GMC 1989 Light Duty Truck Repair Manual page 328

5-10 BRAKES
1. B o o t
2. S i l e n c e r
3. V a c u u m c h e c k Valve
4. G r o m m e t
5. F r o n t H o u s i n g S e a l
6
. P o w e r P is t o n B e a r in g
7. R e a r H o u s i n g
8
. F ro n t H o u s i n g
9. R e t u r n S p r i n g
10. P is t o n R o d ( G a g e d )
11. R e a c t i o n R e t a i n e r
12. F il t e r
13. D i a p h r a g m R e t a i n e r
14. D i a g h r a g m
15. D i a p h r a g m S u p p o r t
16. P o w e r P is t o n a n d
P u s h r o d A s s e m b l y
19. P u s h r o d
25. R e a c t i o n B o d y
R e t a i n e r
Install or C onnect (Figure 20)
Tools Required:
J 23456 Power Brake Booster Disassembly
and Reassembly Tool
J 28458 Power Piston Seal Protector
J 22647 Pushrod Height Gage
Diaphragm (14) into the diaphragm support (15).
• Lubricate the inside diam eter of the d ia ­
phragm lip with a thin layer of silicone grease.
Diaphragm and diaphragm support onto the power
piston and pushrod assembly.
New diaphragm retainer (13) (figure 22).
• Seat the retainer using J 28458.
Filter (12), reaction retainer (11) and piston rod (10).
Reaction body retainer (25).
Figure 2 1 — U nlocking and Locking B ooster
Figure 20—Single Diaphragm Vacuum Booster Components
Power piston bearing ( 6
6
.
• Lubricate the inside and outside of the bearing
with silicone grease.
7. Power piston group into the rear housing (7).
8
. Return spring (9).
9. Front housing to the rear housing.
• Align the marks made during disassembly.
• Use J 23456 to apply force in a clockwise di­
rection to lock the front and rear housings.
• Stake the housing at two tabs 180 degrees
apart (figure 23).
— Do not stake a tab that has previously
been staked.
• Assembly can be aided by connecting a vac­
uum source to the booster.
10. Grommet (4) and vacuum check valve (3).
Figure 2 2 — Installing th e D iaphragm R etain er
F-05821
) into the rear housing.