You have air in the lines. To bleed this air out you need some one to help you. Start with the power brake booster [some have 2 bleed ports] then the left front, then right front, left rear, right rear. Make sure the master cyl does nor run out of fluid while bleeding. The helper person needs to pump the brakes till they have a good pedal, hold it till you open the bleeder, then let you know when the pedal is all the way to the floor. You close the bleeder, repeat this till there is not any air coming out the bleeder, then go to the next wheel. As I mentioned before, do not let the master cyl. run out of fluid.
I hope this helps you have good brakes.
