Cracked Rotor - Brand New. How?

[kirkhilles]

I just finished redoing my front brakes (new rotors + pads + brake fluid) and I started to work on my suspension and noticed my new rotor was cracked. GRRRR.

Could someone please tell me what likely happened and whether this is a manufacturing defect or something I did incorrectly. I guess I know the answer on whether it needs to be replaced.

I ordered the rotor from RockAuto and believe that I ordered the correct one: CENTRIC 12052002. This is the front right rotor.

Thoughts?

 

[richrootes]

Looks like a manufacturing defect to me - I’d think that Tesla might want a look at that

 

[kirkhilles]

Thanks, I'm hoping so. Its 3rd party (Centric) which is typically a very reputable brand and is often used in OEM applications. I've filed a return with RockAuto.

 

[GeorgeM]

Not 100% certain, but from how it appears in the picture something was trapped between the hub and the rotor. All the cracks radiate outward from one point and the cracks are wider at that "center" point. Entirely possible the rotor was machined incorrectly but more likely some small foreign object got trapped. I am assuming this was noticed after the wheels had been reinstalled, the lug nuts torqued and pressure applied pushing the rotor against the hub. Now that I look closer at the picture the wheels had to have been installed as there are marks from the wheel on the rotor and the crack is into a void in the wheel casting. Something was under that rotor.

 

[kirkhilles]

Interesting, I hadn't considered that. It would make sense.

 

[Gtech]

My best guess is that someone sheared off that rotor retention bolt and didn't removed the rest of it.

 

[kirkhilles]

Haha, ding ding! That was it. Good call.

 

[TonyT]

The new rotor should have a hole for the bolt, if there is one sheared off on the hub, future install of new rotor aligning to the hole should prevent damage. The screw helps hold the rotor in place when calipers are removed. Be careful of the rotor falling off in that condition.