Pontiac tempest 1968 Service Manual page 186

DELCO-MORAINE P O W E R B R A K E
5A-3
H O S I V A C U U M C Y L . T O CARS
6 CYL.
S I N G L E
BBL. CARB. ENG
HOSE V A C U U M CYL. TO C A R B
6 CYL. 4 BBL. C A R B . ENG.
8 CYL. E N G .
A S S E M B L E N U T F I N G E R - ,
T I G H T A G A I N S T S H O U L D E R
ON P U S H R O D . H O L D N U T
A N D T O R Q U E CLEVIS TO
SPECIFIED TORQUE.
T O R E A R B R A K E S
FRAME
©
V I E W A
WITH DISC BRAKES
2. Scribe a line across the front and rear housings
to facilitate reassembly.
3. Remove clevis from the valve operating rod.
4. Remove boot and silencer.
F i g . 5A-3 Firebird Power Brake System
8. Remove power piston return spring.
9. Scribe a line across front housing and master
cylinder assembly and remove nuts and lock washers
from master cylinder studs. Remove master cylinder
assembly from front housing.
5. Using tool J 9504, rotate rear half housing
counterclockwise to unlock rear half from front
housing. Disassembly of Tempest and Firebird units
may be facilitated by using tool J 22893-01.
NOTE: Rotate slowly as housing is under spring
load.
6. Remove rear housing and power piston assem­
bly by lifting straight up slowly and lay it aside on a
clean smooth surface (Fig. 5A-5).
7. Remove power piston assembly from rear
housing.
10. Remove front housing seal, vacuum check valve
and grommet from front housing (Fig. 5A-6 and
5A-7).
POWER PISTON-DISASSEMBLE (Fig. 5A-8)
CAUTION: Care must be taken in handling dia­
phragm of power piston group. Diaphragm should
be guarded against grease, oil and foreign matter
and must be protected from nicks or cuts that
might be caused by rough surfaces, damaged tools
or dropping the piston.
1. Remove lock ring from power piston by prying
from under locking lugs. (Fig. 5A-9)