Posts Tagged: Low Brake Pedal after replacing master cylinder

C027B Low Brake Pedal

Why are you getting a C027B Low Brake Pedal code after replacing a master cylinder   GM has issued a service bulletin #PI0785B to address a C027B code that appears after replacing a master cylinder on the vehicles listed below. GM says the C027B trouble code is most likely due to a missing O-ring that fell off during the master cylinder replacement procedure. The missing O-ring results in a vacuum leak between the vacuum brake booster and the master cylinder causing a low brake pedal and the trouble code. To … Read More