I have new, the below pictured master cylinder. When I bench bled it, I had to back the center bolt way out to get full travel of the piston. Now that I have it on the car, I cannot get full pedal travel to the floor, and very little fluid movement If I remove the bolt of course it leaks there. What is the center port for? The bolt in there has a stem on it like it is designed to block the piston from traveling. Why?
Also, my pedal returns very very slowly after depression. Not normal.