OK so my 03 WR450 has been sitting for 3 months this weekend with temperatures in the 50's all week there should be just enough snow melted in a couple of areas for some riding. I did not check anything out first just took my 450 out to the riding area. It fired up easily enough and I take off. Only to find out I have no rear brakes. Back to the truck I try bleeding the rear caliper first just brake fluid then I get some air bubbles in the brake fluid. I keep bleeding until the fluid is down half way in the window still no brakes and no brake fluid on the truck. Well after 3 months of no riding I figure if I can get going with only one wheel being powered. I should be able to stop with just wheel also. So any thoughts on how to get the brakes working again? Should I just fill the reservoir and keep bleeding? There was no leakage anywhere. Does the Yamaha have a history of the master cylinder going out?