Q: what could be wrong if I have spongy pedal and i have replaced master cylinder and bleed brakes multiple times?

There are several factors that can lead to a spongy brake pedal. When there is fluid loss, it could be caused by a faulty caliper, bad wheel cylinder, leaking master cylinder, or even a ruptured line. Things can get a little more annoying when there is no fluid loss. When there is no fluid loss on older vehicles that have a spongy brake pedal, the first thing I like to look for is a rubber brake hose that is showing signs of failure. As the brake hoses age, they don’t always just rupture and lose fluid. A lot of times they will give warning signs, like bulging when the brake pedal is pressed. When you hit the pedal, they will actually swell up like a balloon because the hose has actually failed internally. It is possible that there could be a problem with a master cylinder, or even an anti-lock brake controller, but the hoses are where I would begin my search. If this is something that you feel you could use a hand identifying, consult a certified mechanic, like those available at YourMechanic.com.