Ok, seriously, get the wheel off, remove the caliper. Then check your pads, my pads separated from the fixed backing. I am dead serious here, it caused my wheel to lock up from friction heating the brake fluid so hot it expanded the lines and made it lock the caliper.So my rear brake just stopped working. It wont even hold the bike in place in my drive way. I do not use it all that often but I am still curious why it might have just stopped working.