Civic L4-1.3L Hybrid (2008)
Brake Master Cylinder: All Technical Service Bulletins
Brakes - Short, Buzzy Grunt Sound Upon Pedal Application
08-057
September 26, 2008
Applies To:
2006-08 Civic Hybrid - ALL
Brake System Makes a Short, Buzzy Grunt When the Brake Pedal Is Pressed
(Supersedes 08-057, dated August 23, 2008, to update the information marked by the black bar)
SYMPTOM
The advanced hydraulic booster (AHB) system intermittently makes a pronounced short, buzzy grunt when the brake pedal is pressed.
NOTE:
This bulletin does not address the faint hiss that is characteristic of normal operation when pressing the brake pedal. There is also a low buzz that
occurs about every other pedal application, which is the normal cycling of the AHB power unit as it maintains internal hydraulic pressure.
PROBABLE CAUSE
Brake fluid pulsation within the AHB causes a short buzzy grunt noise when the brake pedal is pressed.
CORRECTIVE ACTION
Replace the master cylinder and servo unit assembly (servo set).
PARTS INFORMATION
Master Cylinder and Servo Unit Assembly (servo set):
P/N 01469-SNC-315, H/C 9047242
WARRANTY CLAIM INFORMATION
In warranty:
The normal warranty applies.
Out of warranty:
Any repair performed after warranty expiration may be eligible for goodwill consideration by the District Parts and Service Manager or your Zone
Office. You must request consideration, and get a decision, before starting work.
DIAGNOSIS
The engine needs to be running to duplicate this noise when applying the brake pedal. The noise can be very intermittent (possibly taking weeks to
duplicate), which may make duplicating the complaint difficult.
If you are viewing this service bulletin on ISIS and your computer has sound, click on the icons above to hear examples of the short, buzzy grunt. You
may choose to have your customer also listen to the sound clip to verify the noise.
