Tuesday, August 28, 2018

******** Audi S4 Quattro Sedan (8K2) V6-3.0L SC (CCBA) Technical DIAGNOSIS AND REPAIR # 461223 Date: 120618


Brakes - Brake Pulsation Diagnostic Information



46 Brake pulsation diagnostic guidelines



46 12 23



2022584/3



June 18, 2012.



Supersedes Technical Service Bulletin Group 46 number 12 - 19 dated January 18, 2012 for reasons listed below.



Affected Vehicles



46



Condition



Brake pulsation.



Technical Background



Brake pulsation may be related to:



^ Rust buildup and/or brake pad marks on discs.



^ This may be due to moisture exposure or prolonged periods of the vehicle not being driven.



^ This may affect vehicles at PDI or those already delivered to customers.



^ Brake disc thickness variation.



^ Thermal distortion of brake discs.



^ Worn brake pads and discs.



^ Faulty suspension components (ball joints, tie rods, bushing, etc.).



^ Imbalance of wheels and tires.



Production Solution



Not applicable.



Service



Diagnosis



^ Verify all complaints with a test drive.



^ Complete the Brake Pulsation Service Tree (attached). Fill it out as you work on the vehicle and attach a copy to the repair order.



^ Also check the following points:



^ At what speed does the pulsation start? At what speed does the pulsation stop?



^ With how much pedal pressure (light / medium / high) can the pulsation be created?



^ Where is the pulsation observed? (steering wheel / brake pedal / seat / front of the vehicle)



^ Roll the vehicle in the established speed range without braking and check for vibrations.



^ If necessary, clean the disc brakes of any corrosion or residues.



^ Always use the attached Brake Disc/Pad Measurement Form (announced in Warranty Circular AWA 05-06) to document brake disc and pad



thickness. Attach a completed copy to the repair order.



Rust buildup and/or brake pad marks on brake discs



Every effort must be made to avoid replacing brake discs if they can be cleaned off by performing ABS stops as described in the "Diagnose" portion



of Brake Pulsation Service Tree.



Tip: Rust buildup due to incomplete Inventory Maintenance Procedures as outlined in the Inventory Maintenance Checklist is not covered under



Warranty.



Thermal distortion of brake discs



Blue burn marks on brake discs are evidence of extremely high thermal loading of brake system. This results in permanent damage to brake discs



47



and pads.



If vehicle is driven aggressively, brakes must be cooled down by driving around with minimal braking before parking vehicle for extended periods of



time.



Tip: This type of damage cannot be repaired under warranty.



Worn brake pads and discs



As brake discs and pads wear, their dampening effects are reduced.



Faulty suspension components and/or imbalance of wheels and tires



Inspect condition of these components. All values must be within factory specifications.



Make sure only OEM components are on vehicle.



Warranty



This TSB is informational only and not applicable to any Audi warranty.



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.