Got me, I'm am a sucky mechanic. Yet I have to do it all the time. They both did the same thing, but they were both like that when I received them I guess. One was never used by me until like 4 days ago and the other came on my bike and I've had problems with it since day one. I do ask a lot of retarded questions, but I guess I'm just retarded. On one the leaver was leaky, and on the other one of the pistons were leaky.