Subaru SVX 1992 Manual page 848

4-4 [M5B5]
BRAKES
Position (No electric current : OFF)
Master cylinder and wheel cylinder passages are connected.
0
1 rrooooooo
To wheel cylinder
From
ILT
"
master cylinder
0000000
D000
0000
Magnet valve
1
To reservoir
~2
Second position (Half electric current < 1 .9 - 2.3
A > : ON)
All passages are closed .
U
To wheel wheel cylinder
cylinder f---J
D°ooo0O~ra
From
~ master cylinder
tD000 00~]wo
Y~/.6 0 0
Magnet valve
To reservoir
(3) Third positio
(Full electric current < 4.8 ^- 6.0 A > : ON)
Wheel cylinder and reservoir passages are connected.
To wheel cylinder ~-- ---~
KD O o 0 0 oQ V
From
master cylinder
0
0 0 DO(]
1 - .10(1
Magnet valve
To reservoir
B4-040
Fig. 28
1) During normal braking
When the brake pedal is depressed, fluid pressure is
delivered from master cylinder 1) to magnet valve
via F-valve © while moving the ball up . Since current
does not flow through the magnet valve, fluid pressure
is delivered to wheel cylinder ® so that normal braking
force occurs .
Fluid pressure delivered to the F-valve © also reaches
outlet valve ® which is sealed by the ball .
Accumulator 01 has its spring set to act by high fluid
pressure, and not by normal fluid pressure . When cur-
rent does not flow through the magnet valve, the outlet
port is sealed so that the oil passage to reservoir 5 is
not linked .
When the brake pedal is released, master cylinder 1~
fluid pressure will decrease . Wheel cylinder © pressure
will then return to the master cylinder 11) while pushing
the ball of check valve 3) . At this point, F-valve © is
moved up by the ball to prevent wheel cylinder
pressure from returning to the master cylinder 1@ .
However, when master cylinder 1@ pressure drops
below approximately 981 kPa (10 kg/cm', 142 psi), the
F-valve ©'s return spring is moved to the left to push
the ball up . This allows a slight amount of residual
pressure (applied to check valve 3)) to be delivered to
wheel cylinder ® via magnet valve ® .
When the brake pedal is slightly released while the ABS
is operating, excess wheel cylinder fluid pressure re-
turns to the master cylinder via check valve 3) so that
wheel cylinder fluid pressure is balanced with master
cylinder fluid pressure .
During the time the excess wheel cylinder fluid pressure
returns to the master cylinder, the driver may feel a
pedal "kickback".
This is not an indication of a problem .
18