Pontiac FIREBIRD 1972 Service Manual page 492

TANDEM DIAPHRAGM POWER BRAKE-MORAINE 5D-15
rotating in a clockwise direction.
Fig. 5 D - 1 8 Installing Housing Divider
36. Continue to tighten primary power piston until it is
securely attached to secondary power piston..
37. Fold primary diaphragm back into position on pri-
mary support plate and pull diaphragm O.D. over
formed flange of housing divider. Check that bead on
diaphragm is seated evenly around the complete ciri
cumference. Remove assembly from tool.
38. Wipe thin film of silicone lubricant on O.D. of piston
rod retainer. Insert master cylinder piston rod re-
tainer into cavity in secondary power piston so that
flat end bottoms against rubber reaction disc in bot-
tom of cavity.
39. Place primary power piston bearing in rear housing
center hole so that formed flange of housing center
hole fits into groove of primary power piston bearing.
Thin lip of bearing will protrude to outside of hous-
ing.
return spring seats down over raised center section of
40. Coat I.D. of primary power piston bearing with sili-
secondary piston. cone lubricant.
35. Grip edge of primary support plate with hands, press
41. If check valve grommet was removed during servic-
down, and start threads on secondary power piston
ing, replace with new grommet in front housing.
into threaded portion of primary power piston by
POWER CYLINDER
ASSEMBLE
PISTON ROD
Fig. 5D-19 Securing Front Housing to Arbor Press
NOTE: Special Tool BT 7004 or J234.56 (Fig.
50-7) may be used for housing assembly as an
alternate to the following method.
1. Secure power section front housing to tools J 8433
and J 6407-02 as shown in Fig. 5D-19.
2. Secure front housing to arbor press (Fig. 5D-19).
3. Position power piston return spring over inset in
front housing.
4. Place piston rod retainer plate on end of power piston
return spring in front housing.
5. Assemble power piston group to rear housing by
pressing tube of primary power piston through rear
housing bearing. Press down until housing divider
seats in rear housing and primary power piston bot-
toms against housing.
6. Assemble rear housing to spanner wrenches J 9504 as
shown in Fig. 5D-20.
7. Hold rear housing assembly (with mounting studs
up) over front housing, so that scribe marks will
be
aligned when housings are locked together.