1993 Ford Thunderbird • 6 cylinder 2WD Automatic •

I have a 1993 Ford Thunderbird LX 3.8L. The problem I am having is with the brakes. When the car is off, The pedal travels normally and has excellent brake pressure. When the car is running, the brake pedal goes to the floor and barely have any pressure. I have replaced the rotors and brakes, bled the lines at the calipers and master cylinder, checked for fluid and vacuum leaks (none). There is plenty of suction at the hose going to the brake booster. I was thinking that my brake booster itself is bad and was wanting another opinion. I have never had a brake booster go out on any vehicle I have had before so am unsure myself. Thanks for any and all advice on the matter.
June 4, 2011.

Check the brake master cylinder could be leaking internally-

Jun 4, 2011.