morris39

Can someone provide the thickness of the backing plate (front & back if different) for the MY 2015 S3 with the optional larger rotors (17") /red calipers? I need this info to determine the thickness of the remaining friction material. I don't have a dedicated tool but will use a vernier gauge with which I can measure the total thickness i.e. friction + backing. I have not had luck by asking after market vendors and am loath to go to the dealer. The measurement needs to be accurate (not nominal) as 1 mm is a significant difference in pad wear. Anyone?

morris39

Info from aftermarket vendor. Total thickness including backing plate F/R: 20/16 mm. Backing plate thickness 5 mm. Sounds right?

findalex

Sounda about right, but to be sure you can just take off your brake pads and check them yourself.

After you take off the wheel, you only need to take off one bolt on the caliper. You can then swing the caliper out and remove the pads. There's gotta be some DIY somewhere on the web. I replaced the front pads on my A3 in about 30 minutes. A little more time for the rear, but it's just as easy as the front ones to remove and exam them.

morris39

Maybe you missed my point. It's about convenience. It has been reported that the brake pad thickness can be measured without even without taking the wheel off and that seems likely to me, assuming the wheel openings are large enough.. Also removal of the rear pads is not so straightforward, the parking brake has to be disabled using a diagnostic tool.
BTW for those who may be interested my quoted dimensions have been confirmed. And ironically the wear limit dimensions provided by Audi include the backing plate. so my question was redundant. I misread the service manual.