Lexus SC300 / Lexus SC400. Manual — part 251

2. REMOVE

CALIPER

(a) Hold the sliding pin and loosen the 2 installation bolts.
(b) Remove the 2 installation bolts.
(c) Remove the caliper from the torque plate.

3.

REMOVE FOLLOWING PARTS:

(a) 2 anti–squeal springs
(b) 2 brake pads

CALIPER DISASSEMBLY

BR043–0B

1.

REMOVE CYLINDER BOOT SET RINGS AND CYLINDER
BOOT
Using a screwdriver, remove the 2 cylinder boot set rings and
cylinder boots from the caliper.

2. REMOVE

PISTONS

(a) Place

a

piece of cloth or similar article between the piston and

the caliper.

(b) Use compressed air to remove the pistons from the caliper.

CAUTION: Do not place your fingers in front of the piston when

using compressed air.

3. REMOVE

PISTON

SEALS

Using a screwdriver, remove the piston seal from the caliper.

BR–32

–

BRAKE SYSTEM

FRONT BRAKE (SC400)

4.

REMOVE SLIDING PINS AND DUST BOOTS

(a) Remove the 2 sliding pins from the torque plate.

(b) Using a screwdriver and hammer, tap out the 2 dust boots.

FRONT BRAKE COMPONENTS
INSPECTION AND REPAIR

BR044–08

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 pad’s thickness is at the minimum
thickness or less, or if the pad has severely uneven wear.

2.

MEASURE DISC THICKNESS
Using a micrometer, measure the disc thickness.

Standard thickness:

32 mm (1.260 in.)

Minimum thickness:

30 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.

–

BRAKE SYSTEM

FRONT BRAKE (SC400)

BR–33

3.

MEASURE DISC RUNOUT
Using a dial indicator, measure the disc runout at a position
10 mm (0.39 in.) from the outside edge.

Maximum disc runout:

0.05 mm (0.0020 in.)

If the disc’s runout is at the maximum value or greater, check
the bearing play in the axial direction and check the axle hub
runout (See page SA–30). If the bearing play and axle hub
runout are not abnormal, adjust the disc runout.

4.

IF NECESSARY, ADJUST DISC RUNOUT

(a) Remove the 2 bolts and torque plate from the knuckle.
(b) Remove the hub nuts and the disc. Reinstall the disc 1/5 of

a turn round from its original position on the hub. Install and
torque the hub nuts.

Torque: 103 N

⋅

m (1,050 kgf

⋅

cm, 76 ft

⋅

lbf)

Remeasure the disc runout. Make a not of the runout and
disc’s position on the hub.

(c) Repeat (b) until the disc has been install on the 3 remaining

hub position.

(d) If

the minimum runout recorded in (b) and (c) is less than 0.05

mm (0.0020 in.), install the disc in that position.

(e) 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.

(f) Install the torque plate and torque the 2 bolts.

Torque: 118 N

⋅

m (1,200 kgf

⋅

cm, 87 ft

⋅

lbf)

CALIPER ASSEMBLY

BR045–0B

1. APPLY

LITHIUM

SOAP

BASE

GLYCOL

GREASE

TO

PARTS INDICATED WITH ARROWS

BR–34

–

BRAKE SYSTEM

FRONT BRAKE (SC400)

2.

INSTALL DUST BOOTS AND SLIDING PINS

(a) Using a 19 mm socket and hammer, tap in 2 new dust boots

into the torque plate.

(b) Confirm that the metal plate portion of the dust boot fits

snugly in the torque plate.

(c) Insert 2 sliding pins into the torque plate.

NOTICE: Insert the sliding pin with sliding bushing A into the

upper part, and insert the sliding pin with sliding bushing B

into the lower part.

3.

INSTALL PISTON SEALS AND PISTONS IN CALIPER

4.

INSTALL CYLINDER BOOTS AND CYLINDER BOOT SET
RINGS

CALIPER INSTALLATION

BR046–0C

1. INSTALL

FOLLOWING

PARTS:

(a) 2 brake pads
(b) 2 anti–squeal springs

–

BRAKE SYSTEM

FRONT BRAKE (SC400)

BR–35