Question of the week:
"Why does my brake pedal seems hard/soft during street or track driving?
Up front, let me start by saying there's no street or road racing "one-fits-all" brake pad that offers aggressive, no fade stopping power with no dust or noise. That said, lets begin with the two most common problems. If your pedal sinks to the floor and requires cool-down time or pumping to recover then you’ve boiled the brake fluid. On the other hand, if the pedal stays high and hard but wouldn’t slow the car, you’re experiencing pad fade. Also known as “outgassing” which prevents the pad from fully engaging the rotor. You can confirm pad fade and outgassing by examining the pads. Most often its detected by cracks found on the pad surface or even chucks of pad material missing or deformed. To check for boiled fluid, bleed out some fluid into a clear container. If it looks dark and smells burnt, it’s a good time to flush with fresh fluid. Also this is a good annual maintenance process, as boiled brake fluid will accelerate corrosion and generate air pockets as their properties deteriorates. DOT 4 has a higher boiling point but DOT 3 will hold up better if you forget or skip an annual maintenance. If you Race Open-Track you’ll want to replace the fluid before every event.
Picking new pads should only be considered after walking through how you plan to use the car. Autocross? Drag Racing? Canyon Carving? Open-Track Road Racing?
Facts: Modern disc brakes convert energy of moving mass into heat. Heat is properly absorbed into the rotor, not the caliper, and dissipates into the air. Simple brake ducts can help lower brake temperatures. It’s why high-performance systems use thicker rotors and specify curved, directional vanes to further absorb and dissipate heat.
What you should know: Better quality pads have sophisticated backing-plate material and thermal isolators that help keep heat out of the calipers, reducing pad temperatures. Better quality pads will have a higher mu factor or coefficient of friction, meaning the rotors will wear a little faster and create a bit more dust. The newest “carbon” pads will produce more dust and come with a higher price tag. With aggressive race pads you will get squeal under some circumstances, it's the nature of the beast. The alternative is a higher-quality street pad that you’ll swap out for a really aggressive auto-cross/road racing pad for those occasional events. Remember to bed each set and once done, you can swap pads back and forth without worry.Continue reading