Vacuum Boosters; Single Diaphragm Vacuum Booster - Chevrolet 1988 Light Duty Truck Repair Manual

Delco-M oraine Vacuum Boosters have a build date on a
small paper label glued onto the front housing. The first
digit indicates the year it was built (a 5 means 1985 or a

SINGLE DIAPHRAGM VACUUM BOOSTER

R em o ve or D isco nn ect (F ig u re 20)
Tool Required:
J 23456 Power Brake Booster Disassembly
and Reassembly Fixture
1. Boot (1) and silencer (2).
2. Vacuum check valve (3) and grom m et (4).
3. Front housing seal (5).
• Scribe a mark across the front and rear housings to
aid in assembly.
• Use J 23456 to apply force in a counter clockwise
direction to unlock the housings (figure
4. Return spring (9) and power piston group.
6
5. Power piston bearing (
6
. Reaction body retainer (25).
7. Piston rod (10) and reaction retainer (11).
8
. Filter (12) using an awl or sim ilar tool.
9. Power piston and pushrod assem bly (16).
-41
— 42
43
. — 44
__ 55
-45
-46
47
/4 8
Figure 19— Bendix Master Cylinder Com ponents

VACUUM BOOSTERS

6
2 1 ).
) from the rear housing (7).
41. Cover
42. Diaphragm
43. F ilte r
44. R eservoir
45. C om pe n satin g Valve Seal
46. Valve Poppet
47. Spring
48. S econdary Spring
49. S econdary P iston
50. P iston Return S pring
51. Prim ary Piston
52. Snap Ring
53. Body
54. B o lts
55. O-Ring
means 1986). The last digits indicate the day it was built
(271 means the 271st day of production year).
• Grasp the outside edge of the diaphragm sup­
p o rt (15) and d ia p h ra g m (14). H o ld th e
pushrod (19) down against a hard surface.
• Use a slight force or impact to dislodge the
diaphragm retainer (13).
10 Diaphragm (14) from the diaphragm support (15).
.
I9
In sp ect
All parts for corrosion, nicks, cracks, cuts, scoring,
distortion or excessive wear. Replace parts as nec­
essary.
Use crocus cloth to polish away minor corrosion of
the housings or diaphragm support.
Clean
All parts in clean denatured alcohol.
— Do not immerse the power piston and pushrod
assem bly in alcohol.
Dry with unlubricated compressed air.
BRAKES 5-9
F-00775