Lexus RX300 (MCU15). Service manual - part 175

BR072–05

BR0823

Contract

Expand

BR–52

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BRAKE

PARKING BRAKE

LEXUS RX300   (RM785E)

REASSEMBLY

Reassembly is in the reverse order of disassembly (See
page BR–50).
NOTICE:
Apply high temperature grease to the parts indicated by the
arrows (See page BR–49).
1.

ADJUST PARKING BRAKE SHOE CLEARANCE

(a)

Temporarily install the 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.

SETTLE PARKING BRAKE SHOES AND DISC

(a)

Depress the parking brake pedal with 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 for about 400 meters (0.25 mile) in this
condition.

(c)

Repeat this procedure 2 or 3 times.

3.

RECHECK AND ADJUST PARKING BRAKE PEDAL
TRAVEL (See page BR–8)

BR073–06

F13268

SST

SST

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BRAKE

PROPORTIONING VALVE (P VALVE)

BR–53

LEXUS RX300   (RM785E)

PROPORTIONING VALVE (P VALVE)

ON–VEHICLE INSPECTION

1.

INSTALL LSPV GAUGE (SST) AND BLEED AIR
SST

09709–29018

2.

BLEED AIR FROM FLUID PRESSURE GAUGE

3.

RAISE MASTER CYLINDER PRESSURE AND CHECK REAR CALIPER PRESSURE

Master cylinder fluid pressure

Rear brake caliper fluid pressure

2,942 kPa (30 kgf/cm

2

, 427 psi)

2,942 kPa (30 kgf/cm

2

, 427 psi)

7,845 kPa (80 kgf/cm

2

, 1,138 psi)

5,884 kPa (60 kgf/cm

2

, 853 psi)

If the rear brake caliper pressure is incorrect, replace the P valve assembly.
4.

REMOVE LSPV GAUGE (SST)
SST

09709–29018

5.

BLEED BRAKE SYSTEM (See page BR–4)

6.

CHECK FOR LEAKS

D09456

DLC3

Hand–held Tester

BR1KP–01

BR–54

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BRAKE

BRAKE ACTUATOR

LEXUS RX300   (RM785E)

BRAKE ACTUATOR

ON–VEHICLE INSPECTION

1.

CONNECT HAND–HELD TESTER

(a)

Connect the hand–held tester to the DLC3.

(b)

Start the engine and run it at idle.

(c)

Select the ACTIVE TEST mode on the hand–held tester.

HINT:
Please refer to the hand–held tester operator’s manual for fur-
ther details.
2.

INSPECT ACTUATOR MOTOR OPERATION

(a)

With the motor relay ON, check the actuator motor opera-
tion noise.

(b)

Turn the motor relay OFF.

(c)

Depress the brake pedal and hold it for about 15 seconds.
Check that the brake pedal cannot be depressed.

(d)

With the motor relay ON, check that the pedal does not
pulsate.

NOTICE:
Do not keep motor relay ON for more than 5 seconds con-
tinuously. When operating it continuously, set the interval
of more than 20 seconds.
(e)

Turn the motor relay OFF and release the brake pedal.

3.

INSPECT RIGHT FRONT WHEEL OPERATION

NOTICE:
Never turn ON the solenoid which is not described below.
(a)

With the brake pedal depressed, perform the following
operations.

(b)

Turn the SFRH and SFRR solenoid ON simulteneously,
and check that the pedal cannot be depressed.

NOTICE:
Do not keep solenoid ON for more than 10 seconds contin-
uously. When operating it continuously, set the interval of
more than 20 seconds.
(c)

Turn the SFRH and SFRR solenoid OFF simulteneously,
and check that the pedal can be depressed.

(d)

Turn the motor relay ON and check that the pedal returns.

NOTICE:
Do not keep motor relay ON for more than 5 seconds con-
tinuously. When operating it continuously, set the interval
of more than 20 seconds.
(e)

Turn the motor relay OFF and release the brake pedal.

4.

INSPECT OTHER WHEELS OPERATION

As in the same procedure, check the solenoids of other wheels.
HINT:
Left front wheel: SFLH, SFLR
Right rear wheel: SRRH, SRRR
Left rear wheel: SRLH, SRLR
5.

CLEAR DTC (See page DI–205)

BR1KQ–01

F13263

Brake Actuator
Assembly

Engine Coolant
Reservoir

5.4 (55, 48 in.·lbf)

PS Gear Tube Clamp

RH Fender Liner

Holder

Cushion

Holder

Cushion

Cushion

Actuator Bracket

N·m (kgf·cm, ft·lbf) : Specified torque

5.4 (55, 48 in.·lbf)

5.4 (55, 48 in.·lbf)

19 (195, 14)

19 (195, 14)

15 (155, 11)

Brake Actuator

15 (155, 11)

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BRAKE

BRAKE ACTUATOR

BR–55

LEXUS RX300   (RM785E)

COMPONENTS