I have an 2001 a6 quattro 2.8. One day I got in the car and the brake pedal went to the floor. Ipumped it a few times and it got stiffer and then over the next 10 miles it got stiffer and stiffer and then the front right caliper stuck. I pulled over, took off the wheel and let out pressure and used the e brake to drive home. The caliper was fried. So I replaced the caliper, ended up replacing rotors, and pads while I was in there. I had all calipers off the car so most fluid was drained from them. Now I put it all back together and I dont have any pedal. Goes right to the floor. Tried bleeding and I am not getting any fluid to any of the calipers. The pedal will not get any stiffer. I have a vacum to do a one man bleed job too which I also tried. I hooked it up to the line to see if something was clogged. The one line I got about 2-3oz of fluid but the reserviour didnt really go down much. Everything seems tight and no leaks anywhere as the vacume will hold pressure when connected to each line. Is this a problem with the master cylinder? No pedal pressure at all....