brake pedal to floor on 1990 Volkswagen Jetta

my brake pedal goes to floor, but will pump up after several hits on pedal. have bled brakes, checked wheel cyl for leaks. Also idles perfectly until I try to accelerate from stop. once moving fine. Am thinking vacuum somewhere?

Asked by for the 1990 Volkswagen Jetta
1 answer
Does the pedal go to the floor if the engine is off? If so the master cylinder would be my first suspect. The problem is likely to be the master cylinder. Was the brake fluid black and contaminated prior to bleeding the brakes? If it were a brake booster issue the pedal would become hard and require more pedal effort to stop the car. If the servo leaked or check valve was bad the engine would idle rough due to the vacuum leak.