Table of Contents
Advertisement
AUXI LIARY BRAKE SYSTEM
DESCRI PTION
Fig
.
5·70.
Se
rv
o
cylinde
r
1. Vacuum inlel
9. Rear vacuum chamber
2. Sealing ring
10.
Rela i ner
3.
Fronl vacuum chamber
11. Diaphragm
4. Fronl lhrusl rod
12.
Guide housing
5. Retainer
13.
Valve pislon seat
6. Diaphragm
14.
Sealing ring
7. Sealing ring
15.
Seal
8. Guide sleeve
16. Guide
S ERV O CYLI NO ER
This is a mechanical tandem -type servo device located
between the brake pedal and the master cylinder, see
Fig.
5-6.
Due to the servo cylinder, which is assisted
by vacuum from the engine induction manifoid, less
pedal pressure is required when braking. The con
-
struction as weil as the designation and location of
the parts are shown in Fig.
5-70.
The servo cylinder
function as follows.
17.
Relainer
18. Filter
19.
Silencer
20.
Sealing ring
21.
Cylinder
22.
Return spring
23.
End
24. Reac1ion disc
25.
Valve pi ston
33. Valve spring
26.
Slop washer
34. Return spring
27.
Wa sher
35.
Rubber cover
28
.
Guide housing
36. Washer
29.
Valve guide
37.
Rear thrust rod
30. End
31. Valve plale
32.
Altaching
screw
When the system is at rest, the parts of the servo
cylinder are in the position shown in Fig. 5-71. The
thrust rod spring holds the thrust rod and the valve
piston flexibly connected to it pressed to the right.
Movement is limited by the stop plate. In this posi-
tion, the valve plunger keeps the valve lifted from
the seat in the guide housing, and this closes the all'
channel and opens the vacuum channe!. Thus an
Max. partiai vacuum
_
Atmosph
e
ric pressure
Fig
. 5·71.
Rest
pos
iti
o
n
VOLVO
103202
5
:
29
Advertisement
Table of Contents
