Brake fade is an interesting
phenomenon which some of us have
experienced first hand, others probably never have or never will.
Put simply, brake fade is the loss of sufficent friction between the brake pad and the rotor that the pad makes contact with. The resulting loss in friction leads to the inability to slow the vehicle.
How does it happen?
Brake fade usually occurs when you use brake pads in a manner that they were not originally intended to be used. It's caused by the hard or repeated application of the brakes at high speed to stop the vehicle. Over several applications (say four or five) at high speed (above 60mph) within a short period of time (about 10 to 20 minutes or more) will heat the pads up to a point that they become slick or glaze over. *
In organic pads?
Organic brake pads are made out of a glue and a strengthening material, which used to be asbestos (but was discontinued due to the obvious reasons). when you excessively heat the pads/rotor due to hard repetitive braking, the glue begins to soften and melt, making the linings of the pad slick.
What can I do?
Well if you know you're going to be doing some hard/repetitive braking, you can purchase some performance brake pads that are resistant to fade. There's no way to eliminate fade; energy always has to be converted from one form to another, and, in this case, heat. Performance pads are usually quite abit more expensive than regular OEM pads,
but are worth the investment.
Other symptoms which seem similar but occur differently:
If you've ever done some repetitive braking, and you have
performance pads; suddenly you may step on your brake and
it goes straight to the floor. This typically isn't a
result of brake fade, but it can occur with brake fade.
What has occured is that your brake fluid is boiling
within the lines and in the reservoir. Standard DOT3
brake fluid usually isn't capable of handling high
temperatures, you might want to upgrade to DOT4 fluid to
prevent this from occurring. You can do this with no modifications to your vehicle.
I've experienced brake fade on one occasion, it's no fun going down a paved country road through farm land at 120mph to find out that you can't stop. Well you can, but when you look behind you and see all that smoke, that's your brakes.
* Orpheum adds: The area I've seen brake fade most commonly is down mountains. People use their brakes constantly, but gently, and before too long it's all you can smell from the car in front of you.
Things to remember when traveling down a mountain:
All vehicles have a lower gear than the one you are using
that you may safely operate in. "Drive" instead of "Overdrive" in automatics, 5th or 4th gear in standards.
Use these! it'll assist you in maintaing a safe speed and
prevent crashing into someone.
See engine braking.