phil996cab99

Based on verbal analysis with a mechanically minded friend, his opinion is that my brake rotors are warped. The symptom is severe pulsation in the brake pedal under all braking conditions.

Does anyone have any recommendations on rotor parts (Porsche or other)? He recommends Bendix, based on his satisfaction with them on domestic vehicles (he has never owned or driven a porsche, but he rides a crotch rocket, so at least he's in the ballpark). Also, I need instructions, since I have never replaced rotors before.

My car is a '99 996 cab, street only (no track). Thank you.

Oak

It's probably brake pad depsosition. If you have enough rotor thickness, you maybe able to just change over to Pagid Oranges or another aggessive Pagid pad and do some aggressive braking to remove the deposition. If that doesn't work, I have heard owners that have sanded the rotors diagonaly with a certain type of "ruby" compound emory cloth to remove the deposition. It's quite difficult to "warp" a Porsche rotor, It maybe a worth while investment in time to try and remove the deposition, esp if you have plenty of rotor left.

MJones

If the rotor is warped, you will get a steering wheel shimmy durring high-speed brake application.

One cause of warping is after hard track braking coming into the pits and holding your foot on the brake pedal after stopping.

Oak

MJones, I have had pad deposition and it feels exactly like you explained. "shimmy during high speed braking" I used some track compound pads a braked aggessively a few times an viola! No more shimmy! More times than not it's usually pad deposition that causes the shimmy. Esp with Porsche rotors.

Gretch

Here as a good write up on the subject, which should end the confusion.

http://www.stoptech.com/whitepapers/...otors_myth.htm

Pad desposition is the probable answer.

Enjoy

phil996cab99

Brilliant! Both in theory and solution(s). I will get to work on it ASAP.