I've got two sets of Shimano M800 Saint brakes.
Set 1 I've had from new and they've been faultless. I've bled them repeatedly, changed the pads, and they've always been great.
Set 2 I bought second hand a while back. They were a bit dodgy to start with, but managed to sort out the front brake by baking the disc and pads and giving them a bleed.
The rear however has been nothing but trouble. Even after baking the pads and discs, there's a significant lack of power on the brake. One finger braking won't lock the wheel (and it's a struggle with two fingers). Leaving the bike for a week then taking it out and the brake has developed an awful squeal, which only goes away after ~30 seconds of dragging the rear brake on down a hill.
Any ideas what on earth is going on here? I'm almost at the point of taking them to my LBS to look at 8O.
