Refill Front Brake Line

I have completely drained and cleaned my front brake line, caliper and MC and now wonder what the trick is to refill the entire line with brake fluid? After I put all the pieces back together, I filled the MC with fluid, squeezed the brake handle and nothing seems to happen. I have bled the brakes before without issue, but this is the first time I took the entire system apart, drained it and cleaned it all up.