Am I imagining things? It was night when I got home, but I have noticed my pads are down to approx 1.5mm, I hear what sounds almost like a dull hiss when I grab the front brakes, and when I got home, it "appeared" like I had some black "sludge" floating on top of brake fluid in master brake cylinder. Lil lost...I mean, I know my pads need changing and plan to do next week when Connie goes down for mx, but the floaters? The sound? Is that the sound the pads make when they are about toast? I thought for sure I'd get more than 15,000 miles out of the shoes, but I guess I use them alot. Any input...appreciated...thx