[fjmartin]

This issue can occur if the pedal adjustment is too tight. This means that the brake can drag, building heat and then the fluid will expand. As it expands it rubs even more and creates more heat and expands more....until it can seize Eventually it will boil the fluid, glaze the rotor and crack up the pads. You need to check the recommended minimum pedal throw before engagement of the plunger into the master cylinder. If you open the fluid reservoir, check that it's still clear-ish. It can turn black when it gets overly hot.