Brake Analysis Help

[LmeaViper]

Huh, I never saw this thread back when it started. In Sept, on my GTS I was running a full 30 minute session at the track and boiled the brake fluid I had in it (wildwood 570 and an a good front pad). The next time I drove the car I had what I called a groan in the brakes. I can even fell it a wee bit in the pedal if I really pay attention....drives me friggin crazy and I swear it was coming from the passenger side. So now every time I go out, I am on and off the brakes in neutral to try and figure out WTH is causing the groaning.

I did some poking around and couldn't find anything that stood out as looking unusual. However, I never pulled the pads, but will next time I have the wheels off. Then clean up the rotors and see if that helps.

[esm_viper]

So I just installed and bedded Carbotech pads on my car. XP24 and XP10. I did 10 moderate stops from 60mph and 10 hard stops from 80mph then drove home. When I turned around after the 10th 80mph stop, there was some smoke coming from the passenger rotor. This is what the rotors look like after I got home, by the way both front rotors look like this and the back rotors are still pretty clean. Does this look ok or normal?

[esm_viper]

Nevermind, I emailed Mark and he answered my question.

[ViperGeorge]

Smoke while bedding brakes is normal. Porterfield Brakes (one of the best) recommends 10 stops from 60mph, drive 20 minutes without hitting brakes, then 10 stops from 100mph, then drive another 20 minutes. You don't have to go 60-0 but 60-10 is good. Ditto from 100.

[esm_viper]

Thanks for the reply! I haven't driven it since parking the car after bedding the brakes. Mark says I'm good to go and the pad transfer is normal. Less than 3 weeks away from trying out the new pads and TA sway bars and alignment at COTA!

[BlueAdder]

You aren't kidding about the noise, it became like nails on a chalkboard for me. I decided I wasn't worried about sanding too much or causing an uneven surface myself because there's no way I could make them worse.

Side note - The new XP20 pads in front do squeak a bit coming up to a stop. But I find it livable, especially if they will hold up better at the track.

The carbotech do squeal quite a bit when you come to a stop. I have the XP12 on my Focus and every single time I stop it's quite atrocious. I don't really care but people around seem to wonder what's going on.
That being said, the Carbotech are my favorite pads hands down. At the track they are just amazing. Carbone Lorraine (AKA Carbotech in the US) makes the brakes for the TGV (French bullet train) and they know what they're doing. I got those pads on my Elise as well.

I had Hawks on my Focus but I replaced them earlier this year because I didn't care for them that much at the track.

[esm_viper]

So after 2 track days in a row with the Carbotech pads, the brakes worked perfect on the track for 7 sessions and on the 8th session I ended up with a vibration only under braking. Even driving on the street lightly braking I can feel the vibration. I cleaned up the rotors with one of those flex hone tools you attach to a drill. They looked better after sanding but I just went for a short drive and the vibration is still there. I did NOT re-bed the pads and rotors. Doesn't matter if I'm slowing for slow or high speed, it's there every time.

Is there anything I can do to get this to go away so I don't have to throw away rotors that have only 3,000 miles on them? Below is what they look like now. I plan on keeping these rotors with stock pads for the street and switching out to a track only pad and rotor set up.



Edit: I'm taking the rotors to Andy @ Viper Exchange next month to have them re-surface the rotors and see if that helps.