[caddyman379]

1995 Buick LeSabre 3.8 93,000 miles
Has _ABS_

Hi all. I'm helping my friends with her buick. I've test driven and at different times the pedal goes to the floor with ease, with only the drum's being used. (This was verified with vehicle in drive on jackstands) Sometimes the pedal operates normally, as in firm and all four wheels stopping correctly. During the times it goes to the floor, the drums engage very sharply.

There's plently of brake fluid and I see no leaks. Power booster seems to be operating correctly, and there is vacuum to it.

Given all these symptoms, I picked up a master cylinder to replace this one. Anyone have an ideas on what else this could be? No Brake or ABS lights illuminate. Pads and rotors look fine.

Thank you in advance.