Chevrolet 1977 Monte Carlo, Repair Manual

Page: 151 / 428

BRAKES 5-15
SUPPO RT PLATE
R EM O V E R A N D
INSTALLER J-21524
O W E R
P IS T O N
-SUPPORT
PLATE
POWER
PISTON
3 /8 "
EXTENSION
J-9746
F ig . 5 - 8 C - - R e m o v in g S u p p o r t P la te
4. Position new "O" ring on air valve in second groove
from push rod end.
5. On reassembly o f power piston, floating control
valve assembly must be replaced w ith a new one since the
force required to rem ove it distorts com ponent parts.
Fig. 5-9C~Rem oving Power Piston Snap Ring
F ig . 5 - 1 0 C - - R e m o v i n g A i r V a lv e A s s e m b ly
6. Place floating control valve on push rod-air valve
assem bly so flat face o f valve will seat against valve seat on
air valve.
7. W ipe a thin film o f Pow er Brake Lube (or equivalent)
on large O .D . o f floating control valve and on "O" ring on
air valve.
8. Press air valve-push rod assem bly, air valve first,
on to its seat in tube o f power piston.
9. Place floating control valve retainer over push rod
so flat side seats on floating control valve.
10. Start floating control valve and its retainer into
pow er piston tube. Press the floating control valve to seat
in the tube, by placing J -2 1601-01 Floating C ontrol Valve
R etainer Installer on top o f retainer and pushing dow n by
hand (fig. 5-11C).
11. After floating control valve is seated, position push
rod lim iter washer over push rod and down onto floating
control valve. A ir filter elem ent can now be stretched over
end o f push rod and pressed into pow er piston tube.
12. A ssem ble pow er piston diaphragm to diaphragm
support plate from side o f support plate opposite locking
tangs. T he raised flange o f diaphragm is pressed through
hole in center o f support plate. Be sure that edge o f center
hole fits into groove in flange o f diaphragm .
13. Pull diaphragm away from O .D . o f support plate
so that support plate can be gripped w ith hands.
14. W ith pow er piston still positioned on holding tool
in vise, coat bead o f diaphragm that contacts power piston
w ith Pow er Brake Lube (or equivalent).
15. H old in g support plate by m etal, with locking tangs
down, place support plate and diaphragm assembly over
tube o f power piston. T he flange o f diaphragm will fit into
groove on power piston (fig. 5-12C).
16. Press down and rotate support plate clockw ise,
until lugs on power piston com e against stops on support
plate (fig. 5-12C).
PUSH ROD - AIR VALVE ASSEM BLY
SN A P RIN G
POW ER PISTON
O V E R H A U L M A N U A L