Hello there and sorry for the new topic but I couldn't find an old one.

I own a 997 c4s pdk and I have the following problem..
After I change brake pads (rear and front) I noticed a tremble on braking from around 230 to 100 km. I made about 300km and I then changed the front brake disks as they seemed to be bended. The problem with the tremble is still there.

Is there any idea on what it could be?

Thanks in advanced

Dimitris

 

did old brake pads do the same, ifn they did ur rotors might need some attention

 

I did changed the rotors (brake disks) as well. And they still do this trembling.

 

the problem could be that the lug bolts are unevenly torqued and thus making the rotor uneven. I would also check to see if the mating surface of the rotor was clean and free of any debris that may result in a rotor that is not sitting perfectly flush. I would first try using a torque wrench to properly torque each of the bolts

 

Wrong bedding of new pads with rotors?
Going from 230 to 100 is not something i would recomment when just installed.

Not OEM but after marked rotors and pads?

Mating surface of new rotors not proper cleaned?

Could be any of the above or a combination.

Put a dial gauge on rotor to check if warped prior just changing parts.

 

27/11/2015 : i changed all 4 braking pads with new (after market)
04/12/2015 : i changed the front pads with new OEM because of the tremble
09/12/2015 : I changed the front rotors (disk brakes) OEM. I kept the same pads as i only had 300km whith those

-The matting surface is cleaned.
-The lug bolts have been checked twice.

Is it any change that they need some more km in order to have a flat pads surface??

I really dont know what to think and i am waiting the Porsche propose.

 

Did you buy the correct rotors? Just curious as the rotors for the C4S are the thicker version.

 

The old pads mated to the old rotors. With the new rotors I would think bedding in would be again needed to mate properly. Run properly for bedding in. I agree that 240 to 100 is. It what I would call proper procedure on new pads.

 

Don't look past the obvious. The problem started when you changed the pads. I would change them again. I doubt the lug bolt torque is doing it unless you are not using a crossing pattern when initially putting in the log bolts thereby not having the rims sitting flush. If the rims are flush I don't think torque being off will provide the vibration you are getting.