Just got done installing new rotors and pads on wife's car, and when I went to put the caliper back on, I noticed this ... the rotor is missing a chunk, like someone took a grinder to it and grinded a grove into it. This can't be normal can it? Is this ok to drive, I mean, with the chunk missing, is it going to mess up the balance of the rotation? Will the wheel shake or be unstable? Any advice would be great!! Thanks much!

 

Oh yeah, they're Brembo rotors.

 

wow
i really dont think thats right i have brembos too and dont remember that on mine
is it on all 4 or just this one??

 

I replaced the front rotors, not the rears, and only one of the two is like that.

 

in that case i would def take it back and get a full round one

 

I can't begin to tell you why it is done (balancing the rotor maybe?) but I have seen this on rotors installed on a car. I actually just went into the garage and looked at 4 old rotors that I have in the sitting there to see if one of them has a similar grind mark but none of them do. I think I have one installed on one of my cars.

In any event, you should be fine.

Maybe one of the guys that sells brake parts in the group buy area could help explain why it is done to some rotors and not others.

 

It is definitely the balancing. Most all rotors will have that, unless they're balanced a different way, or they were balanced perfectly when cast. That's why there's a different amount cut out of each rotor. Don't worry about it. The Brembos I bought for my BMW 540 last year looked exactly like that.

Enjoy your shiny new brake hardware!