Brakes Squeak/Squeal On Light To Moderate Application
SI B 34 03 09Brakes
September 2009
Technical Service
This Service Information bulletin replaces B34 01 07, B34 08 08 and B34 09 08.
SUBJECT
Brake Squeal from Pad Wear Sensor
MODEL
E82, E88 (1 Series) up to 12/08
E90, E91, E92, E93 (3 Series) up to 12/08
E60, E61 (5 Series) up to 5/09
E63, E64 (6 Series) up to 5/09
E65, E66 (7 Series) up to 2/07
E70 (X5) up to 1/09
E71 (X6) up to 1/09
SITUATION
Depending on the driving conditions, the occasional brake squeak and/or squeal is normal. The condition listed in this bulletin occurs during all light to moderate brake applications and is caused by contact between the brake pad wear sensor and the brake rotor/disc. This situation can occur on the front or rear axle brakes.
CAUSE
The geometry of the brake wear sensor, combined with individual driving habits, can result in a particular wear pattern which causes a squeaking and/or squealing noise whenever the brakes are applied with light to moderate force.
CORRECTION
Road test the vehicle to determine the source of the noise. If the noise is coming from the brake system, inspect the brake pad wear sensor of the affected axle. If the sensor is in contact with the rotor/disc, remove the sensor and drive the vehicle.
If the noise is not eliminated, further diagnosis is required to determine the cause of the noise.
If the noise is eliminated, replace the brake pads and wear sensor of the affected axle.
Measure and record the thickness of each of the brake pads to be replaced. Refer to the Warranty section of this bulletin for important information regarding the correct usage of warranty defect codes based on brake pad thickness.
Refer to the appropriate Repair Instructions:
RA 34 11 000 "Removing and installing/replacing brake linings on both front disc brakes"
RA 34 21 200 "Removing and installing/replacing brake linings on both rear brake discs"
PARTS INFORMATION
For the latest part numbers of brake components, please refer to EPC/ETK. Only replace parts on the affected axle as listed under CORRECTION in this bulletin.
WARRANTY INFORMATION