There is a spring inside the master cylinder, but also on two different setups I've seen for a single cylinder master there's also a fairly strong return spring that attaches to the pedal and then the frame (there should be a small hole on the pedal lever) ... do you have this spring and is it just too weak, or is it missing? Also, what about just adding a 1/2" spacer between the stoplight switch and the firewall?
