Operation CHARM: Car repair manuals for everyone.

Canada - Brakes - Brake Actuator Knock/Clicking Noise

Bulletin
TSB2758

Issue Date
December 22, 2009

Title
BRAKE ACTUATOR KNOCK NOISE

Component
BRAKES

Models
'07-'10 LS460; '08-'10 LS600h

INTRODUCTION:

Some LS460/460L and LS600h vehicles may exhibit a knocking and/or clicking type noise from the brake actuator during light brake application when:
- coming to a stop.
- when depressing the brake pedal while the vehicle is stopped.

An improved brake actuator has been introduced to correct this condition.

Refer to the attached video link for an example of the knock/click noise condition.






LS Brake Knock/Click Noise Example






APPLICABILITY:






WARRANTY INFORMATION:






PARTS INFORMATION:






REQUIRED TOOLS & EQUIPMENT:

REPAIR PROCEDURE:

1. Confirm the knocking and or clicking noise is coming from the brake actuator during light brake application or when depressing the brake pedal while the vehicle is stopped.
2. Prior to removing the brake actuator, zero down the accumulator pressure following the TSB2659, "Squawk/Bark Type Noise from Brake Actuator".
3. Replace the brake actuator assembly.

Refer to the Repair Manual within E-TAS / TIS library:

- Division: Lexus
- Model: LS460
- Year: 2007/ 2008/ 2009/ 2010
- Service Category: Brake
- Section: Brake Control/Dynamic Control System
- Keyword: Brake Control: Brake Actuator: Removal / Installation

- Division: Lexus
- Model: LS600h
- Year: 2008/ 2009/ 2010
- Service Category: Brake
- Section: Brake Control/Dynamic Control System
- Keyword: Brake Control: Brake Actuator: Removal / Installation

IMPORTANT
After a NEW brake actuator is installed, DO NOT connect accumulator connectors and press the "Engine Start/Stop" button to the ignition ON position. If the connectors are plugged in and the ignition is turned ON, pressure will be built up in the accumulator.


4. Press the "Engine Start/Stop" button to the ignition ON position and perform brake bleed starting with TSB2659, "Squawk/Bark Type Noise from Brake Actuator".
5. Road test the vehicle to verify proper brake operation and that the noise has been eliminated.

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.