Question: Rear rotor cracks

[hilltek]

I have just noticed both rear rotors on my '97. Have 73K miles and they look to be the origional rotors. Both have what appear to be hairline cracks - radially and one to two showing on the pad surface running area only. I cannot see any depth to them so they must be minute fractures of some sort.
Has anyone else experienced this or can someone tell me if this is a big concern, or what causes this? This car is driven street only and gentile for the most part. Never had this on any other Vettes I've had or any other car for that matter.

 

[Rex S]

It's called heat checking and is normal in HD truck brake drums but not in cars that live "gentile" lives. The brakes have been hot numerous times either by a previous owner or you brake agressivly and don't realize it. A friend of mine's wife gets one year from a set of rotors on her daily car and swears she doesn't drive hard. Anyway, keep your eyes on them as the checking could become cracks as they indicate internal stress in the cast iron.