Over-All Brake Unit; Separating Front And Rear Shells - Pontiac Grand Prix Service Manual

5D-2 1969 PONTIAC SERVICE MANUAL
Fig. 5D-2 Separating Front and Rear Shells
MINOR REPAIRS
BLEEDING BRAKES
Brakes should be bled in the same manner as standard
brakes, unless a disc brake balance valve is incorpo-
rated in the system (see Section 5E).
STOP LAMP SWITCH
See Section 5 for senice.
MAJOR REPAIRS
MASTER CYLINDER ONLY
-
REMOVE
Certain repair operations, such as replacement of
master cylinder internal parts, permit the master
cylinder to be removed by itself, leaving the power
cylinder, pedal, and brackets in the car.
1. Remove hydraulic connections from master cylinder,
pump
fluid from cylinder into a container and dispose
of fluid. Cover openings at cylinder and pipes to
exclude dust, dirt, etc.
2. Remove master cylinder attaching nuts and remove
master cylinder from power section.
POWER CYLINDER ONLY REMOVE
1. Remove vacuum check valve.
2. Remove master cylinder and position it away frdm
power cylinder.
NOTE: Do not disconnect hydraulic fluid lines; be
carefitl not to bend or kink lines.
3. Remove clevis pin retainer at brake pedal.
4. Remove four power unit to dash attaching nuts.
5. Remove power cylinder.
OVER-ALL BRAKE UNIT
-
DISASSEMBLE
POWER CYLINDER
-
DISASSEMBLE
(Fig.
5D-1)
4
1.
Clean exterior of power cylinder.
2. Scribe a line across front and rear housings to
-
facilitate reassembly.
3. Remove front housing seal.
4. Attach tool J 2280541 to master cylinder studs of
power cylinder with two nuts.
5. Place assembly in vise. Attach tool J 9504 over rear
housing studs. (Fig. 5D-2)
6. Applying downward pressure, rotate rear housing
counterclockwise to unlock housings. It is normal for
this operation to require heavy pressure to unlock
housings.
NOTE: Rotate slowly as housing
is
under spring tension.
7. Remove rear housing and power piston assembly by
lifting straight up slowly and lay it aside on a clean
smooth surface.
8. Remove power piston return spring and retainer
plate.
9.
Dispose of vacuum check valve grommet in front
housing.
10. Remove boot retainer and boot from rear housing.
The boot and felt silencer must be pulled over the
pushrod ffeyeff to remove.
11.
Remove power piston group from rear housing and