Heating up the rotor, and then shock cooling part of the rotor can warp it quite nicely as well...
I was driving in the city, and some idiot cut me off and slammed the brakes for some reason... I had to really pile onto the brakes to stop in time. within about 40 seconds, I got stopped in a big puddle at a stop light. The next time I used the brakes, I could feel the chunk, chunk, chunk that warped rotors have...
Kinda funny, I have driven the car for over a year like that (I have the parts, but the problem isn't really severe... It's not causing nosedives or anything), and at certain temps, they don't do the chunking... Between about -8C and +6C, they are perfectly smooth...

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All it takes for evil to prevail is for good men to stand by and do nothing.

Too many people tip toe through life, never attempting or doing anything great, hoping to make it safely to death... Bob Proctor

'95 S320 LWB
'87 300SDL
'04 E500 wagon 4matic