Question: New Rotors??

[Donne Trav]

Should ALL "new" Rotors purchased on-line or over-the-counter, be
"turned" before they are mounted on the vehicle? Thankyou.

 

[TedC]

Not that I'm aware of. On all the rotors I've purchased, regardless of make or model, I clean them up with brake cleaner and install them with new pads. I've yet to have a new rotor that was defective. Used NAPA rotors on my 1989 vette, and after 4 years and 12K+ miles, they still look and work great.

 

[DaveH_RRTX]

If you are purchasing rotors from quality suppliers they should never need "turning" before use. The only time you resurface a rotor is when there are gouges, deep scratches or other defects in the rotor surface or in cases of mild warping.

"Turning" a rotor involves a specialized metal lathe that actually removes a layer of metal until the surface is smooth or until the slight warp is removed.

Generally you can only turn a rotor a couple of times before the rotor is unusable safely.

You should always clean your rotors prior to installation no matter what the supplier or source is. Wipe it down with break cleaner before and after installation of the new disc pads and you help eliminate any chance of contaminating the pads with grease or other substances.

Personally, I seldom try to "turn" the warp out of any rotor. It is seldom do-able within allowable specs and there is probably a reason that the rotor warped to begin with ( cheap steel or low heat tolerance). Best for piece of mind and long term health to replace the warped rotor and the opposite wheels rotor with new.

On the other hand; unless the rotor is severely scratched I seldom "turn" rotors to remove the scratch. Now if there are many or multiple scratches or gouges that is a different story.

All the normal caveats apply; buyer beware, mileage may vary. Consult your mechanic or a "certified" mechanic.

Dave

 

[Rex S]

I agree with Dave, also watch out for Made in China rotors with poor surface finish. China rotors also tend to have a lot of junk in the cast iron that result in "hard spots" inside the casting.