I have a 00 A6 4.2. There is a severe problem with the brakes, two wheels locked up and the brake pedal is so hard its unpushable. I havent really heard of anything like this. Any ideas .. Thanks , also a few days earlier i was going to change the pads but the caliper wouldnt open enough.

 

Hi Dale,

To me that sounds like a seized caliper. My 03 3.0 just had it's stock front calipers seize, so that's not out of the realm of possibility. Brake lockups can also happen due to a collapsed break hose. The easiest thing would be to just bring it to Midas and have them do their free diagnoses and just have them put it back together with the broken parts for free.

 

you might try cracking open the bleeder valve on the caliper and see if with it cracked you can retract the caliper, it may be a problem with you master cylinder if it is not allowing the pressure to release properly. In other braking systems when I have seen this happen it was due to clogged passage in the master cylinder or no freeplay in the pedal linkage to the master cylinder. If you care has antilock brakes it could be something to do with that also. Also make sure the pads are the correct ones, sometimes different years/brake options have different thickness of pads. Good luck. If it had been only happening on one side I would have suggested you check the flex hose on that caliper, as a failing flex hose can act as a one way check valve and lock one wheel.