My brake calipers are starting to look pretty gnarly, and I've decided to address the issue. I understand that they're made of aluminum. However, I've seen a few threads addressing "rusty" calipers, which leads me to question the composition of our calipers. So, does anyone out there know for certain, of which series of aluminum our calipers are made?

 

Since when are they aluminum? The stock calipers are not ...thats why they rust

 

Mine dont appear to be painted, and they look flakey-white in places (that they aren't PNWmouldy green) Between that, and seeing a few people polish them, I suppose I made an incorrect @$$umption. Either way, I have use to know the composition. Anyone?

 

I think they are a cast iron or cast steel composition. Not sure on the what the alloy actually is but it is ferrous based

 

I suppose I could assume the worst and prepare & paint them as if they are High-Carbon Steel. Such a pain... I was hoping I could get away with just cleaning them up and allowing a controlled protective corrosive layer to develope... I suppose that idea is out the window. Thanks for the info, Danno!

 

The newer calipers are plated with an anti-corrosive coating I think....but I'm afraid you are stuck cleaning them up and painting them.....

 

mine look pretty gnarly too

https://www.rx8club.com/series-i-do-yourself-forum-73/diy-racingbrake-4-pot-caliper-2-pc-rotor-front-brake-kit-191292/