98.5quattroA4

I am doing a research project involving some braking calculations for the B5 S4 and I can't seem to find the diameter of the pistons in the front caliper. If you guys have one laying around that you could measure, know it off the top of your head, or feel like taking your wheel and brakes off to get the measurements for me I would be greatly appreciative!!!

I waited until the last minute and of course need this information as soon as possible.

Thanks in advance, folks!

donromani

I've been hoping someone else could help you out but so far no luck. I have no idea, but it has to be around 2.5 - 3 inches. Can't do better than that at the moment.

98.5quattroA4

thanks for the help, hopefully someone has the info!! I googled all over the interwebs with no luck.

98.5quattroA4

anyone?

98.5quattroA4

In case anyone was wondering, or searches for this later, each of the pistons is 38mm in diameter.

complacentsee

Glad you found it. I remembered seeing it listed with some rebuild kits. But then I couldn't find any rebuild kits and thought maybe I just saw it on the rears.

donromani

1.5 inches, I was way off. As usual...