chris777

So have a 91 Audi 200 all the rubber hoses to calipers were replaced last year along with the master cylinder. After awhile i had a very weak pedal and then no pedal at all. Used pressure bleeder twice now!
Things i think it might be...
1. Rear regulator proportioning valve... but wouldn't that just cause no rear brakes?
2. Part of accumulator /bomb check or pressure relief valve.
3. Master cylinder again?
Any help?

Wisconsinguy

I'm not sure if older audis are similar to older vw's but I had one that the rear calipers would not adjust the parking brake. There was a large gap between the Roter and pad, there was just not enough pedal travel to move the pads far enough to contact the roters. I tried to bleed them for 3 days once I replaced rear calipers and adjusted parking brake all was good. This had the calipers that ratchet out when you set the parking brake and have to manually rewind when replacing pads. Not sure this applies to your Audi but took me a few days to figure out.