Pontiac tempest 1968 Service Manual page 193

5A-10
1968 P O N T I A C SERVICE M A N U A L
26. Assemble power piston to rear housing by
pushing tube of power piston through rear housing
from side opposite studs.
27. Wipe tube of reaction retainer with power
brake lube and lay assembly aside.
28. Place front housing In vise with master cyl­
inder down. Lubricate I.D. of support plate seal with
power brake lube. Position power piston return
spring over inset in front housing.
29. Lubricate beaded edge of diaphragm lightly
with talcum powder. Hold rear housing and power
piston assembly over front housing with master
cylinder push rod down and position rear housing
so that scribe marks on housings w i l l be in line when
i t is rotated into locked position.
30. Pontiac - Place tool J 9504 In position on
rear housing.
Tempest and F i r e b i r d - Place a rod on rear
housing (reverse step 5, Brake Unit--Disassemble)
or use tools J 22893-01 and J 9504. Press down to
check that bead of diaphragm is positioned between
edges of housings. I f this Is satisfactory, apply ad­
ditional pressure on rear housing and, at the same
time rotate housing clockwise into locked position.
If housings are not easily locked, hold housing t o ­
gether and apply vacuum to check valve in front
housing. This w i l l draw housings together and w i l l
ease locking procedure.
CAUTION: Do not pat pressure on power piston
tube when locking housings and take care not to
break or bend studs in rear housing.
31. Pontiac - Place felt silencer i n end of boot.
Stretch boot over valve operating rod and rear hous­
ing flange; clevis can now be re-assembled on the
valve operating rod.
Tempest and F i r e b i r d - Push felt silencer
over valve operating rod to seat against end of power
piston tube and place snap ring retainer in groove on
rod to hold silencer against power piston tube.
32. Tempest and F i r e b i r d - Seat plastic boot
against rear housing. Raised humps on side of boot
w i l l locate in large holes In center of brackets.
Install jam nut and clevis on the valve operating rod.
GAUGING PROCEDURE (Pig. 5A-15)
1. Place power brake assembly in vise so that
master cylinder is up. Remove master cylinder from
front housing. Master cylinder push rod is now
exposed.
NOTE: GAUGING IS TO BE PERFORMED WITH­
OUT VACUUM.
2. Place the gauge J 22647 over the piston rod i n
a position which w i l l allow the gauge to be slipped
F i g . 5 A - 1 5 Push Rod Adjustment
to the left or right without contacting the studs.
(Fig. 5A-15)
The center section of the gauge has two levels.
The piston rod end should always touch the longer
section of the gauge which extends into the front
housing. The piston rod end should never touch the
shorter section of the gauge.
NOTE: Any variation beyond these limits must
be compensated for by obtaining service adjustable
piston rod and adjusting screw in end to match
height of gauge. Variation beyond these limits can
cause the primary cup to overlap the compensating
port of the master cylinder which will trap fluid
in the hydraulic system causing brake drag,
3. Replace master cylinder on front housing studs.
Install attaching nuts on studs. Torque to 25 lb. ft.
POWER BRAKE ASSEMBLY—INSTALL
1. Place power brake Into position and install four
rear housing to dash attaching lock washers and nuts
from inside of car. Tighten nuts 24 lb. ft. torque.
2. Attach clevis to brake pedal. Install pin and
retainer.
3. Check stop light switch adjustment.
4. Attach vacuum hose to vacuum check valve.
5. Attach hydraulic lines.
6. Bleed brakes as necessary and f i l l fluid reser­
v o i r to level shown in Section 5.
TORQUE SPECIFICATIONS
L B . F T .
Power Cylinder Housing - to - Master
Cylinder Nuts 25
Rear Housing to Pedal Bracket Nuts . . . 24
Push Rod Clevis
(Tempest and Firebird) 12 1/2