Lexus GS300/400 (2000 year). Manual - part 109

BR0K9–04

F06046

SST

F01655

SST

F06047

BR–50

–

BRAKE

HYDRAULIC BRAKE BOOSTER

2158

REMOVAL

NOTICE:

Before starting the work, make sure that the ignition
switch is OFF and depress the brake pedal more than
40 times.

As high pressure is applied to the brake actuator tube
No. 1, never deform it.

Until the work is over, do not turn the ignition switch
ON.

1.

DRAW OUT FLUID WITH SYRINGE

NOTICE:
Do not let brake fluid remain on a painted surface. Wash it
off immediately.
2.

REMOVE NO. 1 UNDER COVER (See page 

BO–88

)

3.

REMOVE END PAD AND NO. 1 SAFETY PAD

4.

REMOVE NO. 7 HEATER TO REGISTER DUCT

5.

DISCONNECT BRAKE LINES

Using SST, disconnect the 4 brake lines.

SST

09023–00100

Torque: 15 N·m (155 kgf·cm, 11 ft·lbf)

6.

DISCONNECT LEFT FRONT WHEEL BRAKE LINE

Using SST, disconnect the left front wheel brake line from the
flexible hose.

SST

09023–00100

Torque: 15 N·m (155 kgf·cm, 11 ft·lbf)

7.

REMOVE 2 BRAKE LINE CLAMPS

8.

DISCONNECT LEVEL WARNING SWITCH CONNEC-
TOR

9.

DISCONNECT 4 CONNECTORS

10.

REMOVE PEDAL RETURN SPRING, CLIP AND CLE-
VIS PIN

11.

REMOVE HYDRAULIC BRAKE BOOSTER ASSEMBLY

(a)

Loosen the lock nut, then remove the clevis and lock nut.
Torque: 25 N·m (260 kgf·cm, 19 ft·lbf)

(b)

Remove the 4 booster installation nuts.
Torque: 13 N·m (130 kgf·cm, 9 ft·lbf)

(c)

Remove the booster assembly and gasket.

BR0YV–02

F06048

SST

SST

F06961

F01657

Pin

–

BRAKE

HYDRAULIC BRAKE BOOSTER

BR–51

2159

DISASSEMBLY

1.

PLACE HYDRAULIC BRAKE BOOSTER IN VISE

Using SST, set the hydraulic brake booster in vise.

SST

09630–00014 (09631–00142),
09950–60010 (09951–00180, 09951–00190)

2.

REMOVE RESERVOIR AND GROMMETS

(a)

Remove the reservoir cap.

(b)

Remove the 3 set screws and pull out the reservoir.
Torque: 1.7 N·m (17.5 kgf·cm, 15.2 in.·lbf)

(c)

Remove the 3 grommets.

3.

REMOVE CYLINDER BOOT

4.

REMOVE OIL PRESSURE SENSOR

Using 30 mm deeper socket wrench and remove the oil pres-
sure sensor, spacer and O–ring.

Torque: 81 N·m (830 kgf·cm, 60 ft·lbf)

5.

REMOVE PISTONS

(a)

Pressing the piston in with a screwdriver, use a pin or an
equivalent to push the snap ring from the hole in the body
then remove it with another screwdriver.

(b)

Remove the No. 1 and No. 2 piston, pulling straight out,
not at an angle.

NOTICE:

If pulled out and installed at an angle, there is a possi-
bility that the cylinder bore could be damaged.

At the time of reassembly, be careful not to damage
the rubber lips on the pistons.

6.

DISCONNECT ACTUATOR HOSE

7.

REMOVE 3 BOLTS, 2 HANGERS AND CLAMP

F02809

SST

F06962

Cloth

F06963

SST

Cloth

BR–52

–

BRAKE

HYDRAULIC BRAKE BOOSTER

2160

8.

REMOVE BRAKE ACTUATOR TUBE NO. 1

Using SST, remove the brake actuator tube No. 1.

SST

09023–00100

Torque: 15 N·m (155 kgf·cm, 11 ft·lbf)

9.

REMOVE BOOSTER PUMP AND ACCUMULATOR

(a)

Remove the 4 screws and  wire harness.

HINT:
At the time of installation, please refer to the following item.
Replace the used wire harness with new one.
(b)

Using 5 mm socket hexagon wrench, remove the 3 bolts,
No. 1 accumulator bracket, No. 2 accumulator bracket,
booster pump and accumulator with the No. 1 pump
bracket.

(c)

Remove the bolt and No. 1 pump bracket, and remove the
2 washers, 3 cushions, 2 collars and sleeve.

(d)

Remove the 2 bolts and No. 2 pump bracket.

10.

PLACE BOOSTER PUMP IN VISE

Place the booster pump with a cloth shown in the illustration on
the left.

11.

REMOVE ACCUMULATOR FROM BOOSTER PUMP

(a)

Using SST, remove the accumulator.
SST

09318–12010

Torque: 54 N·m (550 kgf·cm, 36 ft·lbf)

(b)

Remove the silencer tube, spring and O–ring.

NOTICE:
Ensure no foreign matter enters the pump.

BR120–01

F06051

1

2

–

BRAKE

HYDRAULIC BRAKE BOOSTER

BR–53

2161

INSPECTION

INSPECT HYDRAULIC BRAKE BOOSTER PUMP MOTOR
OPERATION
(a)

Connct the positive (+) lead from the battery to terminal
1 of pump motor, and the negative (–) lead to terminal 2.

(b)

Check that the pump motor operation.