[TheMidnightNarwhal]

I received some rotors as I'm about to do my front brakes. As you can see from the pictures, one rotor has this weird looking rust or wear? I've never ever received rotors that looked like this. You can see how the other rotor I received is normal.

Is this common or is this normal? Or maybe the protective coating wasn't done properly?

[M3SQRD]

New brake rotors are often covered with an anti-rusting “oil” to prevent the iron in the rotor from rusting before use. It appears it either wasn’t uniformly applied or it’s worn away with time. You should use something like Brakleen (brake clean spray) before using the rotors. I find it extremely odd that the rotors were all delivered in one box without each rotor being in its own box. Where did you order these from?

[TheMidnightNarwhal]

Originally Posted by M3SQRD

New brake rotors are often covered with an anti-rusting “oil” to prevent the iron in the rotor from rusting before use. It appears it either wasn’t uniformly applied or it’s worn away with time. You should use something like Brakleen (brake clean spray) before using the rotors. I find it extremely odd that the rotors were all delivered in one box without each rotor being in its own box. Where did you order these from?

I didn't think coated rotors were oil filmed. But yeah I did try brake clean and it did not wipe away. Seems like it's part of the coating or the material?

Oh just to clarify, 2 of these pictures are the same rotor and the third one is one of the rotor that are good. They both came in their own boxes.

[M3SQRD]

Originally Posted by TheMidnightNarwhal

I didn't think coated rotors were oil filmed. But yeah I did try brake clean and it did not wipe away. Seems like it's part of the coating or the material?

Oh just to clarify, 2 of these pictures are the same rotor and the third one is one of the rotor that are good. They both came in their own boxes.

What do you mean by “coated rotors”? Some rotors are coated but not all. Do you have a link to where the rotors were purchased? Rotor manufacturer /brand? Perhaps the product description will shed some light on what’s going on.

So these pictures were taken after trying a brake cleaning spray?

If the holes were drilled in after the rotor was cast, it’s possible it’s from the drilling process with a cooling fluid being used. It seems like it all starts with the holes.

[TheMidnightNarwhal]

I took a second look at the hub/hat sides and it's not as bad as I thought so I guess I'll just install these as is. Won't be seen to much through the wheel.

[TheMidnightNarwhal]

Originally Posted by M3SQRD

What do you mean by “coated rotors”? Some rotors are coated but not all. Do you have a link to where the rotors were purchased? Rotor manufacturer /brand? Perhaps the product description will shed some light on what’s going on.

So these pictures were taken after trying a brake cleaning spray?

Coated I mean not bare metal, in this case they are zinc coated/plated entirely. They are R1 Concepts E line rotors.

I took the pictures before trying the brake clean but after trying it, they look the exact same.

[Redd]

These are definitely brand new. Used or even skimmed rotors don't have surface patterns like that.

[M3SQRD]

Originally Posted by Redd

These are definitely brand new. Used or even skimmed rotors don't have surface patterns like that.

Correct. I believe we’re all in agreement they are new. The question is what’s causing the surface staining - “oil”, incomplete/improper surface coating/treatment, etc? Will the surface staining wear off if installed with new pads or will you get an incomplete/inconsistent pad transfer layer? Would a cold race pad compound machine off the surface layer or …

[M3SQRD]

Originally Posted by TheMidnightNarwhal

Coated I mean not bare metal, in this case they are zinc coated/plated entirely. They are R1 Concepts E line rotors.

I took the pictures before trying the brake clean but after trying it, they look the exact same.

That’s what I thought you meant but wanted to make sure it was. Have you searched for reviews on the R1 Concept E rotors having a similar surface issue or any issue actually? Biggest concern would be if this staining prevents pad transfer or inconsistent pad transfer. Best case is it wears off easily during the pad bedding-in process.

What pads are you using with these rotors?

[Redd]

Looks like a slightly worn off or unevenly applied oil coating. I wouldn't worry about it and just use as is. If it worries you give it a spray of brake cleaner.

[M3SQRD]

Originally Posted by Redd

Looks like a slightly worn off or unevenly applied oil coating. I wouldn't worry about it and just use as is. If it worries you give it a spray of brake cleaner.

He says he applied brake clean and no change. I just did a search and found quite a few complaints about their e line rotors. Geomet apparently are far superior. One thing I noticed with the e line is the rotor pad radial depth is longer than the actual pad radial depth which leaves what appears to be an unswept area of the rotor. For the e line this starts to rust immediately and continues to rust because the pad is not deep enough to reach the rotor IR. Geomet rotors have a double step from the mounting hat to the rotor surface and, therefore, the pad and rotor radial depths are the same so no rusty unswept area around the rotor IR.

[TheMidnightNarwhal]

Originally Posted by M3SQRD

He says he applied brake clean and no change. I just did a search and found quite a few complaints about their e line rotors. Geomet apparently are far superior. One thing I noticed with the e line is the rotor pad radial depth is longer than the actual pad radial depth which leaves what appears to be an unswept area of the rotor. For the e line this starts to rust immediately and continues to rust because the pad is not deep enough to reach the rotor IR. Geomet rotors have a double step from the mounting hat to the rotor surface and, therefore, the pad and rotor radial depths are the same so no rusty unswept area around the rotor IR.

Ah well to late now, did the rears before winter already. The conclusions of my searches were that they were a pretty good bang for buck aftermarket choice. I'm not rich enough to chase perfection . Andddd Rockauto didn't carry those either so didn't even have the option although I did look at them back then.

But about the rusting, the whole rotor is coated, so the unswept portion just stays coated. Granted I know the zinc coating will most likely not last the life of the rotor but like for now and a salty Canadian winter, the rears still look fine.

[M3SQRD]

Originally Posted by TheMidnightNarwhal

Ah well to late now, did the rears before winter already. The conclusions of my searches were that they were a pretty good bang for buck aftermarket choice. I'm not rich enough to chase perfection . Andddd Rockauto didn't carry those either so didn't even have the option although I did look at them back then.

But about the rusting, the whole rotor is coated, so the unswept portion just stays coated. Granted I know the zinc coating will most likely not last the life of the rotor but like for now and a salty Canadian winter, the rears still look fine.

Maybe the front rotor will have the same radial depth as the pad.

The rust was forming on a brand new e line zinc coated rotor. R1 Concepts solution was to spray paint the part of the unswept rotor black with high-temp caliper paint. That’s a company that stands behind their product

[MADBMWX5MC]

So have you completed the install on all 4? How did it all come out?

[TheMidnightNarwhal]

Originally Posted by MADBMWX5MC

So have you completed the install on all 4? How did it all come out?

No not yet, I ended up returning this one for another after seeing how easy and straightforward Rockauto's replacement process is. And they provide a free return label. Like Amazon level of customer service. They shipped me my replacement item when my return package was picked up.

I also discovered kind of like a crack/line on the face of the rotor around the hub, hard to see in the pic but figured I wouldn't take chances with a potentially failed coating either. The other rotor does not have that line and if I recall correctly, none of the rear rotors had that line/mark either.

[MADBMWX5MC]

Crack/line is never good news, unless you are a junkie (pun intended), but not on a rotor. Thx for the update.

[335i54n]

new old stock, the rotors have been sitting for a while, and the wet coating has dried/stained. Always check rotors/heavy items shipped because they are more likely to have been dropped several times.

[TheMidnightNarwhal]

Well interesting update, I received my free replacement from Rockauto and it was still stained a bit but meh whatever it was okay enough to the point I was going to install. I just wanted to confirm with R1 concepts if this was coating failure or something like that and that it was fine to use and install them, so I called them and they asked me to send them some pictures of the rotors. They replied and told me they would go ahead and just replace it again. Since they offered I went ahead and said yes and figured having a replacement directly from them I'll for sure get a shiny clean rotor! Appreciate their great customer service and let's hope third time is the charm.

[Redd]

I think you're over thinking it. Any surface imperfection is gonna get ground off the first time you apply the brakes.

[TheMidnightNarwhal]

Originally Posted by Redd

I think you're over thinking it. Any surface imperfection is gonna get ground off the first time you apply the brakes.

I know, I was going to install the new one but I'm not going to say no to a free replacement, I asked them if it was fine to install and it was their first reply to replace it