I have a 2011 3500 SRW, I purchased new. Around 25k miles I was driving down the interstate when I hit a pot hole. Instantly I heard a hissing noise, my initial thought was I blew a tire. But as soon as I applied the brake the noise stopped. I let off the brake and it was hissing again. I took it to the dealership and I had a hydraulic line leak behind the pedal. The fixed under warranty and everything was fine. Since then I feel the brakes are getting softer and I hate the way the pedal feels under my foot. When I apply the brake I have a good inch of travel before I hear the "click" in the brake switch, and another inch or so before they grab. To me this annoying and it wasn't like that originally. I have a 2007 2500 and a 2008 5500, neither have this brake issue. It looks to me that there is no adjustment in the brake pedal or on the shaft running to the brake booster. Any ideas or others with this problem?