thats not good! Brakes work with hydraulics. when you pull the leaver, the fluid makes the brake pads contact with the rotor. it sounds like there is SOME fluid left in the lines, but you are dangerously close to not having any braking. you'll need some dot4,5 brake fluid added to that and the lines have to be bled of all air (bubbles of air compress, where the fluid doesn't). compressing air bubbles is what causes you to have to pull the leaver 3/4 of the way. if you don't know how to bleed the brake lines, get some help, its not that its hard, just tricky until you know how. the dial is just to adjust the position of the leaver - kind of like adjusting a steering wheel in the car to be higher or lower. its for comfort. GL