Brakes - Disc Brake Squeal
46 Brakes squeal46 13 35
2017130/11
April 2, 2013
Supersedes Technical Service Bulletin Group 46 number 11-16 dated December 9, 2011 for reasons listed below.
Vehicle Information
Condition
Customer complains of brake squeal.
Technical Background
Not applicable.
Production Solution
Not applicable.
Service
Note:
Before proceeding with any of the following steps, check the overall condition of the brakes. If the following conditions exist, this TSB does not apply:
1. Brake discs or brake pads are close to or below their wear limit.
2. Rotors are covered with excessive rust due to long periods of the vehicle not being driven.
3. Foreign bodies between brake disc and brake pad, such as small stones, grit, or sand.
4. Rotors are severely grooved.
5. Aftermarket pads or rotors.
For vehicles within the New Vehicle Limited Warranty, Audi of America is requesting your cooperation in supplying us with technical information regarding this condition.
1. Verify the brake noise with a test drive.
2. Complete the Brake Noise Questionnaire.
3. Obtain a sound recording of the brake noise (a cell phone recording is OK as long as the noise can be clearly identified).
4. Email the questionnaire and sound recording to: alignment@audi.com.
Warning:
Never use compressed air to clean brake dust from a brake system.
Perform the braking sequence as follows:
Brake disc, cleaning
1. With careful consideration of the traffic situation, perform 2-3 ABS stops (e.g. from speeds above 50 MPH). Between each stop, please allow the brake components to cool. (Drive vehicle for more than 1 minute at speeds greater than 50MPH.)
2. If necessary, perform additional ABS stops allowing the brakes to cool between each stop (max. 5). Only proceed to the next step (Brake pad, cleaning) if the brake noise was not eliminated.
Brake pad, cleaning
1. With the wheels removed, mark the position of each brake pad to ensure reinstallation in the same position. Work on one brake at a time to avoid mixing up parts.
2. On some models, the front brake pads are glued to the brake caliper. Do not remove the pads for this procedure. Treat the pad as described in this TSB with it attached to the brake caliper. If these pads are unglued they must be replaced.
3. Some front/rear brake pads have an anti-vibration backing plate (non-sticky). Do not remove this type of backing plate.
4. Use Guided Functions to release the rear brake calipers for vehicles with Electronic Parking Brake (EPB). It is not necessary to re-adapt the parking brake for this procedure.
5. Clean face of the brake pad with sandpaper (Figure 2).
5. Clean all grooves with a suitable workshop hand tool (Figure 3).
6. Slightly chamfer edges of brake pads with a file (Figure 4).
Brake caliper, cleaning
Note:
The following steps require a thin coat of Plastilube Moly3(R) high temperature grease to be applied to various parts of the brakes. This grease must never come in contact with:
^ The braking surface of the brake pads or brake discs.
^ The caliper piston.
These areas must always be free of grease.
1. Thoroughly clean all contact points (Figure 5) where the brake pad backing plate makes contact with the brake caliper and/or the brake carrier.
Reassembly
1. Prior to reinstalling the brake pads, apply a thin coat of Plastilube Moly3(R) high temperature grease to contact points (Figure 5) where the brake pad backing plate makes contact with the brake caliper and/or the brake carrier.
2. For brake pads that have springs (common on rear brake pads), apply a thin coat of Plastilube Moly3(R) high temperature grease to the springs where they make contact with the brake caliper.
Warranty
Required Parts and Tools
Additional Information
All parts and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service manuals for the latest information.