ABS/TCS - Knock/Click When Brake Pedal Is Depressed
L-SB-0178-09December 2, 2009
Brake Actuator Knock Noise
Service Category
Brake
Section
Brake Control/Dynamic Control System
Market
USA
Applicability
Introduction
Some LS 460/460L and LS 600h vehicles may exhibit a knocking and/or clicking type noise from the brake actuator during light brake application when coming to a stop or when depressing the brake pedal while the vehicle is stopped. An improved brake actuator has been introduced to correct this condition.
Refer to the video link below for an example of the knock/click noise condition:
LS Brake Knock/Click Noise Example
Warranty Information
APPLICABLE WARRANTY
^ This repair is covered under the Lexus Comprehensive Warranty. This warranty is in effect for 48 months or 50,000 miles, whichever occurs first, from the vehicle's in-service date.
^ Warranty application is limited to occurrence of the specified condition described in this bulletin.
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 Section 1 of TSIB L-SB-0069-09. "Squawk/Bark Type Noise from Brake Actuator.
3. Replace the brake actuator assembly.
Refer to the Technical Information System (TIS) applicable model and model year Repair Manual:
4. Press the "Engine Start/Stop" button to the ignition ON position and perform brake bleed starting with Section 2 of TSIB L-SB-0069-09. "Squawk/Bark Type Noise from Brake Actuator".
5. Road test the vehicle to verify proper brake operation and that the noise has been eliminated.