through my research I also believe that "warped" is a misnomer.
stoptech is about as good of a source of brake knowledge as you are gonna find and it is not "interweb" wives' tale folklore...
anyway, another thing to consider is the over-tightening of lug nuts. this can cause a rotor to be seated improperly and develop pad deposits. i either do not allow shops to rotate wheels or if they have to take off my wheels (say to mount new tires) i always loosen the lug nuts and re-torque to spec.
too many times i have seen mechanics use air tools and then tighten lug nuts in a circle pattern. just laziness.
it could be that due to a hub, rotor, lugnut, and/or wheel design (or any combination thereof) the cx-9 could be particularly vulnerable to this.
from the police fleet manager publication:
http://www.hendonpub.com/resources/article_archive/results/details?id=4819
The most mistaken topic in all of police fleet maintenance is the myth that brake pedals pulsate and steering wheels vibrate because of warped rotors. Of course, rotors dont warp from heat to become wavy like potato chips. Rotors dont warpthey wear unevenly.
The problem of pedal vibration, incorrectly called rotor warp, occurs about 4,000 miles after the brake or tire change. Since it is caused by uneven and not heat, you cant solve this wear problem by better control of the heat, i.e., by the use of specially processed rotors or by the use of drilled and slotted rotors.
Instead, you solve the wear problem by fixing the shortcuts in rotor installation or the improper lug nut tightening.
But the rotors look wavy. Yes, they appear wavy due to either uneven wear around the swept area (if semi-metallic pads were used) or due to uneven build-up of friction material (if ceramic pads were used).
Do you want proof that it is a wear problem and not a heat problem? Measure the thickness of the rotor at the 12, 3, 6 and 9 oclock position. If the rotor has warped by heat like a potato chip, then the thickness will be the same everywhere. If the rotor has been worn unevenly by intermittent contact with the brake pad, the thickness will be differentyou will find one high spot and one low spot.
Further proof of the fact that uneven wear and not heat is one of the more common solutions. The shim put between the hub and the rotor to fix the problem has one high spot and one low spot! Match the high spot on the shim with the low spot on the rotor, and the problem is solved.
Now that you are looking at the problem as a wear issue, what causes it? The root cause of the uneven wear is one of two things. Either the rotor is out-of-true with the hub, which could be a poorly machined rotor or hub or both. Or the wheel was improperly torqued to the hub during the last tire change.
The last step in a professional brake job includes the use of a dial indicator to measure the total runout of the rotor mounted on the hub. It must be less than 0.002-inch, the OE spec for most vehicles. Two, for each tire and wheel change or rotation, be sure to torque the lugs in a star pattern and be sure to use either a torque wrench or torque sticks. Those two steps will virtually eliminate premature rotor wear, period.
