I had to change my front tire and now when I put the wheel back on, as soon as I tighten the pinhead skewer, a metallic scraping sound starts coming from the disc brake.
I'm pretty sure it's not the disc rubbing on the brake pads, but rather the "arms" of the disc are rubbing on the "housing" below the pads. (Sorry I don't have better terminology). I'm starting to see shiny metal on the housing where the coating of dirt is getting scraped off. These are Shimano M495 disc brakes.
I've tried seating the wheel/axle ever so slightly differently in every direction, and each time, the wheel spins free until I tighten the skewer, at which point the scraping starts again. Any tips or tricks?
You may just need to reseat your wheel. Or my may need to readjust the position of the caliper. Maybe when the bike was built, the wheel wasnt seated right, and the caliper was adjusted to the faulty position of the wheel.
Thanks for the tips - I'm not confident enough to touch my disc brakes so I took it to my LBS. The mechanic adjusted the calipers - loosened the skewer, loosened the calipers, held the brakes then tightened everything. Sounds like what rydabent said.