Pontiac tempest 1968 Service Manual page 198

B E N D I X P O W E R B R A K E 5B-3
1. Clevis
2. Dust Guard (Boot)
3. Air Silencers and
Filter
4 . Rear Housing
5. Rear Vacuum Seal
6. Diaphragm
7. Control V a l v e
(Valve Rod and
Plunger)
8. V a l v e Plunger Stop Key
9. Diaphragm Plate
(Power Piston)
10. Reaction Disc
11. Hydraulic Push Rod
12. Diaphragm Return Spring
13. Front Housing
14. Grommet
15. Vacuum Check V a l v e
16. Front Vacuum Seal
Fig. 5B-2 Power Brake—Exploded View
rear piston and use Tru-Arc pliers to remove snap
ring from groove in master cylinder bore.
3. Remove rear piston and spring assembly and
discard. Do not attempt to disassemble it since
complete new assembly is provided in repair kit.
4. Remove front piston assembly, front return
spring and retainer. Slide primary cup and protector
off nose of front piston. Use dull scribe to lift both
secondary seals from the grooves at rear end of
front piston. Discard all old rubber parts.
NOTE: Check valves should not be replaced un­
less one or more of conditions exist as outlined in
Section 5 under Master Cylinder Disassemble.
5. Install spare tube nut in outlet ports. Place
thin washer on self-tapping screw and install screw
in tube seat with washer bottomed against tube nut.
(Fig. 5B-5) Hold screw with screwdriver and use
wrench to remove tube nut, screw, washer and tube
seat. Remove rubber check valve and spring from
both output ports and discard.
INSPECTION—CLEANING
Thoroughly wash all parts in alcohol and air dry.
Blow dust and cleaning fluid out of all internal pas­
sages. If inside of front housing is slightly scored
or scratched, clean with crocus cloth or fine emery
cloth. If scratches cannot be removed, replace
housing.
All rubber parts should be replaced, regardless
of condition, and those parts which come in contact
with brake fluid should be rewashed in clean alcohol
before reassembly.
CAUTION: It is important that all parts be placed
on a clean paper or cloth after being cleaned to
prevent the possibility of dirt being assembled into
unit or grease contacting any rubber parts.
INSPECT POWER BRAKE ASSEMBLY
Inspect all parts for scoring, pitting, dents or
nicks. Small imperfections can be smoothed out
with fine emery cloth or parts replaced if badly
nicked, scored, or otherwise damaged.
INSPECT HYDRAULIC MASTER CYLINDER ASSEMBLY
Inspect bore from the open end. The bore should