I did a complete flush when I did the calipers, as well as can be done with the ABS crap. Its not the pins this time, if anything the ear bores are oversize since the caliper moves up and down quite a bit when the rotor is rotated back and forth. (I have pulled the caliper to confirm it is the pistons) Stock calipers went 9 years 121K, reman junk bad less than 4 years and 26K. I knew better and should have purchased new like I've done in the past with other vehicles. I'd like to get new calipers with metal pistons and silicone seals instead of the phenolic pistons and EPDM seals that all the rebuilt ones seem to have.
So far the only other new calipers I've seen are from Stainless Steel Brakes and they are huge $$$, plus they didn't look like they had outer dust boots on the pistons.