Notice the glowing red discs....
Notice the glowing red discs. Any doubt that brakes require special attention post-race? NASCAR
I hate brakes! I hate the fact that I have to lift my foot off the gas pedal and slow the car down as I reach the corner. I would rather keep the gas pedal mashed on the floor and not have to worry whether or not my brakes are still going to be functioning at the end of the race. But I don't live in this fantasy world. Like many of you, I race on short tracks, where brakes are so crucial to not only how well you stop but also how well your car is handling.
If you ignore your brakes all season, no matter where you are racing, you will encounter huge problems. Your brakes will give you an indication when something is wrong, whether it's a warped rotor or a soft pedal. We will analyze the brake system and show you some ways to avoid the most common pitfalls.
When you hit the brake pedal, you push one pedal that works two different master cylinders-one for the front brakes and one for the rear. Most of the time this action is controlled by a brake bias controller that will allow you to adjust how much brake pressure is being applied to the front and rear brakes.
If you have too much front brake pressure, the car will have a tight condition when the brake pedal is being pushed because of the front tires slowing down at a greater rate than the rear. Or just the opposite if you have too much rear brake: The rear of the car will try to kick out and act as a loose condition entering the corner.
This will differ if you're running on asphalt or dirt, but I would recommend starting where your brake manufacturer recommends. For instance, I start at 70 percent of front brake bias and 30 percent rear. When I get to a particular track, as soon as I can during practice, I start cranking rear brake into the car. I will do one turn on my dial adjustment until the rear of the car tries to step out on me. Once it gets a little loose, I put one turn back in the front. This will ensure that my rear brakes are being used as much as possible and the brakes should not hinder the way my car drives.
A set of glazed-over brake...
A set of glazed-over brake pads. Notice how the top of the pads have a shine to them. It's easy to remedy this. Simply sand them down with a piece of sandpaper. John Gibson
Change The Fluid
Brakes will heat up to optimum temperature and sometimes beyond, then cool back down, only to have the process start all over again the following week. The fluid in the brake lines will get extremely hot and overheat. If there's any water in your brake fluid, or if you're not using a quality fluid, it will actually start to boil and put air in the lines. This causes a soft pedal. It is excellent practice to bleed your brakes before every weekend of racing. This will not only ensure that your brake lines have no air in the lines but will also put fresh fluid in the calipers.
Remember, the fluid you see in your master cylinder will never make it to your brake calipers unless you bleed your brakes every weekend. If you don't, the same fluid will be going through the heat cycles we discussed earlier and will cause a soft pedal.
The Dreaded Hard Pedal
We just spoke of a soft pedal, but even worse is when the pedal doesn't change but, if anything, acts a little stiffer, yet the car isn't stopping as well. This is easily summed up-your brake pads are worn out! To make things worse, your natural reaction is to push down harder. But all that is going to do is make the pad try to work harder. This will make it overheat and make it even harder to stop the vehicle. The best thing you can do is make sure you pump up your brake pedal, then if it gets too bad, call it a day and save your car from ending up against the wall.
This is a common high-dollar...
This is a common high-dollar brake system. John Gibson
Your brake lines have to be...
Your brake lines have to be checked every week to ensure that they won't leak and cause a soft pedal. John Gibson
It's a good practice to bleed...
It's a good practice to bleed your brakes before every event. However, make sure you don't round off the bleeder-valve. John Gibson
Notice the wear on the caliper....
Notice the wear on the caliper. This is from a tire coming loose and grinding on it. John Gibson
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...
Inspect brake rotors every week, even if you weren't involved in an accident. Something like this could be overlooked and cause bigger problems down the road. John Gibson
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 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.