After my last track event in sebring I have some vibration form my front rotors.

Is there a way to know if the vibration is from them being worn?

 

You probably just have a lot of uneven pad transfer. It's possible the rotors are warped but you would need one of those gagues to measure run out.

 

How many track events have you run on them, what kind of rotors and calipers and pads do you use? It may be that you could "turn" or grind even the rotors if there is uneven wear or very minor warp, if there is enough depth on them still.
But it could be other factors too, such as the pads or calipers. Best to have some one who knows brakes take a look and drive in it for proper diagnosis.

 

OEM calipers (non-brembo). They where used with hawk HPS for 30k miles. They currently have just a 2 day track event on them.

The rotors have a lip on the outer edge, so I know they are worn, but I dont know if to the point as to replace them.

 

Sounds like you may need to replace the rotors, or have them "turned." The rotor surface is just uneven. Its not that big of a deal. Happens often if you are going pretty fast and stomp the brakes, or just heat up the rotor from prolonged use. You have a few options.

 

You don't have any pad deposits on the rotor? That would be the first place to start. Look for them on the rotors.

 

It has a little bit of pad still stuck on the rotor, but the vibration has lasted more than what I've experienced before with pad deposit.

So what is the feeling when the rotors are worn and its time to change them?

 

Take a look at your pads. Do they have sprakling bits in them? They might have vitrified from the heat of tracking them. If they have, they are now super hardened and are litterally grinding away at your rotor.

Consider getting new pads soon. Before the rotors are too worn.

 

Nope I used porterfields for the track event, but at the end of the day I changed back to the Hawks.

 

How long did you drive on the street with the Portefield after the event? Long enough to clear the Portefield's transfer coat ?

 

+1

Mine did the same thing when I was running the OEM brembo brake pads on the fronts. The pads basically got overheated, started breaking down, and left a LOT of pad deposit on the rotor. You can tell by visually inspecting the rotor, you will see black markings on it.

Fortunately the fix is easy. What I did was just put on some track pads (which are abrasive when cold) and drive them on the street for a couple days and it will clean the rotor off. Of course, you could also turn the rotors, but that costs money and wears the rotor thin.

 

I didnt run with the race pads after the event, so I might still have some deposit on them. The thing is that they dont look as though they have much brake deposit on them.

 

Have you checked your tie rod ends and other bushings lately? If you've experienced pad deposit vibration before, and think this may be different, I'd check there while you're under there checking other things. You might have something loose thats vibrating.

 

I havent checked in depth but every thing looks ok. The vibration only occurrs while braking and it is most noticeble at high speeds.

Couldn't it just be hat the rotor is worn more than what the specs require?

 

Follow the stoptech procedure which removes uneven pad deposits using aggressive pads(cold though). Makes perfect sense:

http://www.stoptech.com/tech_info/wp_padremoval.shtml

 

Thanks for the link, I'll try that but I think it is time to change the front rotors anyways.

 

I had pad deposits on my front Stop Techs after a track event you could not detect by looking at the rotors but it made the whole car shake when braking. The fix was Stop Tech send me a set of Hawk Blues that I made several repeated stops just like bedding in a set of new pads. Cleared it right up.Then I sent the pads back to Stop Tech and they charge $50.00 for the rental.

 

Did you ever use your emergency brake when you parked your car? Maybe the rear rotors are warped.

 

Ive never heard of that happening. Besides, I believe the e-brake uses the inside of the rotor, like a drum e-brake. It does not grip the rotor like a caliper, if thats what you mean.

 

^^^That's what I was thinking. But, when I was at the track they warned against parking with the e-brake so I just didn't do it to avoid stupid problems.