https://www.s2forum.com/ For everything related to brake problems, upgrades and servicing. en Fri, 16 Oct 2026 22:49:48 GMT vBulletin 60 https://www.s2forum.com/images/misc/rss.png https://www.s2forum.com/ https://www.s2forum.com/forum/technical/brakes-abs/2162393-dual-stage-vacuum-booster-conversion-kit-availability Wed, 30 Sep 2026 12:53:21 GMT does anyone know if the "Dual Stage Vacuum Booster Conversion Kit" available somewhere currently?


Regards Timo
]]> Timo https://www.s2forum.com/forum/technical/brakes-abs/2162393-dual-stage-vacuum-booster-conversion-kit-availability https://www.s2forum.com/forum/technical/brakes-abs/2162307-just-bought-a-1994-90cs-quattro-sport-and-could-use-some-guidance-for-brakes Fri, 25 Sep 2026 15:05:52 GMT
As the title says, I just recently bought a 1994 90CS Quattro Sport and have some questions about replacing the brakes. The car sat for a few years and so the calipers are completely rusted as shown in the photos. I'm locating in New York, USA, so these cars are pretty rare over here and I'm having a tough time locating any replacement calipers at all. I've read some threads about the B3 or B5 brakes working on my B4, but since this is an S2 forum, I'm not sure if those caliper swaps suggested for an S2 would work for my car. Any information, part numbers or rebuild guides would be appreciated. If rebuilding them is the best option then that's the path I'll take.

I'm truly at the bottom of the mountain and don't know much about these cars other than from what I've researched over the last week or two before I bought the car. I have always been a fan of the classic Audi 90 IMSA GTO and so getting the chance to own the street version of that car was something that I could not pass up. I plan to one day wide body this thing and turn it into a replica of either that IMSA GTO car or the never-raced DTM car.

Also, I'm new to the forum as well so if there is a better place to post a question like this or even a different forum/website all together then please let me know! After some digging, this seemed to be by far the most active community for older Audis similar to mine where everyone speaks English. The seller of the car had suggested joining some Facebook groups but I wasn't able to find many and the active ones I did find were all Germans.

P.S. The Audi barely starts, runs or drives at all and the clutch, brake and gas pedal are all stuck to the floor so literally any guidance at all as to what I should look for/change out/do first would be greatly appreciated. Not just with the brakes. The car has been sitting for a while and needs some love.

Thanks!

Frankie Wheels]]> Frankie Wheels https://www.s2forum.com/forum/technical/brakes-abs/2162307-just-bought-a-1994-90cs-quattro-sport-and-could-use-some-guidance-for-brakes