brake judder /pad deposits
 

I have almost new (<6 months and little use) brakes on my S. I fitted EBC yellow front and some porterfield to rears....perhaps not the best match admittedly but I got them at a good price.

I did some stops and cool downs to bed them in.

Considering they are all new, the brakes are crap, and I must have pad deposits asbo get judder under heavy braking, and when braking in town to a halt, I can feel the retardation ebbing and flowing as the pad passes differing parts of the discs.

I dont know if it is the rears or fronts or both.

I drive hard and they do get used but they haven't seen the track yet.

Why do I have this problem?
I recently drove a box stock 2.7 with new discs and cheapo street pagid pads and the brakes were much better than mine...feel and retardation. Can't comment on heat capacity.

When you say "new brakes", I am guessing you mean pads, and all other components stayed the same.

The only time I have experienced brake judder was after changing brake pads to a compound that was not compatible with the compound that I had been using, which remained embedded in the brake discs. Mine went away after a few hard racing laps though.

The OEM pads are actually pretty good stuff. I would not scoff at them. All of the Pagid compounds are known to be compatible with them.

Sorry....no...all new, discs and pads

What sort of rotors did you buy. It sounds like a rotor is out of spec possibly has a slight warp. Some of the guys I track with run a full race/track pad on the front and ceramic blend on the rear they say it give a better brake bias. I haven't tried this, but two have been running DE, racing, and Instructing 20 + years in Porsches, so I trust what they say. I don't believe from your comments its the pads, I personally have had very good luck with the EBC pads.

With that said can you feel any slight tug or vibration on the steering wheel? If you do then my best guess would be something in the front. If you feel nothing in the steering wheel under braking then I'd suspect the rears. Last have you torqued the wheel lugs all the way round, a couple just slightly loose bolts on a wheel will feel odd under braking.

Sorry if this doesn't help, good luck.

Good quality rotors...think they were Pagid...maybe sebro.

Can't think I've got then hot enough to warp...I have gt3 ducts..and has only one been street use so far.

Thanks will look at all the above

Rotors warp if you stop for some time after heavy braking with your foot on the brake pedal. Such as waiting at traffic lights.

The heat doesn't dissipate as well from the rotor when the brake pads are touching the rotor at rest, this is common on all cars. This leads to brake rotors warping due to the different rates of cooling across the rotor.

I suggest that you get the rotors measured for run-out (measure the extent of the warp), they can be machined in situ with the right equipment to true them up or remove the rotors and take them to a machine shop to be machined flat again.