Caliper rebuild kits aren't...
Caliper rebuild kits aren't expensive, and they can make a real difference in how your car performs on the track. As the rubber piston seals get used, they can work harden causing the brakes to drag. Replacing them can help bring your brakes to like-new working status.
Even if you bleed your brakes regularly, you should consider flushing them by midseason. Simply crack all four bleeders and let the fluid run out (while occasionally topping off the reservoirs in the master cylinders) until the fluid coming out of the bleeders is clear. Often, bleeding the brakes won't get out all the burnt fluid that builds up in the system over time.
Finally, don't just flush and refill your radiator. Now is also a good time to thoroughly clean it. While the fluid is out of the cooling system, remove the radiator and completely clean the accumulation of dirt, tire rubber and oil dry that accumulates between the radiator's fins. Don't use a pressurized stream of water. Instead, use a water hose and allow the water to gently flow through the fins from the back toward the front. The idea is to push any debris out the same direction it came in. A clean radiator will help improve engine cooling through the dog days of summer.
And although it's not technically a fluid, don't forget to check your bearings and repack them with grease. This is especially important if you are racing a dirt car. The dirt isn't a problem so much as water, and dirt cars have to be thoroughly washed every week. If water is able to infiltrate the hubs, it can ruin the bearings. So keeping a check on them and making sure there is plenty of fresh grease will help improve their service lives.
Your braking system performs two very important functions for the racer: First, consistent and powerful brakes allow you to stomp on the binders at the very last minute which can equal faster lap times. And second, good brakes are a safety feature that's every bit as important as your roll cage and seat belts. So you need to take care of them.
Saturday night racing means short track racing. And short tracks-no matter if they are asphalt or dirt-are notoriously hard on the brakes. By midseason your brakes are ready for a full inspection. Since you are going to be flushing the brake fluid anyway, go ahead and pull the calipers so you can inspect them and also get a good look at the rotors. Make sure the rotors don't show signs of excessive wear or heat, which will show up in the form of cracks or "spider webbing" between the gas slots on the rotor's face. Also look for cracks where the hat meets the rotor as well as at the holes for the lugs.
By midseason, it's a good...
By midseason, it's a good idea to flush and replace every fluid (and form of grease) in the car. Most lubricant fluids break down with time and heat. Plus, this also gives you an opportunity to visually inspect much of the car.
Next, take a look at the calipers and pads. The calipers should not be leaking fluid and should not show signs of cracking from flexing. Also check the caliper mounts on the spindles and rearend housing for cracks. If you can spare the bucks-or definitely if you have a leaking caliper-invest in a rebuild kit and rebuild your calipers to restore like-new performance. Fresh calipers should not only improve braking performance, but they also provide better feel at the pedal, helping you to drive better.
This is often one area of the car that isn't thought about until something breaks. But since everything about a racecar is designed to maximize the amount of torque put to the track, the driveline absorbs lots of shock every time the driver picks up the throttle or engine brakes.
Midseason is probably a good time to inspect the U-joints in the driveline as well as the fastener hardware associated with it. There should be no cracks or chips, and the bearings should still turn smoothly without any slop. But, U-joints aren't expensive, so you may just want to replace them no matter what. Mark Richards, owner of Rocket Racing Chassis, advises his Dirt Late Model drivers to replace the U-joints after 500 laps of racing rather than take a chance that a cheap part like that will ruin an entire night at the track. While you have the driveshaft out to inspect the U-joints, also take a good hard look at the yokes on both the transmission output shaft and the rearend.
Your seatbelts should be visually inspected every week, but we are talking about a little more than that here. Most racecars mount the belt system in a manner that parts are hidden from view. Whether it's the anti-submarine strap that runs underneath the seat, or the shoulder belts that run through a hole in the rear firewall before mounting to a horizontal bar that's part of the roll cage, there are probably sections of belt you just can't get a good look at.