The rear brake is completely out on my 2000 325 trailboss. When you step on the pedal, there is no pressure or resistence there. Everything seems intact, checked the little reservoir down by the peddle and it is full and has clean fluid in it. the pad in the rear has some meat on it, no leaks anywhere.... I am pretty lost here. Is there any kind of steps I can go through to try and troubleshoot or diagnose the problem? this is all new to me. Thanks in advance.