Subaru IMPREZA 2002 Service Manual page 417

AIR BLEEDING
is
BRAKE
CAUTION:
Brake fluid replacement sequence; (A) Front
right
right
(6) Rear left
+
(C) Front left
+
(D) Rear
I
S4M0475A
(1) Master cylinder
(2) Hydraulic unit
(3) Proportioning valve
3) Slowly depress the brake pedal and keep it de-
pressed. Then, open the air bleeder to discharge
air together with the fluid.
Release the air bleeder for 1 to 2 seconds.
Next, with the bleeder closed, slowly release the
brake pedal.
Repeat these steps until there is no more air bub-
bles in the vinyl tube.
Allow 3 to 4 seconds between two brake pedal op-
erations.
CAUTION:
Cover the bleeder with waste cloth, when loos-
ening it, to prevent brake fluid from being
splashed over surrounding parts.
NOTE:
Brake pedal operating must be very slow.
4) Tighten the air bleeder securely when no air bub-
bles are visible.
Air bleeder tightening torque:
8 N.m (0.8 kgf-m, 5.8 ft-lb)
5 ) Perform these steps for the brakes connecting to
the secondary chamber of master cylinder, first,
and then for the ones connecting to primary cham-
ber. With all procedures completed, fully depress
the brake pedal and keep it in that position for ap-
proximately 20 seconds to make sure that there is
no
leak evident in the entire system.
6) Check the pedal stroke.
While the engine is idling, depress the brake pedal
with a 490 N (50 kgf, 110 Ib) load and measure the
distance between the brake pedal and steering
wheel. With the brake pedal released, measure the
distance between the pedal and steering wheel
again. The difference between the two measure-
ments must be more than specified.
S4M0476A
\
(1) Steering wheel
(2) Toe board
Specified pedal stroke:
Without ABS
90 mm (3.54 in)
With ABS
95 mm (3.74 in)
When depressing brake pedal with a 490 N
(50 kg, 110 lb) load.
7) If the distance is more than specified, there is a
possibility that air is in the brake line. Bleed the
brake line until pedal stroke meets the specifica-
tion.
8) Operate the hydraulic control unit in the se-
quence control mode. (With ABS)
<Ref. to ABS-I 1, ABS Sequence Control.>
9) Recheck the brake stroke.
10) If the distance is more than specified, there is a
possibility air is in the inside of the hydraulic unit.
Repeat above steps 2) to 9) until pedal stroke
meets the specification.
11) Add brake fluid to the required level (MAX. lev-
el) of reservoir tank.
12) As a final step, test run the vehicle at low speed
and apply brakes relatively hard 2 to 3 times to en-
sure that brakes provide normal braking action on
all four wheels without dragging and uneven brak-
ing.
BR-47