Pontiac FIREBIRD 1972 Service Manual page 491

1972 PONTIAC SERVICE MANUAL
cavity ofpo wer piston. I f reaction piston is too
short, both levels of gage will clear 'hose" of
reaction piston. I f either condition exists, a
separate kit of three selective reaction pistons
(differeing in length and color) must be ob-
tained to permit use ofpiston that meets correct
size requirements of step (e).
Care must be taken to insure that gage is not
"cocked".
After determination of correct reaction piston, apply
a light film of silicone lubricant to O.D. of rubber
reaction disc, place disc in large cavity of secondary
power piston and push disc down to seat on reaction
piston.
Unlock secondary power piston from primary power
piston.
Assemble primary diaphragm to primary support
plate from side of support plate opposite locking
tangs. Press raised flange on I.D. of diaphragm
through center hole of support plate. Be sure that
edge of support plate center hole fits into groove in
raised flange of diaphragm. Lubricate diaphragm
I.D. and raised surface of flange (that fits into groove
in primary power piston) with light coat of silicone
lubricant.
Mount Tool J 23101 (small diameter end up) in a
vise. Position primary power piston so that the two
radial slots in piston fit over ears of tool.
Fold primary diaphragm away from O.D. of primary
support plate.
Holding edges of support plate, with locking tangs
down, place primary support plate and diaphragm
assembly over tube of primary power piston. Flange
on I.D. of primary diaphragm will fit into groove in
primary power piston.
Grip edges of primary support plate, press down, and
rotate clockwise until tabs on primary power piston
contact the stops on support plate.
Place power head silencer on tube of primary power
piston so that holes at base of tube are covered.
Apply silicone lubricant to O.D. of primary power
piston tube.
Remove primary piston assembly from Tool J 23 101
and lay it aside.
Assemble secondary diaphragm to secondary sup-
port plate form side of support plate opposite locking
tangs. Press raised flange on I.D. of diaphragm
through center hole of support plate. Be sure that
cone lubricant to I.D. of secondary diaphragm and
raised surface of flange (that fits into groove in sec-
ondary power piston).
22. Mount Tool J 23101 (with large diameter end up) in
vise. Position secondary power piston so that radial
slots in piston fit over ears of tool. Apply light coat
of silicone lubricant to tube of secondary power pis-
ton.
23. Fold secondary diaphragm away from O.D. of sec-
ondary support plate.
24. Holding edges of support plate, with locking tangs
down, place secondary diaphragm and support plate
assembly over tube of secondary power piston.
Flange on I.D. of secondary diaphragm will fit into
groove in secondary piston.
25. Grip edges of secondary support plate, press down,
and rotate counterclockwise until tabs on secondary
power piston contact stops on support plate. Fold
secondary diaphragm back into position on secorrd-
ary support plate. Leave the secondary power piston
assembly on Tool J 23101 in vise.
26. Apply light coat of talcum powder or silicone lubri-
cant to bead on O.D. of secondary diaphragm. This
will facilitate reassembly of front and rear housings.
27. Place secondary diaphragm support ring on second-
ary power piston assembly so that it rests on edge of
diaphragm.
28. Hold housing divider so that formed over flange (that
holds the primary diaphragm) of divider faces down.
Place secondary bearing in I.D. of divider so that
extended lip of bearing faces up.
29. Lubricate I.D. of secondary bearing with silicone lu-
bricant.
30. Position secondary bearing protector Tool J 23 188 on
threaded end of secondary power piston.
3 1. Hold housing divider with formed flange (that holds
the primary diaphragm) facing up. Press divider
down over tool and onto secondary power piston tube
where it will rest against diaphragm support ring
(Fig. 5D- 18). Remove Tool J 23 188 from secondary
power piston, however, do not remove secondary
power piston subassembly from Tool J 23101.
32. Pick up primary power piston assembly and position
small end of air valve return spring on air valve so
that it contacts air valve retaining ring.
33. Fold primary diaphragm away from O.D. of primary
support plate.
edge of support plate cent& holi fits into groove in
34. Position primary power piston on tubular portion of
raised flange of diaphragm. Apply thin coat of sili-
secondary power piston, making sure that air valve