I just took my 1 month old WR450F for the 4th time out on a ride with my friends. Meanwhile riding I noticed that my front brake lever started losing that free tolerance of a few milimeters and that the brake pads started dragging on the disc. It seemed as it was pumping up. I stopped and bled the front caliper which helped to solve the problem (the free tolerance returned immediately) however after a few minutes the problem returned. The brake itself worked very well, there was no sign of air in the hose, nor did I over brake or caused the front brake to overheat, just normal enduro riding. I repeated the bleeding steps a couple of times , 4 or 5 or so, until my brake cylinder became empty, without being able to solve this nasty problem. What is causing this problem?:? The brake lever is not pushing the cylinder, I already checked that. Its actually a AVS lever that can return all the other way around. I am wondering whether the oil fluid perphas was no good. I had it changed just before the problem occurred, but done in a very professional shop. Anyone that has an idea what happened?