New Brembo rotors, came grooved like a record

[Anthony]

04 Subaru Forester X
I have used the combination of Brembo Blanks and Akebono pads on this car the last two brake jobs with great results, but this time I noticed right away I was getting a lot of squealing. I noticed that the new rotors were cut like a record, it is deep enough that not only can I catch it with a fingernail, I can actually feel it with my finger too!
I didn’t notice this when I was cleaning them up prior to install, anyway, here are pics:

They feel exactly like they look, it isn’t just a visual grooving. I wouldn’t really have noticed but it seems to cause a squeal when the brakes are cold. They seem to stop when they warm up.
It looks a lot like they were cut in a lathe really fast. They are Brembo branded but made in China. I have purchased this part number before but looking at an older picture, there was a crosshatch pattern to them in the past.
So just wanted to share this. What are your thoughts? I am just seriously thinking of leaving it for now, put some more miles on it and see if it smooths out. Unfortunately, I got rid of the boxes already so not an easy return. It’s annoying because they were twice the price of standard auto parts chain rotors, but I have had good experiences in the past with these so I stuck with them. You never know what factory makes things now so past experiences probably don’t matter as much anymore. Should these just be replaced?

Topic

[Rob]

where those rotors resufaced or are they new???
those look like someone resurfaced them and pushed the machine too fast. and did a bad job of resurfacing of them

[Anthony]

they are brand new, I didn’t do any resurfacing. I agree it looks like they were pushed too fast through a lathe.

[Jon]

This is strange that they looked like this in a short time.
I think they need resurfaced now!

[Rob]

[quote=”mst3k” post=172700]they are brand new, I didn’t do any resurfacing. I agree it looks like they were pushed too fast through a lathe.[/quote]
I would have them mesured for there thickness and see if they are still good…. might be how that mfg is making them… personally I would do an exchange for some new ones… but if the thickness is what they say it is then they should be good after the pads brake in the rotors
I have never seen new rotors turned with a lathe most of them are made with a milling machine thats why you see cercal cuts
if the thickness is not what they where advertised as then they are used… and where resufaced,,, so I would check the thickness.. you might be under spec

[Rob]

[quote=”JAlfa” post=172722]This is strange that they looked like this in a short time.
I think they need resurfaced now![/quote]
if you look closly at the picture you can see at the very inside of the rotor and the very outside of the rotor the lines…. now the pad’s cant touch that area so it had to be before the pads where installed

[Anthony]

Thanks for the point about thickness. I didn’t measure it, I don’t have the tool to do that. I’d be shocked if they were really to thin right out of the box. However it is something to consider.
And you are right about the whole rotor having the marks, even where the pads didn’t touch it. This was definitely not created by the pads.

[Alexander B]

I’ve had (cheap) disks come like this too, I just ran with them, it was never a problem, and the grooves got flattened out after a few weeks or so of daily use.

I agree that the milled crosshatch is preferable to a record groove, but as it turns out you can buy the expensive option and still get the record groove, so I guess price doesn’t say anything about manifacture method.

[Author]

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