hairline fracturing in front brake rotor
 

I went to swap in my track pads (Winmax W5) last night to get ready for a track day this weekend and found my front rotors looking like this:

https://imgur.com/tTypskf

(I'm getting an error trying to attach the image... "Upload failed due to failure writing temporary file.")



hundreds of tiny hairline fractures.

I don't have a lot of track car maintenance experience but in all my normal vehicle maintenance experience, I'd never seen anything like it. I'm guessing it's from rapid heat expansion and cooling? Both sides of both front rotors look like that. Is it bad? It looks to me like it's about to come apart in a million tiny pieces, hahha.

Picture isn't working, but if i saw cracks in the rotor on my car i would NOT drive it and I would have it replaced immediately. Don't want to have them fail while you're driving and end up killing yourself or someone else.

EDIT: I guess picture link was added. Doesn't look bad

Sounds like time for new rotors.




Now that I can see the pic, your fine.

I don't think that's it. take a look at the picture I linked.

Replace your rotors. Centric blanks are my preference for 95% of applications on these cars.

That's normal, nothing to worry about.

It's just surface crazing and will wear down smoothly over time and use.

Like these?
http://www.autoanything.com/brakes/6...RoCcB8QAvD_BwE

This ^
As it says your pads are not removing the heat efficiently leaving the scary looking but totally harmless marks.
At work (we make rotors) we get attempted warranty claims for this all the time. It is a total non issue.

I did. And it is. I'd run them. But there's no accounting for not feeling confident in your gear, so if that's the case, replace them. But you're likely going to get the same results.

Are these stock rotors? How many miles? How many track days?

Thickness is more important than how the surface looks when it comes to deciding whether or not to replace them. Measure your rotors.

If you think you have cracks drag a fingernail across them, if your fingernail catches you have cause for concern, but if it's just a bit bumpy it's fine.

These things are stout as fuck, 63k DD miles and 5x track days on my OE rotors.

It's heat checking. It's normal from track use due to the high temps your stock rotors see. I would replace when one of the cracks reach the edge or is large enough to catch a fingernail. Another way to test is to check the minimum thickness of your rotors. I would carry spare rotors on you.