One of the hardest working parts on a race car is the brakes. Maintenance of this part of our car is often an ongoing affair.

 

If we adjusted our balance bar to tune the braking balance, we need to take a look at where the balance bar is positioned in relation to the two master cylinders. It should be centered, but often is not. If the balance bar is off to one side, we need to think about making changes to the caliper piston and/or master cylinder bore size at the front or rear to help balance the system so we can center the bar.

 

Reducing the master cylinder bore size will generate more force on the pads. Increasing the size of the caliper bores will also generate more force on the pads. The opposite is true for both the master and the calipers. So, you can use different sized bores to balance the system.

 

Let's say you are having to use more and more rear brake to keep the front tires from locking up on entry and your balance bar position is biased toward the rear master plunger rod. You can either decrease the rear master bore size or increase the rear caliper bore size to generate more force on the rear brake pads and then center the balance bar.

 

You can also take force away from the front brakes by increasing the master bore size or decreasing the front caliper bore size. The decision on which end of the car to change might be decided upon inspection and finding one or the other damaged and needing replacement. If the front calipers are broken or worn out, now would be the time to change to a different size on that end of the car.

 

The same is true of the masters. If they are worn and need replacement, think about making changes to the force balance by ordering a different size than what you've been using. Your brake company technical department can help you decide what degree of change will help with your particular problem.

 

Inspection We will need to completely disassemble the brake system in order to do a thorough inspection. But first, we need to look over the complete installation and see if there are any visible conflicts.

 

A conflict is where the caliper rubs on the rim, or the pads are wearing at an angle from the alignment with the rotor being off due to an earlier crash or just hard use. The brake lines might be damaged from work done on the car to remove and replace the engine or suspension parts. We can now decide if the brake lines could be relocated to avoid future conflicts.

 

We can note the condition of the lines including the flexible lines. We need to take a close look at the rotors to see if any cracks or unusual wear is evident. We need to measure the width of the rotor and see if it's within tolerance for the amount of material the manufacturer recommends is safe.

 

The connection between the rotors and the hubs is a source of problems. A lot of heat and mechanical force is applied to the mounting tabs and connectors in these areas. See if you can spot problem areas that can be addressed later on.

 

One problem we ran into with a recent inspection was that we observed a taper in the width of the rotors. The outer half inch was narrower than a reading farther in toward the center. This was most likely due to the caliper spreading out as the brake force was applied to the pads. Interestingly, the pads were not worn to a taper, but the rotor was.

 

As previously stated, we need to note the position of the brake balance bar at the pedals. The bar should be centered within 1/16 inch. If not, think about making changes to the bore sizes in either the calipers or masters or both. Also check the bushings in the brake pedal and make sure there's no excessive play.

 

Note the look of the brake fluid including color and texture. If the lines are rusting, the fluid will be a rusty brown. If moisture has invaded the fluid, the color might be a more milky white, usually more toward the calipers. Check for leaks around every connection and around the caliper piston bores.