We ran into a problem pressure bleeding the brake system yesterday. I have the CNC reservoir with the pressure bleeding cap. Fill the reservoir with fluid, pressurize it with a bike pump, open the bleeders until clear fluid, no bubbles is coming out. Close the bleeders and the pedal is really solid. All good so far. Then released the pressure from the reservoir, and the pedal is really soft and goes all the way to the floor. Still plenty of fluid in the reservoir at this point. We sent a pretty good amount of fluid through the system so I have to think we got the air out. Any ideas as to what might be causing this?