Make sure you limit the movement of the brake pedal with a block of wood or anything that will limit to its normal travel length .Other wise you will ruin the master cylinder when you pump .Also pump slowly evenly so as to give time for the fluid to move along the tubing ,none of that quickly quickly stuff as you wont pump out the old fluid . Why not bleed the brakes correctly any way it lengthens the life of the parts and limits corrosion .