I think I made a very bad mistake. I pulled and cleaned the calipers (did not split them) but when I removed the dust boots from the pistons I did not keep the metal bands that held them in place. I assumed that the rebuild kit would contain these. They were rusted. The rebuild kit is all rubber- no new retainers. I assuem I will need to replace these or are these spring clips rings not needed on the replacements? Followup question. If I need them were cani get them?