A buddy who has done thousands of brake jobs over his 30+ years of mechanicing always trues new rotors. He has seen pretty much it all over the years. Yes it is and extra step and no they probably do not "all" need it. But enough do in his estimation to assure the job is done right, not just done.
And I would add that almost all shop's never check them before slapping them on.

OP probably as others say it's burn off of the rotor packing/coating, you should clean them really good with brake cleaner before install, that reduces the problem.

As to truing, don't get the animus questioning the one person suggesting this, it's just personal preference. The obvious advantage would be that you'd find out before and thus not have to disassemble the brake job you spent 3 hours doing if it shows up after, if you did this for a living, spending 10 minutes to keep from having to lose two to three hours work revenue and the potential of a customer come back is wise...

quote:

Originally posted by old rugged cross:
A buddy who has done thousands of brake jobs over his 30+ years of mechanicing always trues new rotors. He has seen pretty much it all over the years. Yes it is and extra step and no they probably do not "all" need it. But enough do in his estimation to assure the job is done right, not just done.
And I would add that almost all shop's never check them before slapping them on.

I think you are full of shit, Ive done 1000s of brake jobs over the years and I never machine new rotors, and I have never had a new one show up warped. Even the cheapest of chinese junk rotors are straight right out the box.

To the OP, sounds like you did not clean the oil off the new rotors, drive it some more and get them hot if it doesnt stop after a day or so then you might have a problem.

jwl, did you read my last sentence? Or HRK's post right below mine for that matter?

Just because a very good mechanic I know does what he does. You want to say I am fos. Nice. I am glad my mechanic has done my work, not you.

My guess is you do not own a professional lathe for starters. Then by your own admission buy the cheapest Chicom junk you can find and slap it on. Perfect! Have a nice day.