Did my front brakes tonight and used a long screwdriver to press the piston in, the screwdriver slipped and I bent the inner ring on this part, not sure it is that part, but it looks like the metal one in this picture, like I said, I bent the inner ring of that one, folded a part of the inner circle in on itself:

http://catalog.peachparts.com/ShopByVehicle.epc?q=&yearid=1985@@1985&makeid=63@@Mercedes%2DBenz&modelid=6193%3AED%7C10000135%3AMBC%7C1504@@300D&catid=241658@@Brake&subcatid=241679@@Caliper+Repair+Kit+%2D+Front&applicationid=W0133-1633803@@Caliper Repair Kit - Front&mode=PA
I bent it back as best as I could, but it's not perfect by any means.

I put my brake pads in, they slid in fine, put everything back together, no weird noises when driving, everything stops well.

What is the part that I bent? Is it a big deal? Easy repair?

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1985 300D (CA, 173K)

Dynamite Biodiesel Co-op, Phoenix,AZ