We have had a few instances where brake failure has resulted in off-track excursions. As competitors we are responsible for the mechanical condition of our vehicles whenever we enter a race meeting and head out on the track.
Brake Fluid
Brake fluid absorbs water over time and this lowers the boiling temperature. Once the point boiling is reached, gas is produced, and this is compressible. The pedal will feel spongy and in the worst case go straight to the floor.
A commonly available brake fluid has boiling temperature of 260oC when new out of the bottle and this reduces to 180oC with just 3.7% water in it. This temperature may not be reached in normal driving but when racing it will. At the very minimum change your brake fluid at the start of the race season and use only fresh new fluid. Don’t use fluid from that opened bottle dating back to last season. You don’t know how much moisture it has absorbed over the last 12 months.
Brake Bleeding
This product is used by some members:
Start with the caliper farthest from the master cylinder, ending with the closest, do ensure you flush out all the old fluid.
Brake Pads
Brake pads should be removed for checking. The thickness visible from the outside of the caliper isn’t necessarily consistent across the whole pad. Do put the pads back in the same location.
If you do experience brake fade where higher pedal pressure required for the same retardation, consider using a pad that has a higher temperature range. Brake fade is generally caused by the friction material out-gassing and this creates a thin layer of high-temperature gas between the pad and disc which in turn causes the friction between the pad and disc to dramatically reduce.
Rotors
Rotors will typically have a minimum thickness dimension stamped on the outer circumference. If your pads are wearing more on the inner part of the face, then most likely the rotor will also be worn more on the inside. Be aware of this when measuring the thickness.
Drum Brakes
If your race car has drum brakes like the Alfa 33, you should check that the self-adjusting mechanism is working. If it isn’t operating correctly, you will have more pedal travel than is desirable.
If you have any questions or want some help don't hesitate to ask.
