Hard brake pedal on Ford Transit 2.0 EcoBlue - vacuum pump failure

A brake pedal that suddenly becomes hard and a loss of brake assistance on an EcoBlue Transit must never be ignored, and the fault has a surprising cause. The vacuum pump that supplies the brake servo is lubricated by engine oil. Debris from a deteriorating timing belt can block its oil supply and cause the pump mechanism to seize. On British owners' forums, a seized vacuum pump is frequently described as an early warning that the wet belt is breaking up. If brake assistance becomes weak, therefore, check not only the pump itself but, more importantly, the condition of the timing belt and the cleanliness of the oil. Replacing the pump without removing the root cause will lead to another failure.