This video is about replacing the master cylinder on your MGB. When installing new brake pads and having to bleed the lines, it’s a good time to consider installing a new or rebuilt master cylinder. The job requires a handy rag or towel for capturing any spill of brake fluid. It’s very harmful to your cars finish – and anything else it reaches. Even with your caution, the job is easier with a helper to push the pedal during the bleeding process. And you must be aware of the sender unit that should be removed. It’s on the side of the master cylinder, and has a stem that sticks out – into the sliding piston. It will hinder your bleeding process if not removed (replaced by a plug). Then the piston will travel to pump fluid to the lines – pushing trapped air escape. You should end up with a stiff pedal that properly actuates braking action.