Air in the system would make the pedal "spongey". What you are describing (having to pump the pedal for pressure) sounds more like an internal leak in the master cylinder. The seals are probably begining to wear out. If you want you can try to bleed the system to be positive it's not air, but I think you may find it's the master cylinder (that is if it's not leaking anywhere else and that there is absolutley no fluid loss). Steve --- In dmcnews@xxxx, Felix S <melvnhel@xxxx> wrote: > Hello List, > > Another problem which is kind of scary, I seem to be losing brake > pressure when I am at a stop light or pulling out of my driveway. Pressure > I mean the car is stopped then I feel the pedal move, all the way down to > the floor, I pump it and the pressure is back. I would think Master > cylinder etc. but here is the funny part. It happens only sometimes > (haven't seen a pattern yet), the day could be super hot or cold doesn't > matter, there is no leaking brake fluid anywhere, the fluid is always full. > Someone once told me that I had air in my system, maybe but that's kind of > weird. Or an internally bleeding brake master cylinder, so I can't see the > leak? I first noticed this during a parade and we were going stop and go up > a steep incline for a while and then stop and go all the way down, and > that's when I noticed it. Anyone had a similar incident before? > Suggestions? > > Thanks in advance > > Felix