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Rotor rust?

4K views 12 replies 6 participants last post by  CoppeR 
#1 ·
So I bought a gently used 2012 earlier this week, and noticed that the front brakes (first pic below) seem to have a black plastic cover over the base of the brake rotor - right where it meets the rim/lugs. It's screwed down by several screws around the diameter.

The rears (second pic below) don't have this plastic cover, and you can see the exposed part of the rotor (not the braking surface) has some surface rust from being exposed. Is my V just missing the black plastic cover in the rear, or is this normal?

Alloy wheel Tire Wheel Rim Automotive tire


Alloy wheel Tire Wheel Automotive tire Rim
 
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#3 ·
the 'black cover' is anodized aluminum. Instead of an iron center (like in the rear) aluminum is used for the non-contact surface area of the rotor to reduce mass.

Since our rotors are not zinc coated, rust is normal.

Fortunately, the rears are a common part. You can even pickup a set of coated rear rotors from napa. As for the front not rusting, honestly it would surprise me if they 2 piece brembo's were coated.
 
#4 ·
M5eater said:
the 'black cover' is anodized aluminum. Instead of an iron center (like in the rear) aluminum is used for the non-contact surface area of the rotor to reduce mass.

Since our rotors are not zinc coated, rust is normal.

Fortunately, the rears are a common part. You can even pickup a set of coated rear rotors from napa. As for the front not rusting, honestly it would surprise me if they 2 piece brembo's were coated.
That's a far better explanation!!!
 
#12 ·
No, I had some blue 3M painters tape laying around, so I used it. It doesn't leave any residue. I masked the rotor face, as well as the hat where it meets the wheel. I got a tiny bit of paint on the rotor face where my masking wasn't perfect, but it came right off first time I put on the brakes... ;0)

I took the cell phone pic specifically for this thread, my wheels are pretty dirty right now. A little more elbow grease with some soap and water, and they clean up really nice...
 
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