We have rust forming on our 2008 135i wheel hubs, visible through the rim openings. Looks abnormal for the year and mileage (9k). Any ideas how to correct and prevent short of removal, sandblasting, priming and painting?
I had the same problem on my 01 330Ci and it will involving a bit of painting. I ended up cleaning it really good with wire brush, blew it off with a air hose, and painted it with gray VHT Hi temperature paint. Was still looking good after quite a few years. I had the car on a lift and let the wheel spin with car running and in gear. Any overspray that hit the rotors cleaned itself off the first time I hit the brakes. Wasn't a major undertaking at all.
I believe you are seeing part of the rotor, the rotor is made of iron and rusts. This is normal. All you can do is sand and paint if you like, but it is not needed. It is so thick it will basically never rust through.
No, I know the difference between hubs and rotors having done a few brake jobs over the years. This is the first time I've seen hubs rust, the fronts are fine.
The rotor "hats" rusts quickly. BMW supplies (or used to) the gray painted hats to keep the rust off. You can duplicate this look as mentioned above.
But the rotor completely hides the hub from view. So you are seeing part of the rotor, I am not talking about the wear surface.
