5-12 BRAKES
B o ot
S ile n c e r
V a cu u m C h e c k Valve
G r o m m e t
F ront H o u s in g Seal
P rim ary P is to n B e a rin g
Rear H o u s in g
Front H o u s in g
Return S p rin g
P iston Rod (Gaged)
R e ac tio n R e ta in e r
Power Head S ile n c e r
D ia p hrag m R e ta in er
Prim ary D ia p h ra g m
Primary S u p p o rt Plate
S e c o n d a ry P is to n Bearing
H o u s in g D ivid e r
S e c o n d a ry D ia p h ra g m
S e c o n d a ry S u p p o rt Plate
R e a c tio n Disc
R e a c tio n P isto n
R e a c tio n B o d y R eta iner
R ea c tio n B o dy
A ir Valve S p rin g
R e a ctio n B u m p e r
R e ta in in g Ring
Filte r
30. R e ta in e r
31. O-Ring
32. A ir Valve Push Rod A s s e m b ly
33. P ower P is to n
J 28458 Power Piston Seal Protector
J 22647 Pushrod Height Gage
1
. Lubricated O-ring (31) onto the air valve pushrod as
sembly (32).
2. Air valve pushrod assembly (32) into the power pis
ton (41).
3. Retainer (30) and seat.
4. Filter (29) over the pushrod eyelet and into the
power piston (41) (figure 27).
5. Retaining ring (28) onto the air valve pushrod as
sembly (32).
6
. Reaction bum per (27) and air valve spring (26).
7. Reaction piston (23) and reaction disc (22) into the
reaction body (25).
8
. Reaction body (25).
9. Reaction body retainer (24).
• Lubricate the inside diam eter of the secondary dia
20
phragm (
) lip, inside diam eter of the prim ary dia
phragm (16) lip and the secondary piston bearing
(18) with a thin layer of silicone grease.
10. Secondary diaphragm (20) into the secondary sup
2 1
port plate (
).
Figure 25 — Tandem Vacuum Booster Components
11. Secondary diaphragm (20) and support plate (21)
over the power piston assem bly (41) and pushrod
(32) (figure 28).
• Use J 28458 as a guide to protect the power
piston.
12. Secondary piston bearing (18) into the housing di
vider (19) with the flat surface of the bearing on the
same side as the six raised lugs on the divider.
13. Secondary piston bearing (18) and housing divider
(19) over the pow er piston assem bly (41) and
pushrod (32). Use J 28458 as a guide (figure 29).
14. Primary diaphragm (16) into the prim ary support
plate (17).
• Fold the prim ary diaphragm (16) up, away from the
prim ary support plate (17).
15. Primary diaphragm (16) and support plate (17) over
the power piston assem bly (41) and pushrod (32).
• Fold the primary diaphragm (16) back into position
and pull the outside edge of the diaphragm over the
formed flange of the housing divider (19).
F-05892