I made a lucky find at the junkyard last week and picked up a set of brake calipers from a 2001 Firehawk... they're not in the best of shape, though, and I'm having one heck of a time trying to clean up the aluminum.

I've tried oven cleaner, Castrol Super Clean, and Mothers cast aluminum wheel cleaner along with an assortment of brushes, but I just can't remove the black speckles from the aluminum. I'm assuming that it's some sort of corrosion.

As you can see in the picture, the bare spots of metal cleaned up really well (better than I ever expected). Any idea on how to remove the black marks? I'd like to leave them bare cast if possible, so no painting (for now); and I really want to avoid bead-blasting the calipers.

 

I'd just paint them with aluminum engine paint. It's what I do with all kinds of cast aluminum parts instead of trying to clean them.

 

That looks like brake dust matter, which probably melted itself right into the aluminum.

I'd paint them too, but make sure you use a paint that can handle the high temps those will see. Engine paint may not be able to handle those temperatures. Do a search and you'll find some info on caliper paint.

 

Been out of the loop for a few days here while I focus on other things, i.e. work. Oh well.

I guess I'll just try the painting route. I found some caliper paint that requires baking; it's supposed to be resistant to chemicals and withstand temperatures up to 900 degF. We'll see how that goes.