Notice the wear on the caliper. This is from a tire coming loose and grinding on it. John
After An Accident
This is a worst-case scenario: You're 48 laps into a 50-lap feature and your brake pedal has already gone soft; it's to the point where you have to pump up your brakes to get any type of brake pedal. Out of nowhere, you get turned and slam the outside wall with the driver's side door and left front fender. Once you get back to the shop you notice that all that is really hurt is the body. But at the next race you barrel into a corner, hit the brakes, and all of a sudden you have a major vibration in the steering wheel. What happened?
A few things could have caused this. One, you could have a cracked rotor, but more than likely you have a warped rotor. When you hit the wall, your brakes were already overheating, as shown by the soft pedal. The overheated rotor took a hard hit, and now it's bent or warped.
It is vital to check brake rotors after an accident because of this situation. A lot of times you're not able to see anything. If you suspect a rotor is warped, take it to your local mechanic or machine shop and have it checked out. If it's not too bad, they'll be able to fix it. Also, don't always expect that the other side is fine as well. I took a shot last year on the driver-side door that actually broke the rotor in two on the left front. I replaced it and didn't think anything about the other one. The very next race the car had a vibration. And the right-front rotor was also warped from the accident.
Inspect brake rotors every week, even if you weren't involved in an accident. Something li
Keep 'Em Cool!
Want to extend the life of your brakes and rotors? Then buy a small motorized fan and fasten it to a bracket on the front end of the car. Then position hoses to direct air to the caliper and pads. This will greatly help your chances of not overheating brakes. Even if you don't have carbon-fiber air ducts like the ones shown here, it will still help extend the life of the brakes.
Rotors tend to warp when they overheat. If rotors are warped, new pads will likely have a vibration, leaving you scratching your head. With time, the pads will form to the warped rotors. But this will take a lot of time. If you run the fans on the pads, it'll help prevent warping of the rotor.
Watch Out For Glaze
Another thing that the heat cycles will cause is the glazing over of the brake pads, which will create a loss in stopping efficiency. This will require more brake pedal pressure to stop the car. This is another way that the brakes can overheat.
A simple motorized fan is a great way to keep your brakes cool. John Gibson
What you should do is knock the brake pad out of the cylinder. (Note: Make sure you mark the outside and inside brake pad; if you don't and get them mixed up this will cause a vibration.) See if the pad has a shiny, almost smooth, glaze. If it does, use coarse sandpaper to sand down the glaze. Doing this will extend the life of the brake pads and help them wear more evenly.
The drivers who finish up front on a consistent basis do so because everything on the car is working toward a common goal-finishing as close to the front as possible. Your brakes have to be looked at and maintained every race to have a chance to use them when you pull into victory lane.