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Canada - Brakes - Brake Actuator Abnormal Noise

Bulletin
TSB2536

Issue Date
November 9, 2007

Title
BRAKE ACTUATOR ABNORMAL NOISE

Component
BRAKES

Models
'06 - '07 RX 400h

INTRODUCTION:

Some customers may complain of a squawk, chirp, or honk type noise when pressing and/or releasing the brake pedal. A new brake actuator bleed procedure has been developed to reduce the frequency of this noise.

APPLICABLE VEHICLES:
- 2006 - 2007 model year RX 400h vehicles.






REQUIRED SSTS:






WARRANTY INFORMATION:

BLEED PROCEDURE:

1. Connect the Techstream to DLC3 and turn the ignition to the "ON" position.
2. Check to confirm NO Diagnostic Trouble Codes (DTCs) have been stored. System Select > ABS/VSC/TRAC
3. With the ignition switch turned OFF, remove approximately 100 cc of brake fluid from the brake reservoir so that fluid level is at the MIN level.
4. Raise the front the vehicle by about 55 -- 65 cm (21.5 -- 25.5 in.) and engage the parking brake. For correct jack positions, refer to the repair Manual within E-TAS / TIS library:

Division: Lexus
Model: RX 400h
Year: 2006 or 2007
Service Category: General
Section: Introduction
Keyword: Introduction: Repair Instruction: Vehicle Lift and Support Locations

5. Turn the ignition switch to the ON position.
6. Perform the accumulator ZERO DOWN procedure.
A. Go to the following menu on Techstream:
System Select > ABS/VSC/TRAC > ECB Utility > ZERO DOWN
B. Follow the on-screen procedure.
C. Wait for the buzzer sound.

7. Activate the "Actuator Pattern" by going to the following menu on Techstream:
System Select > ABS/VSC/TRAC > Active Test > Actuator Air Bleeding Pattern
Perform this Actuator Air Bleeding Pattern ON/OFF Procedure 10 times.

NOTE:
When active testing, ACTUATOR AIR BLEEDING Pattern "ON" vehicle will perform a self test and then display "OFF" when completed (usually takes approximately 30 - 70 seconds to cycle from "ON" to "OFF").


8. Perform the Accumulator Zero Down Procedure (step 6) and Actuator Air Bleeding Pattern ON/OFF Procedure (step 7) 2 more times.
9. Perform the Accumulator Zero Down Procedure (step 6) 1 more time.
10. Verify there is NO abnormal noise.
- If there is NO noise present, go to step 11.
- If the noise is still present:
- If occurrence frequency was reduced, repeat steps 5 - 9 one more time and confirm noise.
- If occurrence frequency has NOT changed, change the actuator assembly and confirm the noise has been reduced.

Refer to the Repair Manual within E-TAS / TIS library:
- Division: Lexus
- Model: RX 400h
- Year: 2006 or 2007
- Service Category: Brake
- Section: Brake Control/Dynamic Control System
- Keyword: Brake Control: Brake Actuator: Removal
- Keyword: Brake Control: Brake Actuator: Installation

11. With the ignition switch ON, fill the brake reservoir tank to the MAX level.

Perform Health Check and confirm the condition is corrected.
Check for any NEW DTC codes. If any DTC codes are present, then repair according to the Repair Manual.

NOTE:
Issue of this Technical Service Bulletin is to ensure that proper repair information is available.
IT DOES NOT CONSTITUTE AN AUTHORIZATION FOR REPAIR. Normal provisions of the formal warranty policy, as applicable, will apply.