2000 LEXUS GS400 parking brake

BR0JA±09
BR±2
± BRAKETROUBLESHOOTING
2110 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
TROUBLESHOOTING
PROBLEM SYMPTOMS TABLE
Use the table below to help you find the cause of the problem. The numbers indicate the priority of the likely
cause of the problem. Check each part in order. If necessary, replace these parts.
SymptomSuspect AreaSee page
Low pedal or spongy pedal
6. Fluid leaks for brake system
7. Air in brake system
8. Piston seals (Worn or damaged)
9. Hydraulic brake booster (Faulty)DI±516
BR±4
BR±18
BR±27
BR±38
Brake drag
1. Brake pedal freeplay (Minimum)
2. Parking brake pedal travel (Out of adjustment)
3. Parking brake wire (Sticking)
4. Parking brake (Shoe clearance out of adjustment)
5. Pad (Cracked or distorted)
6. Piston (Stuck)
7. Piston (Frozen)
8. Tension or return spring (Faulty)
9. Hydraulic brake booster (Faulty)BR±9
BR±11
±
BR±37
BR±15
BR±24
BR±18
BR±27
BR±18
BR±27
BR±33
BR±38
Brake pull
1. Piston (Stuck)
2. Pad (Cracked or distorted)
3. Piston (Frozen)
4. Disc (Scored)
5. Pad (Cracked or distorted)
6. Hydraulic brake booster (Faulty)BR±18
BR±27
BR±15
BR±24
BR±18
BR±27
BR±18
BR±27
BR±15
BR±24
BR±38
Hard pedal but brake inefficient
1. Fluid leaks for brake system
2. Air in brake system
3. Pad (Worn)
4. Pad (Cracked or distorted)
5. Pad (Oily)
6. Pad (Glazed)
7. Disc (Scored)
8. Hydraulic brake booster (Faulty)DI±516
BR±4
BR±15
BR±24
BR±15
BR±24
BR±15
BR±24
BR±15
BR±24
BR±18
BR±30
BR±38

± BRAKETROUBLESHOOTING
BR±3
2111 Author: Date:
2000 LEXUS GS300/GS400 (RM718U) Noise from brakes
1. Pad (Cracked or distorted)
2. Installation bolt (Loose)
3. Disc (Scored)
4. Pad support plate (Loose)
5. Sliding pin (Worn)
6. Pad (Dirty)
7. Pad (Glazed)
8. Tension or return spring (Faulty)
9. Anti±squeal shim (Damaged)
10.Shoe hold±down spring (Damaged)BR±15
BR±24
BR±15
BR±24
BR±18
BR±27
BR±18
BR±18
BR±15
BR±24
BR±15
BR±24
BR±33
BR±18
BR±27
BR±33
Noise from hydraulic brake booster
(Abnormal pump motor operation noise)Accumulator bracket clearance (Out or adjustment)BR±56
Brake warning light lights up*1
(Parking brake pedal released)
1. Brake fluid level
2. Hydraulic brake booster power supply system (Faulty)BR±38
Brake warning light lights up and brake warning buzzer sounds*2Hydraulic brake booster power supply system (Faulty)BR±38
ABS warning light lights up*31. Anti±lock brake system (Faulty)
2. Hydraulic brake booster power supply system (Faulty)
BR±38
*1, *3: The light may stay on for about 60 seconds after the engine has been started. It is normal if it goes
out after a while.
*
2, *3: Depressing the brake pedal repeatedly may turn on the warning light and buzzer. It is normal if the
light goes out and the buzzer stops sounding after a few seconds.
*
3: While ABS warning light is ON, both VSC warning light and VSC OFF indicator light come on.

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)

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.