Brake Problem
 

Help please,steering wheel vibrates when I brake so replaced front rotors and pads and the problem went but after 6weeks 2thousand miles the problem returned so again fitted new rotors and again the problem went and the steering was fine but after approx another 2thousand miles the vibration is back,cant find anything wrong with the rotors or pads so this problem is driving me nuts,any help would be fantastic.PS I dont brake hard and have checked all the tie rods etc

1. Check to be sure the front struts are tight at the fender mounts
2. Check the balance on your front tires

Sticky pistons in the calipers can cause improper pad pressure on the rotors too. Did you seat the pads too the new rotors properly. This you do by getting on a stretch of highway and get to a speed of about 50MPH...then hit your brakes hard but not locking them up...do this about 3 times to seat the pads. :cheers:

What brand of rotors and pads did you use.

Are you using the correct torque on the lug nots and tightening them in a star pattern?

brakes
 

HI thanks for your reply,did bed the brakes in both times and were fine for several weeks then the shudder on steering when braking started again,I know if I replace them again it will be fine for a while!! people seem to think it mey be tie rods etc but cant be anything else but the brakes cos its fine when I replace the front rotors,it seems to be the left hand rotor because I replaced this one first and the problem went,pistons on the calipa seem to work but dont no what there like under load.many thanks John

Are you using Porsche-brand rotors and brake pads, or something different?

Brakes
 

Hi am using QE discs and pads!

That could be your problem.
I'm not familiar with QE brand, but I've seen several customers with cheap aftermarket brakes have the same symptoms you have.
New components, everything is good. A few thousand miles and steering wobble.
The problem is generally that brake pad material transfers to a disc if the brakes are applied and maintained after stop while the disc is very hot.
This pad bonds onto the disc and every time the disc spins around the material will give it a little more grab and therefore pulls to that side.
I've also seen it happen with OEM pads and rotors while on the track.
For people that generally attend track events, try to use the brakes the least possible during your last cool-down lap and as soon as your car has come to a complete stop take your foot off the brake to allow both the pad and the rotors to cool down.
Happy Boxstering,
Pedro

Thanks for reply,what I dont understand is if the pad material transfers to the disc why with all the cars I have owned has this not happened to me befor!! is it a porsche thing! if I sand my discs down and take it for test run and its fine then
I will be convinced.Will then buy porsche discs,what do you think!!!! regards John

What I don't get, and I see this over and over, is people buying a high-end sports car like a Porsche and then equipping it with the cheapest aftermarket crap they can lay their hands on. I just don't understand that whole thought process.

No one else on this board is complaining about brake pad transfer except you.
So it's not a Porsche thing.
I also will go out on a limb and say that you're the only one using that particular brand of brakes, so it's a QE thing!
I don't know about what other cars you've used those brakes on, but very few cars in this world clamp down as hard as a Porsche with Brembo 4-piston calipers.
I agree with what's been said: You have a high-performance car. For your own safety and the safety of others, you should equip it with high-performance brakes and tires.
Happy Boxstering,
Pedro