snapdragon

Maybe the piston is seized? One of mine was, but was moveable manually.
Needed a new seal and dust cover and cleaning up with 2500 wet & dry in the sink.

mishar

Are you sure that both sides are working? One may be seized or have a loose contact. Do you have problem with retracting pistons on both sides, or may be just on that seized side?

2005 won't retract electrically. After VCDS retracting I have to push them in using C-clamp.

snatchman

I watched both sides during the retracting process. I could here both motors but neither piston moved. I tried pushing them in with a C-clamp but neither budge.

mishar

For how long that retraction lasts?

snatchman

About 15 to 20 sceonds.

mishar

That should be enough. You may unscrew motors, check if everything is OK there and try retracting brakes by manually turning it.

snatchman

Any instructions on how this should be done would be greatly appreaciated.

snatchman

Thanks all for your help. I completed my first rear brake job on my 06 A8l. During my second attempt the passenger piston went in fairly easy with a C-clamp, the driver side was a little bit more difficult. I had to apply pressure with the C-clamp and turn the caliper slightly with channel locks, then the piston retracted with just the C-clamp.

The Ross Tech tool has officially paid for itself.