Brake pad material transfer?

[matthew_h]

Anyone got any experience of this?

I spent yesterday scooting round Oulton Park in my E30 M3 and had a great day but it was slightly tarnished by brake problems.

The pedal was going very long but this is just down to fluid. More disconcerting and annoying though was the amount of judder I was getting under heavy braking.

Towards the end of the day it was getting really bad with the steering wheel wobbling considerably and the whole car shaking. Brought an end to the day.

I think it might be down to pad material being deposited on the discs and causing the braking surfaces to be uneven thicknesses.

Anyone else had this and know a way to cure it this time or avoid it in the future?

[Trooper2]

I'm thinking that it's the other way around and that your brake rotors were out of paralellism to begin with and thats why the pad material has transfered.

[matthew_h]

That's interesting. How would that manifest itself?

Would the brakes not have juddered before?

[robscim]

This problem was discussed at length in the cerb (I think) forum. Feeling was that a series of long progressive stops would gradually remove the material and all would be well.

I've tried it and I have to say it works on the cerb.

Have a look for the thread and see what you think - you need to make your own mind up but I think its worth a try before you head down the stealers.

Rob

[matthew_h]

Nice one, thank you Rob.

I'll have a look in the Cerb forum and see what I can find.

[GreenV8S]

This site seems to support your theory that it's to do with contamination of the disc surface:

www.stoptech.com/tech_info/wp_warped_brakedisk.shtml

[anonymous-user]

If you've got a dial gauge, you could check the runout on the disc bell to check it's not slightly out of true, being exaggerated by the pad transfer. I presume you haven't stopped with the brakes on when hot?