Subaru XT 1988 Service Manual page 952

BRAKES 4-4
Fig. 11
Warning light
.,.
:
:
~
r------
a _ _ _ _ _ ... _ _ _ _ _ .. ,
I
I
Reed :
switch :
:
rI~
i
I
Permanent:
I
magnet :
_____________________ J
A17-154
Under normal conditions, the float remains above the reed
switch, and the line of the magnetic force from the permanent
magnet in the float is unable to activate the reed switch.
Therefore, the circuit is kept open, and the warning light
remains off. The float lowers as the brake fluid level lowers,
and if it falls below the specified fluid level [approx. 25 mm
(0.98 in) below the MAX level line], the reed switch will be
activated by the permanent magnet to close the circuit. In
this event, the warning light comes on and warns the driver of
a reduction of the brake fluid level.
However, the lamp may be lighted momentarily even when the
brake fluid surface is still above the specified level, if the
vehicle body tilts or swings largely.
Brake Booster
CHECK VALVE
The check valve is built into the vacuum hose. Its orientation
is indicated on the label attached to the vacuum hose.
1 - - - - - ,
: <ENGINE
I
1
(Stamp)
_ _ _ _ _ _ --l
)/-1
- I
, I)
[ . \ To engine" -
r:::IIl _ •
To brake
c.cr
booster
J-- __
'1
~'~_
I
~~
\ II
~-~
L4-1227
Fig. 12
5
Proportioning Valve
The proportioning vain for dual piping systems is adopted for
controlling the braking force.
To rear wheel cylinder (RH)
o
To rear wheel cylinder (LH) o
Stopper
piston
From master cylinder
(Secondary)
Fig. 13 Construction
Rear wheel 5,884 (60. 853)
cylinder flUid
o
From master cvlinder
(Primary) L4-913
Incase of failure /
in one circuit
'y
7,846 (80, 1. 1 38)1
pressure 3,923 (40. 569)-+-----,~
1,961 (20. 284) When both circuits
kPa (kg/cm
1
,
psi)
0(0,0)
1,961 3,923 5.884 7.846
(20, (40, (60. (80.
284) 569) 853) 1.138)
Master cylinder fluid pressure kPa (kg/em
1
,
psi)
In case of split point 3,923 kPa (40 kg/em'. 569 psi)
Rear wheel
cylinder fluid
pressure
7.846 (80. 1,138)
5,884 (60, 853)
3,923 (40. 569)
1,961 (20,284)
kPa (kg/cm l
,
psi)
When both circuits
1,961 3,923 5,884 7.846
(20. (40, (60, (80,
284) 569) 853) 1,138)
Master cylinder fluid pressure kPa (kg/cm
1
,
psi)
In case of split point 4,413 kPa (45 kg/cm
2
•
640 psi) L4-019
Fig. 14 Characteristic curve