I replaced the front brakes pads on my '86 300E maybe 5 or 8K miles ago with (I believe) Pagid semi-metallics. They worked, and still do work fine, but they've lately started making a very disconcerting "graunching" noise during the last 10-15 ft or so of stopping, especially when they're cold. It sounds like a sort of muted metal-on-metal sound, as if the pads were worn down to the backing plates. I pulled the pads a couple of weeks ago to check them, and there's plenty of material left on them. The pad compound appears to have quite a bit of metal in it, though. This noise didn't appear until the last 2K miles or so.

I've also noticed that the rotors seem to have considerably more wear on them than I would have expected. The surface is fairly smooth, without any noticeable galling, but there's a deep wear ridge now.

Is this typical for these pads? I've run semi-metallics before in other cars and haven't had this problem. In the near futue I plan to replace them with Porterfield R4-S pad and new rotors, but in the meantime I'd like to find out what's going on with these.

Thanks,

Gary