I'll keep this short. My '87 4Runner's brake pedal goes to the floor, but when pumped once gives me a good pedal. In the past, I adjusted the e-brake and the pedal came back. In the past it never went so low that I needed to pump it. I have adjusted the e-brakes and still have a low pedal. I'm thinking master cylinder, but hate throwing money at the darn thing.

I think your instincts are correct. Sounds like master to me.


Costas
cars and such...

Sounds like the flux capacitor is running out of juice ... but try the master cylinder first

I was all but certain it was the master cylinder. I already replaced the flux-cap, and the waddle washers, so I didn't think it was those.

Got fluid?

Is the brake booster full of fluid? Sounds like a good chance the master has failed and many times they will fill the booster with brake fluid (not always, but I've seen more than a few).

It never really lost any fluid to speak of. I'm pulling the cylinder now. There was a little rust where the mc met the bottom of the booster, so I assume it was leaking a little around the seal. The booster was rebuilt about 6 years ago.