Removal Of Rear Shell Vacuum Seal; Diaphragms, Plates, Retainer And Plunger; Valve Rod, Retainers, Filters And Poppet; Power Unit Special Tool Combination - Pontiac Grand Prix Service Manual

HEAVY DUTY POWER BRAKES
5C -3
LVE RETURN SPRING
. .
Fig. 5C-2 Valve Rod, Retainers, Filters and Poppet
5. Rotate spanner wrenches (J 9504) counterclockwise
to release position (to point where cutouts in front shell
are in line with lances in rear shell).
6.
Slowly release pressure on assembly.
CAUTION: Diaphragm return spring is under pressure.
Use care in separating shelh to avoid the spring flying
out.
7. Using fingers, remove diaphragm assembly from
rear shell (Fig. 5C-4).
REMOVAL OF REAR SHELL VACUUM SEAL (Fig. 5C-1)
NOTE: Do NOT remove rear seal unless seal is
defective.
Place rear shell on bench with studs up and drive out
seal with punch or screwdriver.
DIAPHRAGMS, PLATES, RETAINER AND PLUNGER
-
DISASSEMBLE (Fig. 5C-5)
1.
Wet rear diaphragm spring retainer with alcohol
and remove, using fingers only. Remove rear dia-
phragm from rear plate.
assembly on hex stock with hex opening in center of
front plate on bar. Twist rear plate counterclockwise,
using hand leverage only either on atmospheric pressure
channel or on outside circumference of rear plate.
After plates have been loosened, remove assembly
from vise and complete disassembly on bench, front
plate down.
3. Unscrew rear plate completely and carefully lift it
off front plate hub, grasping valve plunger and spring
with other hand and remove them from bore of front
plate hub.
2. Set 1-1/16" hex bar stock about 2" long or tool J
22839 in bench vise. Set Diaphragm and Plate
Fig. 5C-3 Power Unit Special Tool Combination