Rust!

[Zwerius]

After owning the car for 1.5 months now, I saw marks of rust on the left rearwheel.
See picture.


According to the dealer this is normal, since the wheel hubs are made of carbonsteel.

However I never saw this on one of my previous cars (that also had wheel hubs of carbon steel)....

What do you guys think?

 

[Gonville]

Looks like it is coming out from beneath the logo cap rather than the bolts. I think that the brake hub usually goes rusty and can be seen behind the alloys. Maybe it's running through behind the wheel into the hub. Take the cap off see what you can see?

 

[XXL]

Hoe is dit uiteindelijk afgelopen mbt die roest ?

 

[Zwerius]

No news yet.

I plan to remove the rear wheel myself.
Just to take a closer look.

 

[Zwerius]

I removed the rearwheel to taker a closer look.
This was what I saw:


Maybe nothing to worry about, but it doesn't look nice either.

The disk (brake) is a bit rusty because I didn't use the car for two weeks (holiday)

 

[Gonville]

I guess the discs would look like that if unused maybe if you use regen a lot it will stay nicely unused. ;-).

That inner hub looks roughly the same as every other car I have owned. Maybe just put some silicon gel around the cap to keep water out? I guess it's running down between the hub and the wheel so you wouldn't want to block it off really.

 

[jackt]

Its pretty normal for inner hub to go like that its not actually "rust" in the truest sense as its not detrimental to the integrity of the metal, it becomes a protective layer.

At least that what I was told when I pointed it out to the dealer on my current car.

 

[MikeS]

Yep - looks just like a typical BMW hub - my Z4 was the same. Still disappointing as other cars I have owned didn’t look like this.

 

[Dutchi3]

The same here only back right wheel has rust marks on it like on the picture. I have no idea how to prevent it.

 

[jadnashuanh]

Iron rust, anyways, ends up being a larger compound than elemental iron, so as a result, it exposes more unoxidized steel beneath it, which then can rust (oxidize). OTOH, aluminum rust is almost exactly the same size as elemental AL, and provides a great, thin, strong, stable layer on the surface, preventing the rest from 'rusting' away rapidly. On AL, if that wasn't the case, since AL is so reactive, there'd be nothing but its oxide around, and is the main reason why it takes so much energy to extract AL from its ore - it really 'craves' oxygen. Look up a thermite reaction, and you'll get a graphic example of how aggressive AL is verses iron.

 

[bxb40]

Treat that small area with antirust to passivate the metal, then paint few coats of brake caliper paint with a small brush. Will last a long time... Can paint hubs too for extra protection.

 

[Dutchi3]

Great, thanks for the tips