Hi,

I upgrade my 996 TT breaks to a 6 pots calipers and 350mm disc from 997 TT.

After install, every time I brake I feel a stong vibration in the brake pedal and steering wheel.

After this, I install new pads and the problem continue...

Now I install new discs. The car brake fine at low speed. But when I brake in high speed the vibration returns.

What should I do to solve this problem?

Thanks...

 

i also just installed 6 pistons/350mm rotors, i have had a couple weird issues like you.

i also have some juddering at high speeds when braking - this has started to go away but is still present.

i have also noticed that over large crests i.e ups and downs the brake pedal on occasion has kicked back at my foot. this can be quite scary whilst trail braking around a corner.

all these issues have pretty much gone away now, im no mechanic but i think its down to the abs/gizmos syncing. in addition the brakes needed to be broken in.

give them another 200 miles of driving and report back.

i have around 300 miles on my brakes total and im extremely happy with the upgrade. i highly recommend avoiding the oem pads. i drove a car with 6 pots and 350mm and oem pads all the way around. it it felt like the cars brakes were totally stock.

im using pagids in the front and oem in the rear, and the brake bite is amazing. i plan to upgrade the rear pads once they wear out a bit and upgrade to 350mm rotors in the rear!

Btw you can blame Enrrique (F1crazydriver) i drive his car and it makes me want to do upgrades! he is a top guy though!

mike

 

I have EBC red pads at front and oem at rear.

There are more users with this upgrade. Have you the same problem?

Thanks.

 

The PSM makes the brake pedal push back but you can override it by pushing harder, but I agree it can be unnerving.

As far as the vibration under high speed braking, I would recheck that the caliper bolts are torqued to 63ft/lbs. Other than that I don't know what could be making it vibrate unless you are getting pad material buildup on the rotors from high sped braking with stock pads.

 

i will make sure my caliper bolts are torqued down sufficently.

thanks for the advice, mike

 

If it persist, check if your rotors are warped. Had that once on my Merc..

 

This sounds like pads not bedded to the rotors. You need to get pad material uniformly transferred to the rotor for them to work properly. The procedure is described here, among other places:
http://www.braketechnology.com/brakepadbedding.html

Look for a dull, blue-brown color on the rotors to indicate pad material transfer. See photo below.

Jon

 

My vote as well....cannot tell you how often you hear 'warped rotors' and it isn't. Sure, they turn them and that 'fixes' it, but it is just pad deposition on the rotor.

 

the rotors are brand new fellas!

to be honest i just drove the car.. i think all my issues have gone away..

no bouncing pedal or juddering.. they do sound like a freight trane.. but i think its funny.. rolling in the city and people are like wtf

 

Mike - The fact thatthe rotors are new is the giveaway. When rotors are new, they have no pad material transferred to them. Until you get a uniform layer put down on the rotor, the brakes stick-slip when you apply them.

Glad the problem went away. I think this shows that Ard and I had the right diagnosis.

Jon

 

Had the same thing with my new Cool Carbon pads. Didn't have much time to bed them in before a hard day at Laguna Seca. They performed fantastic at first but then as they heated (15mins in) they began to shake pedal and steering wheel pretty badly.

Then upon cooling they were fine again. Then nasty at temp and speed the following runs.

Not sure if I need to turn the rotors (stock) an try to re-bed?

Suggestions?

 

Cost nothing to try a re-bed.

New pads and a hot outing is asking for a bedding/pad transfer issue... one of the cardinal rules with bedding is this: once you get the brakes crazy hot/up to temperature, DO NOT come to a full stop until they cool down...whatever you do, you do not want to have a hot pad sitting in contact with a hot rotor in just one position.

Sometimes a very aggressive pad can be used to 'clean up' a rotor, then rebed with street pads....


Give the bedding a shot, see how it does

A

 

alot of times new rotors are covered in cosmoline. to prevent them from rusting..
if you get a can or 2 of berrymans break cleaner and a towel you can get alot of it off.
fyi you will see smoke for a day or so while it burns off.