There are 9 owner-reported brakes complaints for the 2002 Audi S4in NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
THE BRAKES BOOST/VACUUM ASSIST LINE CHECK VALVE CRACKS APART INTO TWO PIECES. THIS CAUSES THE TOTAL LOSS OF THE POWER ASSISTED BRAKE SYSTEM IN THE CAR AND SUBSEQUENTLY MAKES IT VERY HARD TO STOP THE VEHICLE. THERE IS NO WARNING ABOUT THE PENDING LOSS OF BRAKES. ONE SECOND YOU HAVE BRAKES THE NEXT IT FEELS LIKE YOU ARE TRYING TO PUSH A BRICK THRU THE FLOOR OF THE VEHICLE TRYING TO GET IT TO STOP. *NM
ONGOING COMPLAINT: BRAKES VIBRATE WHEN STOPPING. DEALER REPORTED FRONT ROTORS WARPED AND PADS HAVE CHUNKS MISSING. DEALER REPLACED WITH PART NOS. 8D0-615-301-M FRONT BRAKE DISCS AND 4B3-698-151 FRONT BRAKE PADS/LININGS. THE CAR WAS RETURNED TO ME WITH THE VIBRATION STILL PRESENT. I CONTACTED THE DEALER SERVICE ADVISOR WHO ADVISED ME TO DRIVE A FEW HUNDRED MILES TO SEE IF THE BRAKES BED AND THE VIBRATION SMOOTHES OUT. *JB
BRAKES CONTINUED TO PULSATE AFTER LAST ATTEMPT TO CORRECT THE PROBLEM. THE DEALER FOUND THAT THE REAR ROTORS WERE OUT OF SPEC AND REPLACED THEM WITH PART NUMBER 8D0-615-601-D.*AK
I PURCHASED MY AUDO S4 AVANT NEW ON NOV. 10, 2001. IT HAS 26,000 MILES ON IT. THERE HAVE BEEN AT LEAST 6 REPAIRS PERFORMED TO CORRECT BRAKE PULSATION OR VIBRATION. PADS AND/OR FRONT AND/OR REAR ROTORS HAVE BEEN REPLACED. THE CAR LEAVES THE DEALERSHIP SERVICE FACILITY OPERATING NORMALLY, BUT WITHIN A FEW THOUSAND MILES THE CONDITION RETURNS. IS THERE A REAL FIX FOR THIS?*AK
PULSATION FELT WHEN BRAKING. DEALER ROAD TESTED AND REPORTED THAT THE PULSATION WAS FELT, THEY INSPECTED AND REPLACED FRONT ROTORS WITH PART NUMBER 8D0-615-301-M. AFTER PICKING UP THE CAR, THE CONDITION STILL EXISTED.*AK
BRAKES PULSATE WHEN STOPPING. DEALER ROAD TESTED VEHICLE TO CONFIRM CONDITION. DEALER REPORTED THAT FRONT AND REAR BRAKE ROTORS HAD EXCESS RADIAL AXIAL RUN-OUT. REPLACED FRONT ROTORS UNDER WARRANTY WITH PART NUMBER 8D0-615-301-M. REPLACED REAR ROTORS WITH PART NUMBER 8D0-615-601-D.*AK
BRAKES PULSATE/VIBRATE WHEN APPLIED. DEALER SERVICE TECHNICIAN FOUND THAT BOTH FRONT ROTORS HAVE EXCESSIVE RUN-OUT. REPLACED BOTH FRONT ROTORS WITH PART NO. 8D0-615-301-K. *AK
CAR SHIMMIES AT HIGHWAY SPEEDS UNDER BRAKING. AUTO GALLERY, 21301 VENTURA BLVD., WOODLAND HILLS, CA 91364 MACHINED THE FRONT ROTORS UNDER WARRANTY AS A TEMPORARY REPAIR SO I COULD DRIVE HOME TO OVERLAND PARK, KS AND HAVE ROTORS INSTALLED. THEY INDICATED THAT THEY GO THROUGH SO MANY FOR S4S, A6S, AND A8S (SAME BRAKES) THAT THEY CANNOT KEEP ENOUGH IN STOCK.*AK
CONSUMER STATED WHILE DRIVING AT 30 MPH AND WHEN DEPRESSING BRAKES THEY VIBRATED/ PULSATED. VEHICLE WAS SERVICED, AND DEALER REPLACED FRONT BRAKE ROTORS AND PADS. *AK
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 26, 2026