This one for my 80. Most of the time they work great, nice light pedal with good stopping. But if I have to jump on them hard it feels as if I lose all the power from the booster!!! They still work good, but the pedal is hard to push (atleast harder than it should be) and I can feel resistance from the pedal, like something is pushing back on the pedal. Oh, it actually makes a popping sound and the pedal moves (closer to the floor) when it happens. From what I can tell all the brake stuff is original from 1980, i.e. the booster and M.C. I have had to replace one of the wheel cylinders but it was doing it before that. I'm thinking the booster is bad. Ideas?
