I was racing last weekend and haven't even looked at my bike since. My last moto I holeshot and landed on top of an uphill triple, just as I had in practice and my other three motos. When I landed and went to get on the brakes for the 180 right afterwards, I had no back brake. My rear brake worked great the corner before then all of a sudden it had no pressure. There was a little fluid on the master cylinder and the swingarm but I didn't really look at it too much. I have Galfer stainless lines and everything else is stock. Do these stainless lines fail? Could I have blown out a seal in the master cylinder from landing on top of a jump? I guess I'm trying to diagnose the lazy mans way.