A customer recently brought his Ford in for service. At the time he was informed he needed new bakes front and rear. The customer declined the repair, citing “I can do that myself”. No problem at all, give us a call if there is a repair we can help you with.
A couple weeks later the customer returned, asking that the brakes be bled. He had replaced the brake pads, and had the rotors turned, but ever since the brake service he had a spongy brake pedal. Not knowing exactly what when wrong, we complied with the request and found that no matter how much the brake system was bled, the pedal was not quite right. The first time the pedal was depressed, it was soft, nearly going to the floor. If the pedal was pumped, the brakes would operate normally after the second or third pump. It seemed to be the classic air bubble, or a bad master cylinder. The question remained, why can’t we bleed the bubble out, and how could a brake service cause a bad master cylinder?