LEXUS GS400 2000 Service Repair Manual

BR0JG±02
BR±14
± BRAKEPARKING BRAKE PEDAL
2122 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSTALLATION
Installation is in the reverse order of removal (See page BR±13).
HINT:
After the installation, check and adjust parking brake pedal travel (See page BR±11).

BR0JH±05
F01622
Anti±squeal ShimPad Support Plate
Anti±squeal Spring
Inner Pad
Outer Pad
Anti±squeal Shim
Inner Anti±squeal Shim
Pad Support Plate
Inner Anti±squeal Shim34 (350, 25)
N´m (kgf´cm, ft´lbf) : Specified torque
Disc brake grease
± BRAKEFRONT BRAKE PAD
BR±15
2123 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
FRONT BRAKE PAD
COMPONENTS

BR0JI±07
W00742
W00743
BR±16
± BRAKEFRONT BRAKE PAD
2124 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
REPLACEMENT
1. REMOVE FRONT WHEEL
2. INSPECT PAD LINING THICKNESS
Check the pad thickness through the caliper inspection hole
and replace the pads if they are not within the specification.
Minimum thickness: 1.0 mm (0.039 in.)
3. LIFT UP CALIPER
(a) Hold the sliding pin on the bottom and loosen the installa-
tion bolt.
(b) Remove the installation bolt.
(c) Lift up the caliper and suspend it securely.
HINT:
Do not disconnect the flexible hose from the caliper.
4. REMOVE 2 ANTI± SQUEAL SPRINGS
5. REMOVE 2 BRAKE PADS WITH 4 ANTI±SQUEAL
SHIMS
6. REMOVE 4 PAD SUPPORT PLATES
NOTICE:
The anti±squeal springs and support plates can be used
again provided that they have sufficient rebound, no de-
formation, cracks or wear, and have had all rust, dirt and
foreign particles cleaned off.
7. CHECK DISC THICKNESS AND RUNOUT
(See page BR±21)
8. INSTALL 4 PAD SUPPORT PLATES
9. INSTALL NEW PADS
NOTICE:
When replacing worn pads, the anti±squeal shims must be
replaced together with the pad.
(a) Install the 2 anti±squeal shims to each pad.
HINT:
Apply disc brake grease to both sides of the inner anti±squeal
shims (See page BR±15).
(b) Install the inner pad with the pad wear indicator plates fac-
ing downward.
(c) Install the outer pad.
NOTICE:
There should be no oil or grease adhering to the friction
surfaces of the pads or the disc.
(d) Install the 2 anti±squeal springs.

W00744
± BRAKEFRONT BRAKE PAD
BR±17
2125 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
10. INSTALL CALIPER
(a) Draw out a small amount of brake fluid from the reservoir.
(b) Press in the pistons with a hammer handle or similar im-
plement.
HINT:
If the pistons are difficult to push in, loosen the bleeder plug and
push in the pistons while letting some brake fluid escape.
(c) Install the caliper.
(d) Hold the sliding pin and torque the installation bolt.
Torque: 34 N´m (350 kgf´cm, 25 ft´lbf)
11. INSTALL FRONT WHEEL
Torque: 103 N´m (1,050 kgf´cm, 76 ft´lbf)
12. DEPRESS BRAKE PEDAL SEVERAL TIMES
13. CHECK THAT FLUID LEVEL IS AT MAX LINE

BR0JJ±07
F01623
11 (110, 8)
34 (350, 25)
Bleeder Plug

Gasket
Brake Caliper
Anti±squeal ShimPad Support Plate
Inner Pad
Inner Anti±squeal
ShimOuter PadAnti±squeal Spring
Boot
Piston Seal
PistonSet RingSliding Bushing Pad Support Plate
Sliding Pin

Dust Boot
Torque Plate
Disc
N´m (kgf´cm, ft´lbf): Specified torque
Lithium soap base glycol grease
Disc brake grease Non±reusable part


30 (310, 22)
118 (1,200, 87)
BR±18
± BRAKEFRONT BRAKE CALIPER
2126 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
FRONT BRAKE CALIPER
COMPONENTS

BR0JK±03
F01624
± BRAKEFRONT BRAKE CALIPER
BR±19
2127 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
REMOVAL
1. DISCONNECT FLEXIBLE HOSE
Remove the union bolt and 2 gaskets from the caliper, then dis-
connect the flexible hose from the caliper. Use a container to
catch brake fluid as it drains out.
Torque: 30 N´m (310 kgf´cm, 22 ft´lbf)
HINT:
At the time of installation, install the flexible hose lock securely
in the lock hole in the caliper.
2. REMOVE CALIPER
(a) Hold the sliding pin and loosen the 2 installation bolts.
Torque: 34 N´m (350 kgf´cm, 25 ft´lbf)
(b) Remove the 2 installation bolts.
(c) Remove the caliper from the torque plate.
3. REMOVE 2 ANTI±SQUEAL SPRINGS
4. REMOVE 2 BRAKE PADS WITH 4 ANTI±SQUEAL
SHIMS
5. REMOVE 4 PAD SUPPORT PLATES

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.

BR0JM±07
F01627
F01630
F01631
± BRAKEFRONT BRAKE CALIPER
BR±21
2129 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
INSPECTION
1. MEASURE PAD LINING THICKNESS
Using a ruler, measure the pad lining thickness.
Standard thickness: 11.0 mm (0.433 in.)
Minimum thickness: 1.0 mm (0.039 in.)
Replace the pad if the thickness is less than the minimum (the
1.0 mm slit is no longer visible), or if it shows signs of uneven
wear.
2. MEASURE DISC THICKNESS
Using a micrometer, measure the disc thickness.
Standard thickness: 32.0 mm (1.260 in.)
Minimum thickness: 30.0 mm (1.181 in.)
Replace the disc if the thickness of the disc is at the minimum
thickness or less. Replace the disc or grind it on a lathe if it is
scored or is worn unevenly.
3. MEASURE DISC RUNOUT
(a) Temporarily fasten the disc with the 3 hub nuts.
(b) Using a dial indicator, measure the disc runout at a posi-
tion 10 mm (0.39 in.) away from the out side edge.
Maximum disc runout: 0.05 mm (0.0020 in.)
If the disc's runout is maximum value or greater, check the bear-
ing play in the axial direction and check the axle hub runout
(See page SA±10). If the bearing play and axle hub runout are
not abnormal, adjust the disc runout or grind it on a ºOn±Carº
brake lathe.
4. IF NECESSARY, ADJUST DISC RUNOUT
(a) Remove the 2 bolts and torque plate.
(b) Remove the 3 hub nuts and disc. Turn the disc 1/5 turn
and reinstall the disc. Install and torque the 3 hub nuts.
Torque: 103 N´m (1,050 kgf´cm, 76 ft´lbf)
(c) Remeasure the disc runout. Make a note of the runout
and the disc's position on the hub.
(d) Repeat (b) until the disc has been installed on the 3 re-
maining hub positions.
(e) If the minimum runout recorded in (b) and (c) is less than
0.05 mm (0.0020 in.), install the disc in that position.
(f) If the minimum runout recorded in (b) and (c) is greater
than 0.05 mm (0.0020 in.), replace the disc and repeat
step 3.
(g) Install the torque plate and torque the 2 bolts.
Torque: 118 N´m (1,200 kgf´cm, 87 ft´lbf)

BR0JN±05
BR±22
± BRAKEFRONT BRAKE CALIPER
2130 Author: Date:
2000 LEXUS GS300/GS400 (RM718U)
REASSEMBLY
Reassembly is in the reverse order of disassembly (See page BR±20).
HINT:
Apply lithium soap base glycol grease to the parts indicated by the arrows (See page BR±18).