I removed my caliper last week, it was 19mm which is an odd size. On a 2006 Sebring, 2 large colts on the back.
I also noticed on of brake pads on one wheel were worn more than the other, and could not easily get a caliper over haul kit in Canada, so I pulled out the caliper pistons and cleaned them and put back and now ok. I strongly advise not just bleeding calipers but over hauling them if suspect. Replacement calipers cost a fortune in Canada.