I rebuilt my rear master cylinder a few months back. And put a new rubber in the resivor I bled almost a whole bottle of break fluid through when Iam at a stand still and push the pedal down the back wheels lock up. But when Iam riding I can literally almost stand on the brake pedal and it goes all the way down and it just slows me down. The back wheels won't lock up at all. Is there something Iam missing? My rear pads have about a little less then 1/8 inch left on them. I know Iam gonna have to change them out soon. But I can't see that would prevent me from stopping. Any help would be apreciated