Brake pedal on the floor

[jsharpe]

Yesterday my brake pedal literally went to the floor while stopping. Only the very last 1/4 inch seemed to provide any power at all, and I mostly used downshifting and the emergency brake (notice I don't call it the parking brake anymore) to limp home. Then, while turning into the parking space, the pedal had returned to its normal height and all was well. No fluid leaks from the MC or any of the corners, no missing fluid in the resevoir. Over the course of a half hour's tinkering in the parking lot, usually it was fine but a couple times it fell to the floor again.

In any system other than the brakes, I would be inclined to ignore the problem until stuck on the side of the road somewhere. The master cylinder seems the obvious answer, but do they fail intermittently? Any guidance would be much appreciated.

Thanks,
JH Sharpe

[Joe Bob]

Bleed your brakes....replace ALL the fluid, use ATE super blue. If it still happens, the master cylinder is suspect.