Sounds like a problem w/the master cyl piston not developing pressure. If you aren't even getting any static draining w/the master cyl filled & the caliper bleeders open, then i think you may have an obstruction.
Remove all fittings & lines, use compressed air thru them to verify the openings are clear, reassemble & fill again. You can pre-fill the calipers & then install the lines, make sure all are tght, open the calipers' bleeders & in a minute you should get fluid driping out the bleeders (use clear plastic tubing to prevent a mess/contaminated pads). This is the static bleed. Close the bleeders, fill the master cyl, & either use the MityVac or do the "pump/hold lever pressure/open the bleeder valve, see fluid flow/close the bleeder valve, release lever pressure & check the master cyl fluid level." i just rap on the splitter junction w/my 3/8" ratchet, do the same to the master cyl banjo bolt, & pump repeatedly the lever, then repeat the bleed sequence, a few sessions of that & you should have a good firm lever. If you don't then i would look at a collapsed hose (internally) or your master cyl piston is not sealing (bleeding internally).