. To cage the piggyback spring brake chamber,
perform the steps outlined in either "Mechanical Release
of the Bendix Piggyback Spring Brake" or "Mechanical
Release of the Piggyback Spring Brake to be Replaced".

3. Mark the service clamp ring and non-pressure plate to

ensure proper alignment of parts during reassembly.

4. Remove the service clamp ring assembly and the

piggyback chamber. The service clamp ring is closest
to the non-pressure plate and slack adjuster. See
provided illustrations if in doubt.

WARNING!

Do not remove the spring chamber clamps.

5. Visually inspect the service diaphragm for excessive wear,

damage or cracks. Replace if needed.

6. Line up the piggyback spring brake chamber, the service

diaphragm, and the non-pressure housing, ensuring that
they are centered.

7. Reassemble the service clamp assembly. Ensure all

parts are seated properly and remain centered.

8. Torque the clamp nuts to 25 ft/lbs. Remove the vise grips

from the service push rod.

9. Reconnect the emergency air line to the emergency

porthole and reconnect the service air line to the
service porthole.

10. 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.

11. Uncage the main spring and return the release tool into

the release tool side pocket.

12. Replace the dust cap in the keyhole.

WARNING!