[jdmccright]

I'll comment on the backing/shim plate on some brake pads because it is here that I have seen some reason for poor piston/bore alignment resulting in sticking calipers.

Some backing shims have a paint or rubber coated surface to help reduce squealing. The problem with this is that the brake piston doesn't contact the whole pad backing surface, only that narrow circular area of the cup edge. Eventually, the coating wears away and does so unevenly, causing the pad to become out-of-true with respect to the piston. The pad starts to wear unevenly, causes the piston to become cocked in the bore, and eventually leads to overheating of the rotor and warpage.

Simiar to this are shims made of cheaper steel rather than stainless steel...as well as unshimmed pads on steel backing. As the plain steel rusts, it grows and expands unevenly causing it to become crooked. I've seen this condition exaggerated on trucks that see alot of salt and water.

Because of this, I only buy pads that have an uncoated, stainless steel backing shim. I apply an anti-squeal compound (not silicone) and assemble it before it is dry. Hope this helps!