Brake Help!!!

I have a 2001 Mazda Tribute with braking problems. The pedal starting going to the floor. When I started looking at it more closely, I noticed it had no brake fluid. I traced all the brake lines, there are no signs of a leak anywhere. I added some fluid and am trying to bleed the brakes. For some reason I can't get a solid stream of fluid to come out the bleed valves. All I am getting are a lot of air coming out. Is there something special that you have to do to bleed the brakes? Does anyone have any suggestions? Thanks in advance.

If you havent found out already, and since its brake related I hope you have, your master cylinder is leaking into the brake booster canister. You may be able to replace the master cylinder and take care of the issue, but you may also have issues with the booster. If the booster is leaking intarnally, that can cause vacumm on the master cylinder sucking fluid in and then burning it in the engine. If that is the case there can be a slight amount of smoke and a foul smell at the exhaust.