89 spirit brake problems

Hi: I have an 89 dodge spirit with 2.5L. I have brake problems that I can not seem to resolve! I put in new pads and when I pressed the brake pedal with the car off, I have a hard pedal. as soon as I start the car the pedal goes to the floor and will not pump up. I have replaced the master cylinder, booster, and bled all the brakes many times. Do not seem to be getting any air when bleeding. I capped the front port on the master cylinder and the pedal remained OK. That led me to believe the problem was in either the left front or the right rear wheel. The rear cylinder seemed like a posibility, so I put in a new one. NO help. The fluid has got to be going someplace! I am not loosing it, so it must be recurculating! Could I have a bad porporting valve? I have tried multiple master cylinders! All ideas appreciated!!!! Denkath

check your metal brake lines make sure that they aren't kinked, bent, or damaged in any other way. When you get a chance, take off your wheels and crack a bleeder screw either at your front caliper or wheel cylinder; if you don't have any fluid coming out, then chances are you have a bad line or lines.