BRAKE CHAMBERS
SUB-SECTION 9D
LEAKAGE TEST. Perform the following test periodically
to determine whether or not the brake chambers is suitable
for continued service:
1. Have an assistant make and hold a full brake application.
2. Coat the non-pressure housing, clamping ring, and inlet
ports and fittings with a soap solution. No leakage is per-
missible at these points.
3. If leakage is detected around the Clamping ring, the
clamp bolt should be tightened, but only enough to stop
the leakage. Excessive tightening could distort the dia-
phragm sealing flange.
4. If leakage occurs at the non-pressure housing or leakage
cannot be stopped by tightening the clamp bolt, the brake
chamber should be disassembled as follows:
DISASSEMBLY. The following procedure describes the
Figure 9D-2. Brake Chamber (1038Z170)
method of removing the diaphragm and boot, which are the
items which would cause leakage, when the brake chamber
REASSEMBLY. Install a new diaphragm and boot as fol-
is on the machine (see Figure 9D-2):
lows:
1. Disconnect the air line or lines at the brake chamber.
1. Install a new boot on the diaphragm plate push rod and
press the wedge guide all the way to the end of the push
2. Remove the clamp ring nut and bolt. Spread the clamp
rod.
ring and remove it, while holding the pressure housing in
place.
2. Clean the non-pressure housing with cement thinner or
similar solvent in the area where the boot is to be ce-
3. Hold the diaphragm against the non-pressure housing
mented.
and remove the pressure housing.
3. Apply cement to the non-pressure housing around the
4. Carefully remove the diaphragm while holding the dia-
tube end. Position the diaphragm plate push rod in the
phragm plate against the wedge rod. This will prevent the
tube. Carefully engage the wedge rod so as not to pull it out
wedge assembly from coming out of engagement with the
of the plungers.
plungers.
4. While holding the diaphragm against the wedge assembly,
NOTE
press the boot into portion for cementing.
If the wedge assembly backs out of the plungers at
5. Install a new diaphragm Over the diaphragm plate and
onto the non-pressure housing, while pushing the dia-
anytime during the procedure, it will be necessary to
phragm plate against the wedge assembly.
remove the brake shoes to replace the wedge as-
sembly .
6. Install the pressure housing over the diaphragm. Install
the clamp ring over the non-pressure and pressure housing
5. Continue to hold the diaphragm plate and inspect the
flanges, and secure the clamp ring with the clamp ring bolt
boot. If the boot is torn or not attached to the non-pressure
and nut.
housing, strip the old boot from the housing.
7. Reconnect the air line or lines to the brake chamber.
Have an assistant make and hold a full brake application,
6. Carefully extract the diaphragm plate from the wedge
and check, the brake chamber for leakage. Then road test
assembly. The boot and wedge guide will remain on the
the machine and check brake performance.
diaphragm plate push rod.
9D-2
