Like Mike said, you probably have air in the line that is not moving...a lot of times it will hang up at the banjo nut on the master cylinder, try cracking the bolt and be sure to have a rag under it to catch the fluid...it's not uncommon after you completely drain those lines to get all the air out, I found holding the clutch lever back while I'm working the vacuum bleeder helps, I've had them come back a few times using that procedure.....I've even bled them with no results and tied the lever back and left it over night, this allows the air in the line to raise and escape into the master cylinder, sometimes it works sometimes it doesn't...just keep bleeding and it will come back...
