Own a 2015 forester with 150 km. Replaced rear brake rotors/pads at 90k. At 120km rear caliper seized and resulted in having to replace rear rotors/pads and calipers. Now at 150km one of the year old calipers seized when on a long road trip so now replacing rear rotors/pads and calipers. Never had to do any work on front. Any ideas what might cause this besides faulty calipers?