LEXUS GS400 2000 Service Repair Manual

BR0K8±09
F06044Non±reusable part


Gasket
Hydraulic Brake Booster
Assembly
13 (130, 9)
End PadBrake Fluid Level Warning
ConnectorReturn Spring
No. 7 Heater to Register DuctNo. 1 Under Cover No. 1 Safety Pad
15 (155, 11)
15 (155, 11)
15 (155, 11)
15 (155, 11)
N´m (kgf´cm, ft´lbf) : Specified torquePin
Clip BR±48
± BRAKEHYDRAULIC BRAKE BOOSTER
2156 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
COMPONENTS

F06045
Reservoir Set Screw
Hydraulic Brake Booster
Oil Pressure
Sensor
No. 1 Accumulator
BracketNo. 2
Accumulator
Bracket
No. 1 Pump
Bracket
Actuator No. 1 TubeAccumulator

O±ring
Spring
Silencer Tube Grommet
No. 2 Piston
No. 1 PistonSnap Ring
BootClevis Reservoir
Cap
No. 2 Pump
Bracket Sleeve
Collar
Booster Pump Motor
Cushion Washer Actuator Hose
15 (155, 11)
54 (550, 36)
1.7 (17.5, 15.2 in.´lbf)
81 (830, 60)
Non±reusable part


Cushion Cushion
Collar
Cushion
25 (260, 19)
N´m (kgf´cm, ft´lbf) : Specified torqueSpacer

O±ring
Clamp

Wire Harness
± BRAKEHYDRAULIC BRAKE BOOSTER
BR±49
2157 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)

BR0K9±04
F06046
SST
F01655
SST
F06047
BR±50
± BRAKEHYDRAULIC BRAKE BOOSTER
2158 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
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
F01657Pin
± BRAKEHYDRAULIC BRAKE BOOSTER
BR±51
2159 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
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
± BRAKEHYDRAULIC BRAKE BOOSTER
2160 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
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
± BRAKEHYDRAULIC BRAKE BOOSTER
BR±53
2161 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
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.

BR0YW±01
F04504
BA
A: 20 mm (0.791 in.)
B: 30 mm (1.18 in.) BR±54
± BRAKEHYDRAULIC BRAKE BOOSTER
2162 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
DISPOSAL
DISPOSAL METHOD OF ACCUMULATOR
(a) Follow the procedures described below and drain the
high pressure gas from the accumulator.
(b) Place the accumulator in a vise, cover it with a cloth over
a saw then cut the accumulator body slowly.
CAUTION:
Never cut at a stretch.
(c) When the outer body of the accumulator is cut, gas dis-
charges.

BR0KC±03
F02900
C
AB
E
D
F02901
mm (in.)
1.1
(0.0433)
Clearance
ºAº
0.1
(0.0039)
Clearance ºBº 0.1
(0.0039) 1.1
(0.0433)
Clearance ºEº Clearance
ºDº
mm (in.) 0.095
(0.0374)
0.3
(0.0118)
0.25
(0.0098) 0.65
(0.0256)mm (in.) mm (in.)
± BRAKEHYDRAULIC BRAKE BOOSTER
BR±55
2163 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
REASSEMBLY
Reassembly is in the reverse order of disassembly
(See page BR±51).
INSTALL ACCUMULATOR BRACKET
When installing the accumulator bracket, adjust to ensure that
clearance (A, B, D and E) shown in the illustration on the left
crresponds to each value in the graphs below and are within the
C range, using a thickness gauge.
C Range: 0.1 ± 0.4 mm (0.004 ± 0.016 in.)

BR0KD±05
BR±56
± BRAKEHYDRAULIC BRAKE BOOSTER
2164 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSTALLATION
Installation is in the reverse order of removal (See page BR±50).
HINT:

After installation, fill the brake reservoir with brake fluid and bleed brake system (See page BR±4).

Check for leaks.

BR0K1±07
F02813
Front Speed Sensor
5.0 (51, 44 in.´lbf)
5.0 (51, 44 in.´lbf)
8.0 (82, 71 in.´lbf)
N´m (kgf´cm, ft´lbf) : Specified torque
± BRAKEFRONT SPEED SENSOR
BR±57
2165 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
FRONT SPEED SENSOR
COMPONENTS