Thread: The mystery of the warping rotors....

Originally Posted by SteveFarmer

Hi

Being a little obsessive about torque settings, I generally use one where LR give the specs, and wheel nuts is one of those.

Warping is also caused by hard braking which heats up the disc to red hot, and then stopping without letting the discs cool by continuing to drive.

Steve

Also after a hot/hard stopping its not good to keep the pads applied to the discs as the pad can "cook" to the disc causing a tattooed image of the pad on the disc which results in an uneven thickness to the disc which then builds up with added pad deposit thus compounding the problem which you feel as a shudder , so not actually warped at all ( in this case )
I would imagine that one cause of warping could be rapid cooling as in a water dipping .

If the disc was very hot and the brakes applied for a few minutes, could the disc cool unevenly; just like stopping a hot disc in hub depth water.

Originally Posted by benji

If the disc was very hot and the brakes applied for a few minutes, could the disc cool unevenly; just like stopping a hot disc in hub depth water.

Sounds plausible. however the pads would also be hot, so would the pads be keeping that part of the disc hot or allowing that part of the disc to dissipate its heat before the rest of the disc. The disc half in water is easy to see.

I imagine the pads would keep the disc hot.

Hi

That article seems to suggest it is a layer of the material from the pad which gets stuck.

When I put my new front discs on, I had to bed them in. This is one article

How to bed in your new brakes for street/urban driving - EBC Brakes

Steve

Originally Posted by p38arover

Thanks Wayne, just ordered a set of fronts. Maybe I should have ordered rears, too. Do you think they are genuine Brembo?

Ill guarantee you genuine Brembo rotors made in china
Your hard pressed to find any brand rotors that are not made in China

[QUOTE=SteveFarmer;2145901]Hi

That article seems to suggest it is a layer of the material from the pad which gets stuck.


I think that is what I was saying, I was certainly thinking it.

"pads applied to the discs as the pad can "cook" to the disc causing a tattooed image of the pad on the disc which results in an uneven thickness to the disc which then builds up "


As for the bed in technique , who does that ? This would apply to a brand new car also . Imagine the dealer selling a car to you explaining all that, he'd scare you off and you'd finish up across the road buying a Jeep. Not.

I bed my brakes in when they were replaced. It prolongs their life and prevents the uneven wear patterns caused by hard braking. The first thirty stops are the most important - you don't want to get them too warm.