As you know, your CForce has a brake system that is said to be the stuff of nightmares. Many have tried conventional means to bleed them and few have succeeded. The highest success rate comes from those who have back-bleed them..that is.. from the bleeders on the calipers back to the master cylinder. A bit messy if one forgets to draw fluid from the master before it overflows. Yours lost fluid, so you need to figure that one out.