LEXUS GS400 2000 Service Repair Manual

BR0JX±06
F04516
Pin
18 (185, 13)
Shoe Return Spring
104 (1,065, 77)
Rear Disc Brake
Assembly
Front Shoe

C±washer
Shim
Parking Brake shoe
Lever
Rear Shoe
Shoe Strut
SpringShoe Hold±down Spring
(Color: Pink)
Adjuster
Cup
Tension Spring
Shoe Hold±down Spring
(Color: Blue)
DiscPlug
High temperature grease
N´m (kgf´cm, ft´lbf) : Specified torque
± BRAKEPARKING BRAKE
BR±33
2141 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
PARKING BRAKE
COMPONENTS

BR0JY±03
F01647
F01648
F01649
F01650
F01651
BR±34
± BRAKEPARKING BRAKE
2142 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
DISASSEMBLY
1. REMOVE REAR WHEEL
Torque: 103 N´m (1,050 kgf´cm, 76 ft´lbf)
2. REMOVE REAR DISC BRAKE ASSEMBLY
(a) Remove the 2 mounting bolts and remove the disc brake
assembly.
Torque: 104 N´m (1,065 kgf´cm, 77 ft´lbf)
(b) Suspend the disc brake securely and so the hose is not
stretched.
3. REMOVE DISC
(a) Release the parking brake pedal.
(b) Place matchmarks on the disc and rear axle hub.
(c) Remove the disc.
HINT:

If the disc cannot be removed easily, turn the shoe adjust-
er until the wheel turns freely.

If there are no matchmarks, temporarily install the disc,
then measure the disc runout and install the disc in posi-
tion (See page BR±30).
4. REMOVE SHOE RETURN SPRINGS
Using needle±nose pliers, remove the 2 shoe return springs.
5. REMOVE SHOE STRUT WITH SPRING
HINT:
At the time of reassembly, install the strut with the spring facing
forward.
6. REMOVE FRONT SHOE AND ADJUSTER
(a) Slide out the front shoe and remove the shoe adjuster.
(b) Disconnect the tension spring and remove the front shoe.
(c) Remove the 2 cups, shoe hold±down spring and pin.
7. REMOVE REAR SHOE AND TENSION SPRING
(a) Slide out the rear shoe.
(b) Remove the tension spring from the rear shoe.
(c) Disconnect the parking brake cable from the parking
brake shoe lever.
(d) Remove the 2 cups, shoe hold±down spring and pin.

BR0JZ±03
BR5332
F06409
BR5333
Shim
Clearance
± BRAKEPARKING BRAKE
BR±35
2143 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. INSPECT DISASSEMBLED PARTS
Inspect the disassembled parts for wear, rust or damage.
2. MEASURE BRAKE SHOE LINING THICKNESS
Using a ruler, measure the thickness of the shoe lining.
Standard thickness: 2.5 mm (0.098 in.)
Minimum thickness: 1.0 mm (0.039 in.)
If the lining thickness is at the minimum thickness or less, or if
there is severe and uneven wear, replace the brake shoe.
3. MEASURE BRAKE DISC INSIDE DIAMETER
Using a brake drum gauge or equivalent, measure the inside di-
ameter of the disc.
Standard inside diameter: 190 mm (7.48 in.)
Maximum inside diameter: 191 mm (7.52 in.)
Replace the disc if the inside diameter is at the maximum value
or more.
Replace the disc or grind it with a lathe if the disc is scored or
worn unevenly.
4. INSPECT PARKING BRAKE SHOE LINING AND DISC
FOR PROPER CONTACT
Apply chalk to the inside surface of the disc, then grind down
the brake shoe lining to fit. If the contact between the disc and
the brake shoe lining is improper, repair it using a brake shoe
grinder or replace the brake shoe assembly.
5. MEASURE CLEARANCE BETWEEN PARKING
BRAKE SHOE AND LEVER
Using a feeler gauge, measure the clearance.
Standard clearance: Less than 0.35 mm (0.0138 in.)
If the clearance is not within the specification, replace the shim
with one of the correct size.
Thickness mm (in.)Thickness mm (in.)
0.3 (0.012)0.9 (0.035)
0.6 (0.024)±

R15060
BR±36
± BRAKEPARKING BRAKE
2144 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
6. IF NECESSARY, REPLACE SHIM
(a) Using a screwdriver, remove the C±washer and shim.
(b) Install the correct size shim.
(c) Install a new C±washer.
(d) Remeasure the clearance.

BR0K0±03
F02913
Contract
± BRAKEPARKING BRAKE
BR±37
2145 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
REASSEMBLY
Reassembly is in the reverse order of disassembly (See
page BR±34).
HINT:
Apply high temperature grease to the parts indicated by the ar-
rows (See page BR±33).
1. ADJUST PARKING BRAKE SHOE CLEARANCE
(a) Temporarily install the 3 hub nuts.
(b) Remove the hole plug.
(c) Turn the adjuster and expand the shoes until the disc
locks.
(d) Return the adjuster 8 notches.
(e) Install the hole plug.
2. SETTLING PARKING BRAKE SHOES AND DISC
(a) Depress the parking brake pedal with a force of 147 N (15
kgf, 33 lbf).
(b) Drive the vehicle at about 50 km/h (31 mph) on a safe, lev-
el and dry road.
(c) Drive the vehicle for about 400 meters (0.25 mile) in this
condition.
(d) Repeat this procedure 2 or 3 times.
3. CHECK AND ADJUST PARKING BRAKE PEDAL
TRAVEL (See page BR±11)

F02911
SST
Effort Gauge
SST
BR0K7±04
BR±38
± BRAKEHYDRAULIC BRAKE BOOSTER
2146 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
HYDRAULIC BRAKE BOOSTER
ON±VEHICLE INSPECTION
1. CHECK HYDRAULIC BRAKE BOOSTER FLUID PRES-
SURE CHANGE
(a) Inspect the battery positive voltage.
Battery positive voltage: 10 ± 14 V
(b) Turn the ignition switch OFF, depress the brake pedal
more than 40 times.
(c) Install LSPV gauge (SST) and brake pedal effort gauge,
bleed air.
SST 09709±29018
(d) When booster does not operate.
Depress the brake pedal and check fluid pressure.
At 245 N (25 kgf, 55 lbf):
Front brake pressureRear brake pressure
1,470 kPa (15 kgf/cm2, 213 psi)
or more0 kPa (0 kgf/cm2, 0 psi)
At 343 N (35 kgf, 77 lbf):
Front brake pressureRear brake pressure
2,059 kPa (21 kgf/cm2, 299 psi)
or more0 kPa (0 kgf/cm2, 0 psi)
(e) When booster operates.
(1) Turn the ignition switch ON and wait until the pump
motor has stopped.
(2) Depress the brake pedal and check fluid pressure.
At 49 N (5 kgf, 11 lbf):
Front brake pressureRear brake pressure
794 ± 1,814 kPa
(8.1 ± 18.5 kgf/cm2, 115 ± 263 psi)
961 ± 2,148 kPa
(9.8 ± 21.9 kgf/cm2, 139 ± 311 psi)
At 98 N (10 kgf, 22 lbf):
Front brake pressureRear brake pressure
3,442 ± 5,011 kPa
(35.1 ± 51.1 kgf/cm2, 499 ± 727 psi)
3,923 ± 5,698 kPa
(40 ± 58.1 kgf/cm2, 569 ± 826 psi)
At 147 N (15 kgf, 33 lbf):
Front brake pressureRear brake pressure
5,629 ± 7,845 kPa
(57.4 ± 80 kgf/cm2, 816 ± 1,138 psi)
6,237 ± 8,640 kPa
(63.6 ± 88.1 kgf/cm2, 905 ± 1,253 psi)
At 196 N (20 kgf, 44 lbf):
Front brake pressureRear brake pressure
8,002 ± 10,591 kPa
(81.6 ± 108 kgf/cm2, 1,161± 1,536 psi)
8,718 ± 11,572 kPa
(88.9 ± 118 kgf/cm2, 1,264 ± 1,678 psi)

D01827
± BRAKEHYDRAULIC BRAKE BOOSTER
BR±39
2147 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
2. IN CASE OF USING LEXUS HAND±HELD TESTER:
INSPECT HYDRAULIC BRAKE BOOSTER OPERA-
TION
(a) Inspect the battery positive voltage.
Battery positive voltage: 10 ± 14 V
(b) Turn the ignition switch OFF, depress the brake pedal
more than 40 times.
(c) Check that the brake pedal becomes heavy to depress.
If the pedal does not become to be heavy to depress, check and
replace the brake line and hydraulic brake booster.
(d) Turn the ignition switch ON, check the pump motor opera-
tion noise.
If the pump motor does not operate, check and replace the wire
harness and pump motor (See page BR±53).
(e) Connect the LEXUS hand±held tester.
(1) Connect the LEXUS hand±held tester to the DLC3.
(2) Turn the ignition switch ON.
(3) Select the ºACTIVE TESTº mode on the LEXUS
hand±held tester.
HINT:

Please refer to the LEXUS hand±held tester operator's
manual for further details.

To protect the solenoids, hand±held tester turns OFF au-
tomatically 2 secs. after every solenoid has been turned
ON.
(f) Inspect the front TRAC & VSC solenoid operation.
(1) Select ºSA1º and ºSA2º on the LEXUS hand±held
tester.
(2) With ºSA1º and ºSA2º turned ON simultaneously
with the LEXUS hand±held tester, depress the
brake pedal with stable force and check that the
pedal cannot be depressed.
HINT:
To protect the solenoids, LEXUS hand±held tester turns OFF
automatically 2 sec. after every solenoid has been turned ON.
If the pedal can be depressed, replace the hydraulic brake
booster.
NOTICE:
When operating it continuously, set the interval of more
than 20 seconds.
(3) Once, release the brake pedal.

BR±40
± BRAKEHYDRAULIC BRAKE BOOSTER
2148 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(4) When the solenoids are OFF, after depressing the
brake pedal again and check that the brake pedal
can be depressed.
If the pedal cannot be depressed, replace the hydraulic brake
booster.
(g) Inspect the front ABS solenoid operation.
(1) Select ºSFRHº and ºSFLHº on the LEXUS hand±
held tester.
(2) With ºSFRHº and ºSFLHº turned ON simultaneously
with the LEXUS hand±held tester, depress the
brake pedal with stable force and check that the
brake pedal cannot be depressed.
HINT:
To protect the solenoids, hand±held tester turns OFF automati-
cally 2 sec. after every solenoid has been turned ON.
If the pedal can be depressed, replace the hydraulic brake
booster.
(3) Once, release the brake pedal when the solenoids
are OFF, check that the brake pedal can be de-
pressed.
If the pedal cannot be depressed, replace the hydraulic brake
booster.
(4) Once, release the brake pedal. After depressing
and holding the brake pedal with stable force, turn
the SFRH and SFRR solenoids ON simultaneously.
HINT:
To protect the solenoids, hand±held tester turns OFF automati-
cally 2 sec. after every solenoid has been turned ON.
(5) When the solenoids are OFF, check that the brake
pedal can be depressed.
If the pedal cannot be depressed, replace the hydraulic brake
booster.
(6) Once, release the brake pedal. After depressing
and holding the brake pedal with stable force, turn
the SFLH and SFLR solenoids ON simultaneously.
HINT:
To protect the solenoids, hand±held tester turns OFF automati-
cally 2 sec. after every solenoid has been turned ON.
(7) When the solenoids are OFF, check that the brake
pedal can be depressed.
If the pedal cannot be depressed, replace the hydraulic brake
booster.
(h) Jack up and support the vehicle.
(i) Release the parking brake pedal.
(j) Shift the shift lever to ºNº position and check that the rear
wheels by rotating them by hand.
(k) Inspect the rear TRAC & VSC solenoid operation.
(1) Select the ºSA3º and ºSTRº on the LEXUS hand±
held tester.

± BRAKEHYDRAULIC BRAKE BOOSTER
BR±41
2149 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(2) Turn the ºSA3º and ºSTRº ON simultaneously with
the LEXUS hand±held tester, and check that the
rear wheels by does not rotate by hand.
HINT:
When rotating the wheel fast, the fail±safe function is activated
and judgement cannot be made properly. So rotate the wheel
as slowly as possible.
If the rear wheels rotate, replace the hydraulic brake booster.
(3) Turn the ºSA3º and ºSTRº OFF simultaneously, and
check that the rear wheels by rotating them by
hand.
HINT:

To protect the solenoids, LEXUS hand±held tester turns
OFF automatically 2 sec. after every solenoid has been
turned ON.

When rotating the wheel fast, the fail±safe function is acti-
vated and judgement cannot be made properly. So rotate
the wheel as slowly as possible.
NOTICE:
When operating it continuously, set the interval of more
than 20 secs.
If the rear wheels stop, replace the hydraulic brake booster.
(l) Inspect the right rear ABS solenoid.
(1) Select the ºSA3º, ºSTRº and ºSRRHº, on the LEXUS
hand±held tester.
(2) Turn the ºSA3º, ºSTRº and ºSRRHº ON simulta-
neously with the LEXUS hand±held tester, and
check that the right rear wheel by rotating it by hand.
HINT:

To protect the solenoids, LEXUS hand±held tester turns
OFF automatically 2 sec. after every solenoid has been
turned ON.

When rotating the wheel fast, the fail±safe function is acti-
vated and judgement cannot be made properly. So rotate
the wheel as slowly as possible.

When solenoid is OFF, the wheel might stop temporarily.
However if the wheel rotates again, the function works
normally.
If the rear wheels stop, replace the hydraulic brake booster.
(3) Turn the ºSA3º, ºSTRº and ºSRRHº OFF, and check
that the right rear wheel by rotating it by hand.
HINT:

To protect the solenoids, LEXUS hand±held tester turns
OFF automatically 2 sec. after every solenoid has been
turned ON.

When rotating the wheel fast, the fail±safe function is acti-
vated and judgement cannot be made properly. So rotate
the wheel as slowly as possible.
If the right rear wheel stop, replace the hydraulic brake booster.

BR±42
± BRAKEHYDRAULIC BRAKE BOOSTER
2150 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
(4) Depress the pedal with stable force, then turn the
ºSRRHº and ºSRRRº ON simultaneously.
(5) When the solenoids are ON, check that the right
rear wheel by rotating it by hand.
(m) Inspect the left rear ABS solenoid operation.
(1) Select the ºSA3º, ºSTRº and ºSRLHº on the LEXUS
hand±held tester.
(2) Turn the ºSA3º, ºSTRº and ºSRLHº ON with LEXUS
hand±held tester, and check that the left rear wheel
by rotating it by hand.
HINT:
When rotating the wheel fast, the fail±safe function is activated
and judgement cannot be made properly. So rotate the wheel
as slowly as possible.
If the rear wheels stop, replace the hydraulic brake booster.
(3) Turn the ºSA3º, ºSTRº and ºSRLHº OFF and check
that the left rear wheel by rotating it by hand.
HINT:

To protect the solenoids, LEXUS hand±held tester turns
OFF automatically 2 sec. after every solenoid has been
turned ON.

When rotating the wheel fast, the fail±safe function is acti-
vated and judgement cannot be made properly. So rotate
the wheel as slowly as possible.

When solenoid is OFF, the wheel might stop temporarily.
However if the wheel rotates again, the function works
normally.
If the left rear wheel stop, replace the hydraulic brake booster.
(4) Depress the pedal with stable force, then turn the
ºSRLHº and ºSRLRº ON simultaneously.
HINT:
To protect the solenoids, LEXUS hand±held tester turns OFF
automatically 2 sec. after every solenoid has been turned ON.
(5) When the solenoids are ON, check that the left rear
wheel by rotating it by hand.
HINT:
When rotating the wheel fast, the fail±safe function is activated
and judgement cannot be made properly. So rotate the wheel
as slowly as possible.
(n) Lower the vehicle.
(o) Disconnect the LEXUS hand±held tester.