The adjustment screw on my rear caliper seems to be seized. I was changing pads and retracted the piston without a problem, but when i went to tighten it, it turned a few turns than stopped. The wheel steel spins freely, but I can't turn the screw anymore. Would rebuilding the caliper solve this problem?

 

Would be worth taking it apart to see if any real damage is done. If you didn't force anything, lube and cleaning should fix it.