Turn the handle-bar to the left and set the mastercylinder under pressure by holding the lever with a rubber strap to the grip
and leave the bike over night in the garage - next morning remove the strap and sure there will be a good pressure.

There probly is still air in the line ,let gravity bleed them for you take cap off resevoir open bleeder on caliper and grab a drink wait for the fluid to start to flow make sure you keep refilling resevoir or you will have to start al over after refilling 3-4 times close the bleeder screw and reinstall cover and you should be all good