Try stomping on the pedal.

I just replaced my brake master cylinder.  If I pressed the pedal gently, I could push it to the floor.  If I stomped on it, I could stop.

I suspect the seal around the piston would "parachute" out a little with a faster pedal application.

Just a guess, but the new master cylinder fixed mine.

Dan Brideau

Original Message -----------------------
Need some help !

Drove my 80 yesterday and every thing was fine. Try her this morning and
don't have a brake anymore. Seems like air in the line. When I pump I have
some function but the pedal goes slow down. Checked the break fluid, to the
upper line, checked for puddles, none. Anybody with some explanations?

KARL