In recent years, vehicle brake design has changed significantly. The use of drum brakes has declined. Because of their simpler design, lighter weight and better performance, disc brakes, used for years for front wheel applications, are now a feature on the rear wheels of modern cars.
They are superior in ‘brake fade’ resistance. Brake fade is caused by high temperatures that are generated by repeated hard braking. It occurs when the pads or shoes ‘glaze’ due to the great pressure and heat of hard use. Once they cool, the condition subsides.
Compared to drum brakes, disc brakes have greater air ventilation. Drum brakes would be ineffective if water accumulated in them so they are not internally ventilated. Disc brakes rapidly fling off any water that they are exposed to.