I purchased a brand new master cylinder to replace an old surface rusted unit that I can't get to stop leaking. I don't mind the looks of the raw cast iron, but I know it will rust in due time. I thought about coating it in the cast iron finish spray paint before installation, but wonder if it will peel off if I get any drips of brake fluid on it. If you have done this, did the finish last? I know powdercoating would be better, but I'm on a time crunch and need to install by the weekend.