He's got a valid point here. It sounds like a master cylinder problem. Just because you replaced it that doesn't necessarily mean that the new one doesn't have a problem. My neighbor went through 3 master cylinders in one day on his Tahoe before he got one that was good. If you're unsure, a good garage should be able to test it and verify that it's good. > > > Did you use parts from a D vendor? > > Andy > >