Brakes the leak brake fluid?

for $60, get a new master cylinder, unless you want to mess around with a worn out master cylinder that might not take a rebuild.

If you're in a brake class, your text book should have info on how to bench bleed a master cylinder. If you do not know how, get a Haynes or Chilton's book, they give a good description on how to do it.

that would take place while an air bubble interior the brake lines lines up completely once you step on the brake. Or if the brake fluid is low. i could verify the fluid point and bleed the brakes first. Thats a $10 fix. You dont say how previous the vehicle is or how many miles on the vehicle. The cylinder on a particular wheel could basically provide up that particular wheel. regardless of if it have been leaking, the different 3 wheels could have tension to provide up the vehicle. The pedal going all a thank you to the floor shows loss of tension interior the full equipment. Get a 2nd opinion. If it ever happens to you back, pump the brakes straight away to tension fluid rotation. Pull over and verify your brake fluid.

go to autozone or any other auto parts store and get your self a new master cylinder and install it (ask them how to) or have it installed i prefer doing my own work though

hope this helps

Put a new one in, I just don't like rebuilding anything that has to do with brakes.