Hair-line cracks in brake rotor?

thecarman

Well-Known Member
Joined
Mar 17, 2005
Location
Apex, NC
Has anyone ever seen small hair-line cracks in a rotor like this? I was replacing the front springs in my K30 (D60 front axle) and when I pulled the passenger side wheel, this is what I found.

pics:
http://www.triadfoundry.com/richards_pictures/stuff/disc_crack1.jpg
http://www.triadfoundry.com/richards_pictures/stuff/disc_crack2.jpg

I guess I'll be replacing the rotors now. :( The driver side rotor did not have these cracks, but it's worn badly from where someone in the past must have let a brake pad wear down to the backing plate.
 
thecarman said:
Has anyone ever seen small hair-line cracks in a rotor like this? I was replacing the front springs in my K30 (D60 front axle) and when I pulled the passenger side wheel, this is what I found.

pics:
http://www.triadfoundry.com/richards_pictures/stuff/disc_crack1.jpg
http://www.triadfoundry.com/richards_pictures/stuff/disc_crack2.jpg

I guess I'll be replacing the rotors now. :( The driver side rotor did not have these cracks, but it's worn badly from where someone in the past must have let a brake pad wear down to the backing plate.
Click to expand...
\

hum I wil have to look at mine tonight:confused:
 
thecarman said:
Has anyone ever seen small hair-line cracks in a rotor like this? I was replacing the front springs in my K30 (D60 front axle) and when I pulled the passenger side wheel, this is what I found.
pics:
http://www.triadfoundry.com/richards_pictures/stuff/disc_crack1.jpg
http://www.triadfoundry.com/richards_pictures/stuff/disc_crack2.jpg
I guess I'll be replacing the rotors now. :( The driver side rotor did not have these cracks, but it's worn badly from where someone in the past must have let a brake pad wear down to the backing plate.
Click to expand...


Yep Had them on the 60 in the dodge Think they are in the shop if you want a look.
Was told its heat crack.
Some say its ok to run some shops will not touch it without replacments for them. Also I was running Carbon pads and the new set looked the same in 6 months so I just went with them.
The pads are cut to put more presure (PSI) on the rotor and make them stop better but when you increase PSI heat goes up.
Think that is where the cracking I got come from.
Jon
 
Those are just surface cracks. While they are not a "good" thing, there is nothing wrong. Sure it doesn't hurt to replace them, but those small cracks will not have any negative effects. They occur as the surface is rapidly heated and cooled, as the rotor rotates under braking. I actually had a crack that went all the way through one of my front d60 rotors and it did not cause any problems, I just happened to find it when I had the wheel off.
 
I've had cracks like that in just about every vehicle's brakes I've ever owned, but I tend to drive..umm.. agressively.
 
So I can run it as is?

Because I would love to not have to replace the rotors right now. :)
 
I would..

Oh wait, I AM.. :p Mine have cracks like that too. Mobytruck has alot more "GO" than "WHOA" now...
 
Very Common. Heat stress fractures. You can also fine the same type cracks in Flywheels. From what I see in the pics I would run them. If any doubt at all, have them magnafluxed. If the crack goes all the way thru then no, I would not run them. Fluxing them will show that up if it's is all the way thru.
In my experience, I have found that type of fractures in rotors that were closer to the thin side of good.
Hope this helps
 
New rotors are probably cheaper than magnafluxing, though I don't know how much it is. A new rotor is $44 from Advance for mine, but for that money I would just run what you have.
 
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