Brake Fade.

being a poor 2.5 WRX owner I have suffered this, only once in a year, but enough to make me wonder what happens.

Obviously bakes work on friction, what causes the friction to fail?

Thought I'd start a topic that might be interesting and only possibly be slagged off for...

 

Heat

 

No **** sherlock!!

real science

 

;-)

The reduction of friction termed brake fade is caused when the temperature reaches the "kneepoint" on the temperature-friction curve and gas builds up between disc and pad. [All brake lining is cured under mechanical pressure following a heating & cooling curve backstroke, heating the friction material up to 450°F to "cure" (cross-link) the phenolic resin thermoset polymers: There is no melting of the binding resins, because phenolic resins are thermoset, not thermoplastic] In this form of fade, the brake pedal feels firm but there is reduced stopping ability. Fade can also be caused by the brake fluid boiling, with attendant release of compressible gases. In this type of fade, the brake pedal feels "spongy". This condition is worsened when there are contaminants in the fluid, such as water, which most types of brake fluids are prone to absorbing to varying degrees.

 

as above "fade" is not one symptom or affect..................it can be influenced massively by pad/disc choice and b/fluid spec as well as poor servicing regimes (old or contaminated fluid, sticky calipers, etc.)