Will...You didn't do anything WRONG! Look back at what I first posted.

Those rotors were just poor castings. I owned over 20 MB's & never had a warped rotor! EVEN on my racecar! Even in the rain at 140mph!

But that darn Toyota tow truck warpes them all of the time.

You can have then turned (trued) & hopefully the problem won't come back.

I don't care what anybody says, if you don't use a torque wrench on them and set the proper torque, they will warp eventually.

Rubbish. I have never used a torque driver on any wheels on any car I've owned, and only on this MB have I ever had problems with discs. Thats Vauxhalls, Audis, Volvos, and a TVR.

I had a pulsating pedal problem and was convinced it was a warped rotor. I checked with a dial indicator/fixture and there was no appreciable run-out, or what there was was well within spec. I removed the 2 relays from the ABS master 'box' to disable the system and the problem disappeared.

From a mechanics perspective
 

I am ASE certified and for many years worked as a Front End, Brake & Power Steering Specialist. Brake rotor warpage is a problem that has been ongoing since eliminating asbestos in 1990. That's not to say it didn't exist proir to 1990 but it was usually caused by abusive driving, mechanics with uncontrolled air guns, cheap pads etc. One of the problems after 1990 was that the pad material would actually weld itself to the rotors causing pulsations.

Additionally, in the past few years many smaller producers of quality automotive parts have been bought up by conglomerates and as a result quality has suffered. Many of the old trustworthy aftermarket brands have sunk to a new low in quality or just dissappeared. Most all of those left now import from China or Mexico which tend to be inferior. Raybestos still has American or Canadian made rotors as of the last time I bought them. These are still good quality. However many parts houses sell "White Box" Raybestos rotors which are from China or Mexico. Avoid them like the plague. If you follow these rules you will minimise the possibility of pulsation problems.

1. Buy strictly OEM or known quality aftermarket rotors

2. If possible OEM or "Ceramic" replacement pads.

3. Rotors should never be machined below tolerance specs.

4. Wheels should be tightened in a star pattern with an appropiate "Torque Stick" if using an air gun, or torque wrench if by hand

5. Break-in of new pads should be "Gentle" for the first 200 miles. Avoid panic stops. Several slow stops from 45 to 0 with cool down time in between helps the process of eliminating high and low spots in the pads so that the full surface of the pads contact the rotors and help dispense the heat.

It is still possible to have pulsation failures when you follow these but at least you've done all you coould do to prevent it from happening. HTH.

Mbdoc
 

I wasn't countering your post; I was countering someone else's

I'm with you on this. The MB is the only car that had NEVER warped a set of rotors until now. I'm thinking I probably did get defects.

Will have them turned at my 160k service.

I wonder if,,, when a rotor is replaced, if there is a small chunk of rust or other debris inbetween the rotor and the hub could cause warpage. Sounds plausible to me.

Try a Honda.
You will change the rotors more frequently than the pads. ;)

I've had 2 Hondas and they warped them every 5k