Originally Posted by dshealey
Well, if you look on the Internet, you can find anything. I think that article is Urban Myth! It is bullshit at best.
I have seen quite a few warped rotors, on MY cars. Checked them with dial indicators, and had a few over the years that had distinct runout well over 0.010". Not "wobble", but absolute warpage. That certainly was NOT pad material buildup. I had one that started shaking when I put on brakes (A Mazda MPV minivan), and when I indicated it got over 0.020" warp! It was over about 60 degrees of disk rotation, so it was not inter-vane collapse.
I have a hard time thinking that Carroll Smith is full of bullshit.... he is probably one of the most experienced US race car builders that has ever lived - and he goes back a lonnnnggggg way... Indy, Daytona, you name it - he was THERE.
Cementite deposition, pure and simple. Almost as hard as diamonds and impossible to grind off. Happens immediately - especially if you try to "gently" break in new brakes. Inter-vane collapse is EXTREMELY rare and has probably NEVER happened on a street car.
David, these guys are NOT hacks! They are engineers and build some of the most advanced brakes available anywhere - and indeed currently supply several OEM high end manufacturers. Take a good look at some of the project cars they have done. Old dogs CAN learn new tricks.
The only reason I bring up this article (which I have read several times and urge you to re-read) is that I TRIED to fix a pulsation problem on my brother in law's Ford truck for him over the course of several weeks. I spent hours - and he spent a lot of dough - on resurfacing, new brake pads, calipers etc. Repacked bearings, got out the micrometer, etc. etc. Drove me NUTZ, since I have always considered myself capable of fixing just about anything mechanical... the freaking pulse kept coming back after a few hundred miles.
I finally convinced him to buy NEW OEM rotors (at GREAT expense) and to follow the recommended break in procedure in the article which is fairly detailed. It worked and does work 10,000 miles later, period. No more pulsation. No other way to explain it.
Next up: BIGFOOT marries Madonna!