BRAKES - AIR
TRUCK SERVICE MANUAL
SERVICING POWER UNITS
AIR CHAMBER DIAPHRAGM
The following procedures can be used to replace the
diaphragm plate and wedge guide of the brake air
diaphragm boot and retainer clamp assembly,
REMOVE POWER UNIT FROM BRAKE ASSEMBLY
Remove brake lines
Using a drift or other blunt tool and hammer,
loosen the collet nut.
With welded on spider mounted brakes
employing open ends, the entire actuation system can be
taken off at this time, if desired, as one assembly by
Unthread the power unit out of plunger housing.
removing four spider to plunger housing capscrews.
However, the hub, drum and dust shield will have to be
NOTE: The wedge assembly can be removed and
taken off before removing the actuation system.
serviced at this time if desired.
DISASSEMBLE AIR CHAMBER
Remove diaphragm, diaphragm plate and
With power unit removed from brake assembly,
remove clamp ring nuts, bolt, wedge guide from non-
Spread clamp ring and remove pressure half