Pontiac Fiero 1988 Service Manual page 265

5D24 POWER HEAD ASSEMBLY
STAKE
STAKE AT TWO TABS
180° APART
STAKE
UNSTAKED TAB
bTAKING TAB SOCKET WITH SCREWDRIVER
HM0006-5P2-AB
Figure 6 Staking Procedure
(Figures 7 thru 11)
Disassemble
1. Remove booster (35) and disconnect housings (9
and 10) as previously described.
2. Piston rod (12), reaction retainer (13) and power
head silencer (14).
3. Power piston assembly (41) along with pushrod
(32).
m Grasp assemby at outside edge of housing
divider (19) and diaphragms (16 and 20).
• Hold with pushrod (32) down against a
hard surface.
• Use a slight force or impact to dislodge
diaphragm retainer (15).
4. Primary diaphragm (16) and primary support
plate (17) from housing divider (19).
5. Primary diaphragm (16) from primary support
plate (17).
6. Secondary diaphragm (20) and secondary
support plate (21) from housing divider (19).
7. Secondary piston bearing (18) from housing
divider (19).
8. Secondary diaphragm (20) from secondary
support plate (21).
Inspect
Parts for:
• Corrosion
• Nicks
• Cracks
•
L
2.
3.
6.
7.
8.
10.
11.
12.
m Cuts
• Scoring
m Distortion
• Excessive wear
Use crocus cloth to polish away minor corrosion
to diaphragm supports, or housing divider.
Clean
All parts in clean denatured alcohol.
Do not immerse power piston and pushrod
assembly in alcohol, rather wipe clean with an
alcohol dampened cloth.
Dry with unlubricated compressed air.
Assemble
Lubricate inside diameter of secondary
diaphragm (20) lip, inside diameter of primary
diaphragm (16) lip and secondary piston bearing
(18) with a thin layer of silicone grease.
Secondary diaphragm (20) into secondary
support plate (21).
Secondary diaphragm (20) and support plate (21)
over power piston assembly (41) and pushrod
(32). Use J 28458 as a guide to protect the power
piston.
Secondary piston bearing (18) into housing
divider (19) with flat surface of bearing on same
side as six raised lugs on divider.
Secondary piston bearing (18) and housing
divider (19) over power piston assembly (41) and
pushrod (32). Use J 28458 as a guide.
Primary diaphragm (16) into primary support
plate (17).
Fold primary diaphragm (16) up, away from
primary support plate (17).
Primary diaphragm (16) and support plate (17)
over power piston assembly (41) and pushrod
(32).
Fold primary diaphragm (16) back into position
and pull diaphragm OD over formed flange of
housing divider (19).
• Check that beads on secondary diaphragm
(20) are seated evenly around complete
circumference.
New diaphragm retainer (15) and seat using J
28458 Retainer Installer.
Silencer (14), reaction retainer (13) and piston
rod (12).
Reassemble booster as previously described.
POWER PISTON OVERHAUL
Tools Required:
J 29282 Air Valve Push Rod Retainer
Installer
(Figures 12 thru 14)
Disassemble
1. Reaction body retainer (24).
Reaction body (25).