Vibration under breaking

[wasya152]

Did a track event on Monday on my CS, which was just amazing fun and got me hooked, but noticed today that I was getting vibration when braking today on the highway. The wheel balancing seems ok as I don't have the vibration while driving, just when I tap or hold the brakes. What do you think it could be?

Thanks in advance.

[Suds]

Sounds like brake pad buildup on the rotors.
It should clean up over time.

[Sahil17]

warped rotors ?

[wasya152]

I had the dealership replace rotors about a months ago. I think they were supposed to replace the front brakes. Will find out tomorrow.

[Adcampo]

I just posted a similar thread the other day. I had the same issue occur after my second track day of the summer. I took it to the dealer yesterday and they replaced the rotors and pads under warranty!

Not sure if you have CCB's. I have read about build up on the rotors clearing up after a few days of normal driving. I'll be getting track pads to swap out for my next track day.

[maddmatth]

Rotors rarely 'warp'. It's pad deposits from overheating brake pads.

Doing a brake bedding procedure can generally clear it up quickly. Don't piss away money on new rotors or you'll be replacing them every trackday.

You should look into using track pads, as for this to happen you're probably pushing hard enough to for your pads to exceed their operating temp range.

[dodospor]

following

have the same issue and dealer replaced my rotors as well and i cant figure out what is wrong with it checked my brakes at 3 diff places and they say its fine i did ped the brakes and still no luck , mine is not ceramic brakes

[andrei.m4]

Aftermarket brembo pads for example was a pain for me. After a few hard brakes all front vibrate. Sometimes it can be from the pads. Use oem new pad or trw, these 2 models i tested and no issues. Trw are my actual pads and works so great.

[m34m]

Originally Posted by maddmatth

Rotors rarely 'warp'. It's pad deposits from overheating brake pads.

Doing a brake bedding procedure can generally clear it up quickly. Don't piss away money on new rotors or you'll be replacing them every trackday.

You should look into using track pads, as for this to happen you're probably pushing hard enough to for your pads to exceed their operating temp range.

How do you brake bed steel brakes?

[wasya152]

I've driven the car for about 200 miles now. I did a couple hard brake stops on the empty highway, but still getting vibration. It's pissing me off because it's makes driving the car not enjoyable with the vibration under braking. I put on about 100 miles yesterday doing hard driving. Not sure how much longer I need to wait. The car is under warranty ans my dealer won't have an issue replacing them, but I'm planning to do 3 more track events and don't want to deal with it every time.

I'll try again proper bedding procedure on Monday when I get back home.

[maddmatth]

Originally Posted by wasya152

I've driven the car for about 200 miles now. I did a couple hard brake stops on the empty highway, but still getting vibration. It's pissing me off because it's makes driving the car not enjoyable with the vibration under braking. I put on about 100 miles yesterday doing hard driving. Not sure how much longer I need to wait. The car is under warranty ans my dealer won't have an issue replacing them, but I'm planning to do 3 more track events and don't want to deal with it every time.

I'll try again proper bedding procedure on Monday when I get back home.

You need to get them properly hot (but not overheating), and do not come to a stop.

It varies a bit but about 5 hard braking events from about 70MPH to 20 MPH in a row, and then drive for a few minutes to cool them down. Do not stop, and brake hard but avoid triggering ABS or locking up.

[Sunny D]

Did you use your e-brake right after a session? I learned the hard way to never do that. If so, have a close look at your rear discs, I bet you will see the markings from the pad deposits. This happened to me from a track day 3 years ago, and finally just replaced the rear discs this week. Problem solved!

[IVM3]

Originally Posted by Sunny D

Did you use your e-brake right after a session? I learned the hard way to never do that. If so, have a close look at your rear discs, I bet you will see the markings from the pad deposits. This happened to me from a track day 3 years ago, and finally just replaced the rear discs this week. Problem solved!

Hmm the ebrake uses a separate drum brake on the rears. I'm not sure how that would cause pad deposits? I know some cars don't have a separate drum brake and use the regular brakes when you pull the ebrake, but that's not the case with the F8X.

[Sunny D]

Originally Posted by IVM3

Hmm the ebrake uses a separate drum brake on the rears. I'm not sure how that would cause pad deposits? I know some cars don't have a separate drum brake and use the regular brakes when you pull the ebrake, but that's not the case with the F8X.

No kidding. Then I must have sat there with my foot on the brake like an idiot. I had a clear deposit from the pad after my last track day. Just assumed it was the ebrake! Thanks for info.

[wasya152]

Did the brake bedding at least 6-8 times, twice and still getting vibration. It only happens when slightly pressing the brake. I think it brakes ok under hard braking. Any other suggestions?

[BeachieM3]

I doubt this is it, but I had vibration under high speed braking and it turned out to be a lower control arm bushing gone bad. If the car is jacked up see if you can wiggle the wheel back and forth toward you. That was the giveaway we had a suspension issue.[IMG][/IMG]

[wasya152]

So I had the rear brakes replaced and everything is back to normal. I'm pretty sure it was a noob mistake of using the handbrake to park the car when it's cooling off after the session that caused it. Live and learn.

[Jonzny]

Originally Posted by BeachieM3

I doubt this is it, but I had vibration under high speed braking and it turned out to be a lower control arm bushing gone bad. If the car is jacked up see if you can wiggle the wheel back and forth toward you. That was the giveaway we had a suspension issue.[IMG][/IMG]

Link to the new bushings? I don’t see any OE replacements on FCPeuro. All aftermarket ones- worries about NVH

[Jonzny]

Originally Posted by BeachieM3

I doubt this is it, but I had vibration under high speed braking and it turned out to be a lower control arm bushing gone bad. If the car is jacked up see if you can wiggle the wheel back and forth toward you. That was the giveaway we had a suspension issue.[IMG][/IMG]

Which part was this exactly?