I experienced a brake caliper failure this past week. RF Caliper was seizing and binding the brake causing a right pull and shuddering through brake pedal.
Today I removed and replaced RF caliper w/ a Napa rebuilt part ($60). I noticed the dust boot for the piston had a damaged section. I used air pressure to eject the piston and found corrosion on the piston, caliper, and caliper seal (rust particles).
I failed to inspect the dust boots on the calipers when I replaced the brake pads in late 2015.
Piston was pitted and plated w/ rust corrosion. This occurred in S Texas w/ no salt on the roads.
Lesson learned is to carefully inspect the caliper piston dust boots when replacing brake pads.

Good Luck

 

thanks OP for the update!