Pontiac tempest 1968 Service Manual page 187

5A-4
1968 P O N T I A C SERVICE M A N U A L
RETURN
S P R I N G
w
VACUUM
CYLINDER
PUSH ROD
I B *
1
HP
•
F i g . 5 A - 4 Brake Unit Mounted In Vise
2. Remove reaction retainer, vacuum cylinder
push rod, reaction plate, three reaction levers and
a i r valve spring. (Fig. 5A-10)
3. Remove small reaction bumper and air valve
spring retainer from air valve.
4. Place square end of tool J 21524 In vise holding
support plate and power piston with tube end of
piston facing up.
5. Pull diaphragm edges away from support plate
and position on tool J 21524 so that three lugs on
tool fit Into three notches i n power piston. (Fig.
5A-11)
6. Press down on support plate and rotate counter­
clockwise until support plate separates from power
piston (Fig. 5A-12).
1. Remove diaphragm from support plate.
8. Remove silencer from neck of power piston
tube.
9. Position power piston i n vise padded with shop
towels with tube end down.
CAUTION; Do not clamp on tube as outside sur­
face of tube acts as bearing surface.
i
F i g . 5A-5 Removing Rear Housing
10. Remove snap ring on air valve using Truarc
Pliers and place power piston with tube end down in
arbor press.
11. Press air valve from power piston using rod
not exceeding 1/2" diameter. Removal of valve re­
leases floating control valve, floating valve retainer,
push rod limiter washer and air filters (Fig. 5A-13).
NOTE: The floating control valve cannot be re­
moved from push rod. It will be necessary to
service complete push rod air valve assembly.
12. Remove O-ring seal from the air valve in
second groove from air valve operating rod end.
13. Remove vacuum cylinder push rod from center
of reaction retainer and O-ring seal from groove
on the rod.
MASTER CYLINDER-DISASSEMBLE (Fig. 5A-14)
Refer to Section 5 - Standard Brakes for disas­
sembly procedures.
INSPECTION AND CLEANING
Thoroughly wash all parts in alcohol and air dry.
Blow dust and cleaning fluid out of all internal pass-