Lexus SC300 / Lexus SC400. Service manual - part 249

MASTER CYLINDER ASSEMBLY

BR0EH–05

1. APPLY 

LITHIUM 

SOAP 

BASE 

GLYCOL 

GREASE 

TO

RUBBER PARTS INDICATED BY ARROWS

2. INSTALL 

PISTONS

NOTICE: Be careful not to damage the rubber lips on the pis-

tons.

(a)  Insert the 2 pistons straight in, not at an angle.

NOTICE: If inserted at an angle, there is a possibility that the

cylinder bore could be damaged.

(b) Push 

in 

the piston with a screwdriver and install the snap ring

with snap ring pliers.
HINT: Tape the screwdriver tip before use.

3.

 w/ TRAC:
INSTALL NO. 1 PISTON STOPPER BOLT
Using a screwdriver, push the piston in all the way and install
the No. 1 piston stopper bolt over a new gasket.

Torque: 10 N

⋅

m (100 kgf

⋅

cm, 7 ft

⋅

lbf)

4.

 INSTALL NO. 2 PISTON STOPPER BOLT
Using a screwdriver, push the piston in all the way and install
the No. 2 piston stopper bolt over a new gasket.

Torque: 10 N

⋅

m (100 kgf

⋅

cm, 7 ft

⋅

lbf)

5. 

INSTALL 2 GROMMETS

6. INSTALL 

RESERVOIR

(a)  Install the strainer to the reservoir.
(b)  Push the reservoir onto the cylinder.
(c)  Install the set screw while pushing on the reservoir.

Torque: 1.7 N

⋅

m (17.5 kgf

⋅

cm, 15.2 in.

⋅

lbf)

7. 

INSTALL RESERVOIR CAP

(a) Align 

the matchmark on the reservoir cap with the matchmark

on the “open” side of reservoir.

(b)  Push down on the reservoir cap and turn it clockwise until it

locks.

(c)  Check that the matchmark on the reservoir cap is now

aligned with the matchmark on the “close” side of the
reservoir.

BR–16

–

BRAKE SYSTEM

MASTER CYLINDER

8. 

INSTALL MASTER CYLINDER BOOT
With the UP mark on the master cylinder boot facing up-
wards, install the cylinder boot on the master cylinder.

MASTER CYLINDER INSTALLATION

BR0EJ–05

1.  ADJUST LENGTH OF BRAKE BOOSTER PUSH ROD

BEFORE INSTALLING MASTER CYLINDER
(See page

 

BR–19

)

2. 

INSTALL MASTER CYLINDER
Install the master cylinder and a new gasket on the brake
booster with 3 nuts.

Torque: 13 N

⋅

m (130 kgf

⋅

cm, 9 ft

⋅

lbf)

3. 

CONNECT BRAKE LINES
Using SST, connect the brake lines to the master cylinder.
Torque the union nuts.
SST 09023–00100

Torque: 12 N

⋅

m (125 kgf

⋅

cm, 9 ft

⋅

lbf)

4. 

CONNECT LEVEL WARNING SWITCH CONNECTOR

5. FILL 

BRAKE 

RESERVOIR WITH BRAKE FLUID AND

BLEED BRAKE SYSTEM
(See page 

BR–8

)

6. w/ TRAC:
BLEED TRAC SYSTEM
(See page 

BR–10

)

7. 

CHECK FOR FLUID LEAKAGE

8. 

CHECK AND ADJUST BRAKE PEDAL
(See page 

BR–7

)

–

BRAKE SYSTEM

MASTER CYLINDER

BR–17

BRAKE BOOSTER

BRAKE BOOSTER REMOVAL

BR0EK–03

1. w/ 

TRAC:

DRAIN OUT HIGH PRESSURE FLUID

(a) Connect a vinyl tube to the bleeder plug of the TRAC

actuator, then loosen the bleeder plug with the ignition switch
in the OFF position.
CAUTION: The fluid is under high pressure, and could
spray out with great force, so exercise caution.

(b)  Tighten the plug when fluid stops flowing out.

2. 

REMOVE FOLLOWING PARTS:

•

Master cylinder

(See page

 BR–12

)

•

w/ TRAC:

TRAC pump assembly
(See page 

BR–162

)

•

Vacuum hose

•

Clip and return spring

BR–18

–

BRAKE SYSTEM

BRAKE BOOSTER

3. 

REMOVE BRAKE BOOSTER

(a)  Remove the booster installation nuts.
(b)  Remove the booster and gasket.

BRAKE BOOSTER INSTALLATION

BR03Z–08

1. 

INSTALL BRAKE BOOSTER

(a)  Install the booster and gasket.
(b)  Install and torque the booster installation nuts.

Torque: 12 N

⋅

m (125 kgf

⋅

cm, 9 ft

⋅

lbf)

(c) Insert 

the clevis pin into the clevis and brake pedal, and install

the clip to the clevis pin.

(d)  Install the pedal return spring.

2. 

ADJUST LENGTH OF BOOSTER PUSH ROD

(a)  Install the gasket on the master cylinder.
(b)  Set the SST on the gasket, and lower the pin until its tip

slightly touches the piston.
SST 09737–00010

(c)  Turn the SST upside down, and set it on the booster.

SST 09737–00010

(d)  Measure the clearance between the booster push rod and

pin head (SST).

Clearance:

0 mm (0 in.)

(e)  Adjust the booster push rod length until the push rod lightly

touches the pin head.
HINT: When adjusting the push rod, depress the brake pedal
enough so that the push rod sticks out.

3. 

INSTALL FOLLOWING PARTS:

•

Vacuum hose

•

Master cylinder

(See page 

BR–12

)

•

w/ TRAC:

TRAC pump assembly
(See page 

BR–162

)

–

BRAKE SYSTEM

BRAKE BOOSTER

BR–19