Table of Contents
Advertisement
5-48
1977 PONTIAC SERVICE MANUAL
NORMAL
LANCE
I
Fig. 5-76 Lances in Front Shell
.
I ,
Fig. 5-77 Unlocking Front and Rear Housings
after using any abrasive.
Inspect all parts and replace any that are damaged or
show excessive wear.
REASSEMBLY OF BENDIX TANDEM
POWER BRAKE UNlT
1. If the rear bearing and seal were removed, press new
bearing and seal into this cavity in the rear shell using Too
J 22677. See Fig. 5-81. The flat rubber surface of the seal
should be 5/16" below the flat, inside surface of the rear shell.
2. Install reaction disc in hub of front plate with small
tip toward hole. Use rounded rod to seat disc.
3. Mount Tool J 22839 in vise.
4. Install front diaphragm on front plate. Long fold of
diaphragm must be facing down.
5. Install Tool J 22733 over threads on front plate hub.
See Figure 5-82.
6. Apply a light film of special seal lubricant to front
plate hub and to seal in center plate, then guide center plate,
seal first on to the front plate hub, being careful not to damage
center plate seal.
7. Apply special seal lubricant lightly to front and rear
bearing surfaces of air valve plunger, being careful not to
apply lubricant to rubber grommet inside plunger. Install
vacuum seal "OW-ring on shoulder of front plate hub and
valve plunger return spring and plunger in base of front plate
hub. See Fig. 5-83.
8. Set rear plate over hub of front plate and, using hands
only, screw plate on hub, making sure that valve and spring
are properly aligned. Hand torque plates to 150 in. lb. Check
travel of valve plunger with index finger.
9. Assemble rear diaphragm to rear plate and place lip
of diaphragm in groove in rear plate. Install diaphragm
retainer over rear diaphragm and lip of center plate. Using
fingers, press retainer until it seats on shoulder of center plate.
See Fig. 5-84.
10. Apply talcum powder to inside wall of rear housing
and special seal lubricant to the scalloped cutouts of front
housing and to seal in rear housing; assemble diaphragm and
plate assembly in rear housing by carefully guiding rear plate
hub through seal in rear housing. Bosses on center plate must
be aligned between lances in rear housing for reassembly.
Work outer rim of front diaphragm into rear housing with
screwdriver blade so that it is under lances in housing.
11. Install rear housing in Tool J 23456.
12. Install diaphragm return spring in rear housing.
13. Place front housing over rear housing and align
scribe marks.
14. Tighten until diaphragm edge is fully compressed
and tangs on front housing against slots on rear housing.
15. Rotate bar clockwise until housings are locked
together. Remove from tool.
16. Bend the tabs of the four deep lances back to their
original position.
17. Wet poppet valve with alcohol and assemble in rear
plate hub, small end first; wet poppet retainer with alcohol
and assemble with shoulder inside poppet. Assemble retainer,
filters, silencer over ridge on rod and return spring over ball
end of operating valve rod. Wet grommet in valve plunger
with alcohol and guide air valve rod into valve plunger. Tap
end of operating valve rod with plastic hammer to lock ball
in grommet. Press filters and silencers into hub and install
retainer on hub.
18. Assemble silencer in dust boot, wet dust boot opening
with alcohol and assemble over operating valve rod and over
flange of rear housing.
19. Install check valve and grommet, if removed.
20. Apply special seal lubricant to piston end of
hydraulic push rod and insert in cavity in front plate. Twist
rod to eliminate air bubbles at reaction disc. Assemble seal
over push rod and press into recess in front housing.
GAGING OF BENDIX TANDEM POWER
BRAKE UNlT
1. Place the power head assembly in a padded vise (front
housing up). Do not clamp tight.
2. Insert the master cylinder piston rod, flat end first,
into the piston rod retainer.
3. Press down on the master cylinder piston rod (with
approximately a 40-50 pound load) to be sure it is properly
seated.
4. Remove the front housing seal to assure that no
vacuum is in the power head while gaging.
5. Place Gauge J 22647 over the piston rod in a position
which will allow the gauge to be slipped to the left or right
Advertisement
Table of Contents
