Subaru Legacy III (2000-2003 year). Manual - part 820

BR-38

BRAKE

BRAKE BOOSTER

• Lack of boosting action check

Turn off engine, and depress the brake pedal until the vacuum gauge reading indicates “0”. Then, check the
fluid pressure when brake pedal is depressed. The pressure must be greater than the standard value listed.

• Boosting action check

Set the vacuum gauge reading at 66.7 kPa (500 mmHg, 19.69 inHg) by running engine. Then, check the fluid
pressure when brake pedal is depressed. The pressure must be greater than the standard value listed.

Model

OUTBACK

Except OUTBACK

RHD without VDC

RHD with VDC, LHD

Brake pedal force

Fluid pressure

Fluid pressure

147 N (15 kgf, 33 lb)

686 kPa 

(7 kg/cm

2

, 100 psi)

588 kPa 

(6 kg/cm

2

, 85 psi)

588 kPa 

(6 kg/cm

2

, 85 psi)

294 N (30 kgf, 66 lb)

1,863 kPa 

(19 kg/cm

2

, 270 psi)

1,667 kPa 

(17 kg/cm

2

, 242 psi)

1,667 kPa 

(17 kg/cm

2

, 242 psi)

Model

OUTBACK

Except OUTBACK

RHD without VDC

RHD with VDC, LHD

Brake pedal force

Fluid pressure

Fluid pressure

147 N (15 kgf, 33 lb)

5,884 kPa

(60 kg/cm

2

, 853 psi)

5,688 kPa

(58 kg/cm

2

, 825 psi)

5,688 kPa

(58 kg/cm

2

, 825 psi)

294 N (30 kgf, 66 lb)

10,886 kPa

(111 kg/cm

2

, 1,578 psi)

9,702 kPa

(98.96 kg/cm

2

, 1,406.8 psi)

9,702 kPa

(98.96 kg/cm

2

, 1,406.8 psi)

BR-39

BRAKE

PROPORTIONING VALVE

10.Proportioning Valve

A: REMOVAL

1) Pull up parking brake lever, and block the tires.
2) Remove brake pipe from proportioning valve at
four places.
3) Remove proportioning valve from its bracket.

CAUTION:
Do not disassemble or adjust the proportioning 
valve. (The proportioning valve must be re-
placed as an assembly.)

B: INSTALLATION

1) Install proportioning valve to bracket.
2) Connect brake pipes correctly to proportioning
valve.
3) Bleed air, then check each joint of brake pipe for
oil leaks.

Tightening torque:

Proportioning valve to brake pipe flare nut:

15 N·m (1.5 kgf-m, 10.8 ft-lb)

Proportioning valve to bracket:

18 N·m (1.8 kgf-m, 13.0 ft-lb)

C: INSPECTION

1) Install oil pressure gauges to measure the mas-
ter cylinder fluid pressure (front wheel brake fluid
pressure) and rear wheel cylinder fluid pressure.
2) Bleed air from oil pressure gauges.
3) Check the master cylinder fluid pressure and
rear wheel cylinder fluid pressure.
The standard values are shown in Figure.

4) For the oil pressure in case of split point, refer to
“SPECIFICATIONS”.
<Ref. to BR-2, SPECIFICATIONS, General De-
scription.>

BR-00170

(1) Rear wheel cylinder fluid pressure: P3

(2) Master cylinder fluid pressure: P2

(3) In case of failure in one circuit

(4) When both circuits are normal

BR-00265

( 1 )

( 2 )

( 3 )

( 4 )

BR-40

BRAKE

BRAKE FLUID

11.Brake Fluid

A: INSPECTION

1) Check that brake fluid level remains between
“MIN” and “MAX”. If out of the specified range, refill
or drain fluid. If fluid level becomes close to “MIN”,
refill fluid.
2) Check fluid for discoloration. If fluid color has ex-
cessively changed, drain the fluid and refill with
new fluid.

B: REPLACEMENT

CAUTION:
• Be extremely careful not to spill brake fluid.
Brake fluid spilt on the vehicle body will harm
the painted surface; wash it off quickly if spilt.
• To always maintain the brake fluid character-
istics, replace the brake fluid according to
maintenance schedule or earlier than that when
used in severe condition.
• The FMVSS No. 116, fresh DOT3 or 4 brake
fluid must be used.
• Cover bleeder with waste cloth, when loosen-
ing it, to prevent brake fluid from being
splashed over surrounding parts.
• Avoid mixing different brands of brake fluid
to prevent degrading the quality of the fluid.
• Be careful not to allow dirt or dust to get into
the reservoir tank.

NOTE:
• During bleeding operation, keep the brake reser-
voir tank filled with brake fluid to eliminate entry of
air.
• Brake pedal operation must be very slow.
• For convenience and safety, two people should
do the work.
• The amount of brake fluid required is approxi-
mately 500 m

2

 (16.9 US fl oz, 17.6 Imp fl oz) for to-

tal brake system.
1) Either jack-up vehicle and place a safety stand
under it, or lift up vehicle.
2) Remove both front and rear wheels.
3) Draw out the brake fluid from master cylinder
with syringe.
4) Refill reservoir tank with recommended brake
fluid.

Recommended brake fluid:

FMVSS No. 116, fresh DOT3 or 4 brake fluid

5) Install one end of a vinyl tube onto the air bleeder
and insert the other end into a container to collect
the brake fluid.

CAUTION:
Brake fluid replacement sequence; (A) Front 
right 

→

→

→

→

 (B) Rear left 

→

→

→

→

 (C) Front left 

→

→

→

→

 (D) Rear 

right

6) Instruct your co-worker to depress the brake
pedal slowly two or three times and then hold it de-
pressed.
7) Loosen bleeder screw approximately 1/4 turn
until a small amount of brake fluid drains into con-
tainer, and then quickly tighten screw.
8) Repeat steps 6) and 7) above until there are no
air bubbles in drained brake fluid and new fluid
flows through vinyl tube.

NOTE:
Add brake fluid as necessary while performing the
air bleed operation, in order to prevent the tank
from running short of brake fluid.
9) After completing the bleeding operation, hold
brake pedal depressed and tighten screw and in-
stall bleeder cap.

Tightening torque (Bleeder screw):

8 N·m (0.8 kgf-m, 5.8 ft-lb)

10) Bleed air from each wheel cylinder using the
same procedures as described in steps 6) through
7) above.

(1) Master cylinder

(2) Hydraulic unit

(3) Proportioning valve

BR-00087

BR-00089

( 3 )

( 1 )

( 2 )

( A )

( B )

( C )

( D )

BR-41

BRAKE

BRAKE FLUID

11) Depress brake pedal with a force of approxi-
mately 294 N (30 kgf, 66 lb) and hold it there for ap-
proximately 20 seconds. At this time check pedal to
see if it shows any unusual movement.
Visually inspect bleeder screws and brake pipe
joints to make sure that there is no fluid leakage.
12) Install wheels, and drive vehicle for a short dis-
tance between 2 to 3 km (1 to 2 miles) to make sure
that brakes are operating properly.