My rear brake seems to have failed on me today. Near the latter part of my ride (which was quite excellent, and one of the last, I think, out here on the Front Range), I noticed the lever getting closer to the bar each time I used them. It seemed to even out though and not get any worse, so I finished my ride without checking it. Get home, take the bike off the rack, and the lever goes all the way to the bar without any pressure. I can't seem to figure out the problem. The lever adjust screw is still there and screwed in pretty far. I can't find any sign of fluid leak (checked where cable was tied down, check MC, checked caliper, pads, and rotor.) So I figure that there must be a seal issue or internal leak somewhere. I've heard of the lines bleeding internally- is this possible? And how would I tell? These brakes are about 3-4 years old, have been bled, and were very tight and responsive prior to riding. Thanks guys!