After car on jackstands, brakes are mushy.

My guess would be a failing master cylinder. If pumping up gets things sort of working then that is probably the problem.

Jack stands is probably a coincidence.

John

I test drove it at lunch and here's what I found. If while driving I fully depress the pedal, it will not begin to engage the brakes until I am about 2/3 down. Pumping the brakes has no effect, the brakes do not engage until around 2/3 depressed.

However, if I hold the pedal down about 2/3 and begin pumping the pedal only the bottom 1/3 over and over, it grabs and grabs. So, as long as I keep the pedal 2/3 depressed, I can repeatedly engage the brakes, it's that first 2/3rds that do nothing and the bottom 1/3 doing all the work.

Is that still a master cylinder, booster or air?

Exact same thing happened to me on my 1986 Toyota truck. Here's what it was; The brake master cylinder 'O' rings had desintegrated, and fluid started leaking into the brake booster, corroding the diagphram. The back of the master cylinder is conveniently aimed so if it leaks it goes right into the booster. I got a used booster and a rebuilt master cylinder and it went back to normal, although I bled the crap out of the brake system after that in case of contamination, and rebuilt the rear wheel cylinders.

This is hard to see because the fluid goes into the brake booster, not onto the ground. Brake fluid is corrosive, so it doesn't take much to kill the internals of the booster. I didn't even notice that much of a drop in fluid, I just thought it was the wheel cylinders leaking a little, which I wasn't too worried about.

Hav> I test drove it at lunch and here's what I found. If while driving I

Check you local auto parts stores as well. Sometimes with rebuildable items it is easier and about the same cost to buy locally.

John