Subaru 2009 IMPREZA, Service Manual

Page: 2604 / 3619

BR-37
Air Bleeding
BRAKE
14.Air Bleeding
A: PROCEDURE
CAUTION:
• Do not let brake fluid come into contact with
the painted surface of the vehicle body. Wash
away with water immediately and wipe off if it is
spilled by accident.
• Avoid mixing brake fluid of different brands
to prevent fluid performance from degrading.
• Be careful not to allow dirt or dust to enter the
reservoir tank.
1. MASTER CYLINDER
NOTE:
• When the master cylinder is disassembled or the
reservoir tank is empty, bleed the master cylinder.
• If bleeding of the master cylinder is not neces-
sary, omit the following procedures, and perform
bleeding of the brake line. <Ref. to BR-37, BRAKE
LINE, PROCEDURE, Air Bleeding.>
1) Fill the reservoir tank of the master cylinder with
brake fluid.
NOTE:
While bleeding air, keep the reservoir tank filled
with brake fluid to prevent entry of air.
2) Disconnect the brake line at primary and sec-
ondary sides.
3) Wrap the master cylinder with a plastic bag.
4) Depress the brake pedal slowly and hold it.
NOTE:
On the model with brake assist mechanism, the fol-
lowing phenomena occur when the brake pedal is
depressed. However, those are not malfunction but
the phenomena that occur when the brake assist
mechanism functions properly.
• Brake feel is soft when brake pedal is depressed
hard or quicker than usual.
• A light crack is heard when brake pedal is de-
pressed hard or quicker than usual.
5) Plug the outlet plug with your finger, and then re-
lease the brake pedal.
6) Repeat the step 4) and 5) several times.
7) Remove the plastic bag.
8) Install the brake pipe to the master cylinder.
Tightening torque:
Model with ABS
15 N·m (1.5 kgf-m, 11.1 ft-lb)
Model with VDC
19 N·m (1.9 kgf-m, 14 ft-lb)
9) Bleed air from the brake line. <Ref. to BR-37,
BRAKE LINE, PROCEDURE, Air Bleeding.>
2. BRAKE LINE
1) When the master cylinder is disassembled or the
reservoir tank is empty, bleed the master cylinder
before bleeding the brake line. <Ref. to BR-37,
MASTER CYLINDER, PROCEDURE, Air Bleed-
ing.>
2) Fill the reservoir tank of the master cylinder with
brake fluid.
NOTE:
While bleeding air, keep the reservoir tank filled
with brake fluid to prevent entry of air.
3) Attach one end of the vinyl tube to the air bleeder
and the other end to the brake fluid container.
4) Depress the brake pedal several times, and hold
it.
5) Loosen the air bleeder screw to drain brake fluid.
Tighten the air bleeder quickly, and release the
brake pedal.
6) Repeat the steps 4) to 5) until there are no more
air bubbles in the vinyl tube.
BR-00090
BR-00091
BR-00087