i'm pretty sure your system is diagonally split. try bleeding RR>LF>LR>RF ........ also if you do have abs, the actual brake system is seperated from the fluid in the abs unit by the slide piston in the modulator. so dont worry about that.

i think it needs to be bleed correctly or the cup seals in the master are faulty if there are no visible leaks anywhere.....also check the rod adjustment on the master from the pedal, if its adjusted to tightly the pistons in the master wont be able to return far enough in the body and not reach the vent ports.......and if that happens, it'll never build any pressure in the system.