Pontiac tempest 1968 Service Manual page 199

5B-4
1968 P O N T I A C SERVICE MANUAL
C O N T R O L
y V A L V E A S S E M B L Y
f O P E R A T I N G R O D
VALVE P L U N G E R •
STOP KEY
Fig. 5 B - 3 V a l v e Plunger Stop Key—Remove and Install
be free of scoring, rust, pitting or etching. If any
of these are apparent, master cylinder must be re­
placed. If it appears that contaminants have dam­
aged the bore, replace damaged parts and flush out
entire brake system including wheel cylinders.
The sealing surfaces should be clean and smooth.
Check for cracks and damaged threads. Be sure that
the by-pass and compensating ports to the master
cylinder reservoirs are not restricted.
Check for distortion of all springs and deteriora­
tion of all rubber parts. Any evidence of soft or
swollen rubber parts indicates contaminated brake
fluid requiring flushing of the entire brake system
and replacement of wheel cylinder cups as well as
all rubber parts in master cylinder.
Fig. 5 B - 5 Master Cylinder—Exploded View
1. Snap Ring
2. Splash Shield
Retainer
3. Splash Seal
4. Secondary Seal
5. Rear Piston and
Spring Assembly
6. Primary Cup
7. Secondary Seals
8. Front (Floating)
Piston
9. Protector
10. Primary Cup
11. Retainer
12. Front Piston Return
Spring
13. Piston Stop Screw
and Seal
14. Tube Seats
15. Check Valves
16. Springs
17. Master Cylinder
Casting
18. Hermetic
Diaphragm
19. Reservoir Cover
20. Bale-Type
Retainer
INSPECT AIR FILTERS
DIAPHRAGM DIAPHRAGM PLATE
RETURN SPRING ( POWER PISTON )
DIAPHRAGM
Replace felt air filters if dirty. Do not clean.
POWER UNIT AND
MASTER CYLINDER-ASSEMBLE
MASTER CYLINDER-ASSEMBLE (Fig. 5B-5)
1. Clamp master cylinder in vise with front end
slightly below horizontal.
2. Install new secondary seals, back to back, in
grooves on rear end of front piston. Dip seals in
brake fluid and lift them carefully into grooves with
dull scribe. Slide protector and primary cup onto
nose of front piston.
Fig. 5 B - 4 Power Piston—Exploded View
3. Stack front piston return spring and retainer
on nose of front piston and dip assembly in brake