2008 KTM 250 xcf-w. So on my last ride i noticed i pretty much lost all rear brakes. I figured the fluid got low and air in the line. I took the rear reservoir cover off and it was full. Next I tried to bleed the brakes and couldn't get any air to come out of the pipe. I then tried to backwards bleed with a large serenge and was unable to pump backwards up into it. I removed the nipple to sere if it had dirt/debrie in it and it was clear. I can pump the brake with the nipple uncsrewed slightly and it pumps air but no fluid through it when the reservoir is all the way toped off. Any ideas on the problem here? Thanks!