If you are impatient and don't want to wait too long for your print to finish you can look for a solution in the E3D Volcano hotend. It is able to extrude filament a much greater speeds than a normal (V6) extruder. But it comes at a price of sacrificing the print quality.
It can happen that molten filament can leak from the hotend. This usually happens when there is a gap between the heat break hotend throat and the nozzle. This is the result of poor assembly of the extruder's hotend part.