Have you ever seen a new brake rotor come out of the box with rust?

Hi folks. Had my rear brakes done yesterday by the Subaru dealer near me. When I looked at the new rotors (I confirmed with the service advisor new rotors were used, they did not turn the old ones), they were already showing surface rust. See image. Service advisor says that the Subaru OEM rotors “Rust in the box.” What say you? I have had brakes done on a lot of cars and never seen rotors that were rusty the day of install. The center hub section does look new to me. I have had good luck with this dealer in the past.

New rotors usually have coating on them that prevents rust until they’re put into service.

Maybe those got a very light coat.

But from what I see, I don’t think it’s bad enough to get your undies in a rope.



LOL. Thank you, Tester. Do you agree it looks new, but just a bit rusty?

Most rotors I have seen come with a thin coating to keep them from rusting and or in a bag and the coating has to be cleaned off one way or the other… They could have pulled the rotors before and the customer back out or wrong rotors pulled etc etc… then put back on the shelf and they flash rusted…


Thank you, Dave. Do you agree that they look new? That center hub seems to be the clue that they are not used.

Yep, hub looks brand new.

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Yes the rotor hat (center hub) looks new from what I can see…

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Thanks folks. I really appreciate the quick comments. I looked with glasses and a bright light. The rotor edges are definitely new. Also, there is shiny hardware and a bit of brake lube showing. It seems clear I did get a brake job. They do work well.

The rotors look new to me and don’t have any more surface rust than a rotor would have after sitting outside on a rainy day. Looks perfectly normal to me.

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If the tech stopped for lunch after cleaning the anti-rust coating off the rotor and it was a humid day, yep, that’s what it would look like. The brake pads will polish it clean after a few applies. And then it will rust again on the next rainy day.

The best material for brake rotors is grey cast iron… The material most likely to rust if you whisper “water” to it is… grey cast iron!

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Rotors look new to me, but no way to tell just by looking at the photo. If unsure, pretty easy to measure the thickness & compare to spec, using inexpensive Vernier or digital caliper tool. I see that tool using Google available from $2 to $25. Wheel has to be removed of course.

What I’d be more concerned about is whether or not the rotor was thoroughly cleaned before installing it. All of the anti-rust coating material must be removed using soap & warm water, etc. If it wasn’t cleaned, the pads can become contaminated with the coating material and not stop the vehicle as quickly as they should until contamination is eventually worn away. I wouldn’t get myself in a tizzy about this either; it is quite possible the rotor was cleaned using soap and water, and the water didn’t get wiped off soon enough, causing the slight rust on the surface. Maybe take a clean white cotton ball and wipe it on the rotor surface. Do you see anything sticky-looking, or oily, something that looks like a coating material on the cotton?

After stopping a few times reinspect the rotors. If you still see rust spots, they might be pitted. If pitting occurred, then it’s more than just surface rust. By rust spots, I mean like pin points.