Here we have listed some of the parts that go to make up the figures we have produced and the frequency that these parts might fail – This list is not a complete list of what is covered under a Warranty Direct policy but an indication of frequency of failures Master cylinder; brake servo unit, diesel vacuum pump, callipers, wheel cylinders, pressure regulator, ABS pump and control unit. ABS pressure reducing and proportioning valves, handbrake lever and assembly; handbrake control cables and linkages, brake pedal assembly, self-adjusting mechanisms, brake pipes and hoses.