I have a 2004 2500HD with about 60,000 miles on it. The brake pads are >5mm and the rotors are in decent shape. When I come to a stop, just before it actually stops rolling, it feels like the brakes let up a little bit. It's literally the last foot or two of rolling, and it's more noticeable under more aggressive braking, though almost always noticeable. It doesn't happen unless I've been up to road speed; it doesn't happen when just slowly repeatedly pulling up a little bit like in a drive-through line. Any ideas what might cause this? It feels like the pedal doesn't really move, but it's like a minor feeling of the brakes going out.