brake problem

[frankzlt1]

Ok he's a question, when I put my car away for the winter the breaks were acting up. When I step on the breaks I would have very low pedal, I thought I had broken line when I checked there are no broken liners, if I pump the pedal I have a good pedal and it doesn't go down with pressure on the pedal. But when I release the pedal and then step on the pedal again I lost the good pedal and its low again, I've chacked the vacuum to the booster and its got it. And the master cylinder is full of fluid. I didn't spend to much time on it because I was putting it away for the winter anyways. I was just wondering if anybody had some ideas what to look for when I uncover in spring.