Rotor warp question

Maybe it was just a misunderstanding of what was actually said. Consider this - If you have the rotors turned and wait a couple of years before installing them, at that point if it turns out a poor job was done turning the rotors true you are going to have a tough time taking them back with the complaint 2 years after the work was done.

-jim

On Jun 2, 6:32 pm, jim wrote: If you have the rotors turned and wait a couple of years before

Good point. Thank you.

read this article.

a)improper storage can lead to warped rotors.

b) A lot of vehicles now require machining the rotors on the car, so turning them off the car and storing them is pointless because they'll still have to be machined on the car.

Ray

The problem is not the rotor themselves being warped, but rather the mating surface is not true. You should always have the rotors turned while installed on the vehicle, this way you eliminate the imperfections of the vehicle.

There probably isn't an on-car lathe in this little town. While on-car machining may be the quickest way to a true disc, it is not necessarily the only way.

Most mechanics, I would suspect, never clean the mating surfaces of the disc to hub, nor do they check the thickness and runout. It takes time, but more than that, I would guess that many dont recognize the need for nor importance of doing it.

Old techniques are slow to die out.

I was thinking about this, and is it because the tolerances for warped rotors have gone down or ???

My big old american rustbucket beaters never had warped rotors. My wife's Beretta warps them just sitting in the driveway.

I do sometimes question if new and improved really is new and improved, and in this case, the "old way" of brake jobs seemed to have resulted in a lot less problems with warped rotors.

Sometimes "old school" isn't so bad - it's hard to mess up something that doesn't require precision. I liken it to the difference between the drawing board (CAD screen) and the real world. On the computer screen, your "dog-lick" engineering solution looks really sexy, but in the real world, it fails miserably.

That said, I don't miss carbs. To me, FI is actually simpler to understand and repair.

Ray

It all has to do with the elimination or asbestos pads. For years, we as consumers were taught if we heard brake noise we have a problem. That rule no longer applies with semi-metallic pads. In order to combat the noise issue, manufactures are making the rotors out of softer metal. Which in turn makes them more prone to warping. Just compare rotors from a 04 f150 to a 71 f150.