Pontiac firebird 1968 - Page 205

5C-2
1968 PONTIAC SERVICE MANUAL
1. Clevis
2. Dust Guard
3. Valve Rod
4. Silencer
5. Retainer
6. Air Filters
7. Valve Return Spring
8. Poppet Retainer
9. Poppet
10. Rear Shell
11. Rear Seal
12. Rear Diaphragm Spring
Retainer
13. Rear Diaphragm
14. Rear Plate
15. Valve Plunger
16. Valve Plunger Spring
17. Square Ring Seal
18. Center Plate
19. Front Diaphragm
20. Front Plate
21. Reaction Disc
22. Hydraulic Push Rod
23. Power Diaphragm Return
Spring
24. Front Shell
25. Front Vacuum Seal
26. Rubber Grommet
27. Vacuum Check Valve
Fig. 5C-1 Power Unit—Exploded View
hex and threaded end of valve rod and small diameter
of dust guard with alcohol and then carefully remove
dust guard and silencer from valve rod and scalloped
hub of rear shell. Remove hydraulic push rod by
pulling it straight out of front shell. Slide front seal
off adjustment nut end of push rod.
VALVE ROD, RETAINERS, FILTERS AND POPPET
PARTS-REMOVE (Fig. 5C-2)
Remove air filters from valve hub with ice pick.
USE CARE TO AVOID DAMAGING PLASTIC HOUS-
ING. With valve rod in vertical position, squirt
alcohol down rod to wet rubber grommet in valve
plunger on ball end of valve rod. Install 3/8-24" nut
on threaded end of valve rod and clamp nut securely
in vise (see Fig. 5C-2 inset). Leave just enough
space between steel retainer on plastic valve hub and
side of vise jaw to insert two medium-sized open
end wrenches. Use wrench nearest vise as a pry to
force the valve plunger grommet (and power section)
off the ball end of the valve rod.
CA UTION: When separating valve rod from
plunger, hold power unit to prevent it from falling
to floor. Use care when prying with wrenches to
avoid damaging plastic valve housing.
Remove valve rod from vise. Carefully pry re-
tainer off end of valve housing and remove valve
return spring, poppet retainer and poppet.
POWER SECTION DISASSEMBLY (Fig. 5C-4)
1. Assemble special tool combination as shown in
Fig. 5C-3.