Lexus RX300 (MCU15). Manual — part 167

BR06C–02

BR–20

–

BRAKE

BRAKE MASTER CYLINDER

LEXUS RX300 (RM785E)

INSPECTION

HINT:
Clean the disassembled parts with compressed air.
1.

INSPECT CYLINDER BORE FOR RUST OR SCORING

2.

INSPECT CYLINDER FOR WEAR OR DAMAGE

If necessary, clean or replace the cylinder.

BR1KL–01

F13279

Straight Pin

Upward

W03590

F13280

F13281

4.0 ± 1.5 mm
(0.157 ± 0.059 in.)

–

BRAKE

BRAKE MASTER CYLINDER

BR–21

LEXUS RX300 (RM785E)

REASSEMBLY

NOTICE:
Apply lithium soap base glycol grease to the rubber parts
indicated by the arrows (See page BR–14).
1.

PLACE CYLINDER IN VISE

2.

LHD and Europe RHD:
INSTALL SPRING AND NO. 2 PISTON

(a)

Install the spring and No. 2 piston into the cylinder body.

(b)

Push in the piston with a screwdriver, and install the
straight pin to the cylinder body.

HINT:

S

Tape the screwdriver tip before use.

S

Insert the piston with elliptic hole facing horizontally.

NOTICE:
Be careful not to damage the rubber lips on the pistons.
3.

RHD except for Europe:
INSTALL SPRINGS AND PISTONS

(a)

Install the 2 springs and pistons to the cylinder body.

(b)

Push in the piston with a screwdriver, and install the 2
straight pins to the cylinder body.

HINT:

S

Tape the screwdriver tip before use.

S

Insert the piston with elliptic hole facing vertically.

NOTICE:
Be careful not to damage the rubber lips on the pistons.
4.

LHD and Europe RHD:
INSTALL NO. 1 PISTON AND SPRING

(a)

Install the No. 1 piston and spring into the cylinder body.

(b)

Push in the piston by hand, install the snap ring with snap
ring pliers.

5.

INSTALL 2 GROMMETS

6.

INSTALL INLET UNION

(a)

Install the inlet union to the cylinder body.

(b)

LHD and Europe RHD:
Using a pin punch (5 mm) and hammer, drive in the pin.

(c)

RHD except for Europe:
Install the set screw.
Torque: 1.8 N·m (18 kgf·cm, 16 in.·lbf)

7.

LHD and Europe RHD:
INSTALL O–RING TO CYLINDER BODY

BR06E–05

BR–22

–

BRAKE

BRAKE MASTER CYLINDER

LEXUS RX300 (RM785E)

INSTALLATION

Installation is in the reverse order of removal (See page BR–16).
HINT:

S

Before installation, adjust length of brake booster push rod (See page BR–27).

S

After installation, fill the brake reservoir with brake fluid and bleed brake system (See page
BR–4), and check for leaks.

S

Check and adjust brake pedal (See page BR–8).

BR2237

BR06F–05

BR2238

GOOD

NO GOOD

1st

2nd

3rd

–

BRAKE

BRAKE BOOSTER ASSEMBLY

BR–23

LEXUS RX300 (RM785E)

BRAKE BOOSTER ASSEMBLY

ON–VEHICLE INSPECTION

1.

OPERATING CHECK

(a)

Depress the brake pedal several times with the engine off
and check that there is no change in the pedal reserve
distance.

(b)

Depress the brake pedal and start the engine. If the pedal
goes down slightly, operation is normal.

2.

AIR TIGHTNESS CHECK

(a)

Start the engine and stop it after 1 or 2 minutes. Depress
the brake pedal several times slowly.

If the pedal goes down farthest the 1st time, but gradually rises
after the 2nd or 3rd time, the booster is air–tight.
(b)

Depress the brake pedal while the engine is running, and
stop the engine with the pedal depressed. If there is no
change in the pedal reserve travel after holding the pedal
for 30 seconds, the booster is air–tight.