Pontiac Repair: Brakes, power brake booster, vacuum leak

Question
The master cylinder has brake fluid in it. When you hit my brakes they go to the floor and it sounds like air. Where do I need to start to look to find where they are not working at?

Answer
Hi Carrie:

You may have an issue with the power brake booster. The air sound may be a vacuum leak though the booster. As for the pedal going to the floor It could be related but I doubt it. Either way it's not safe to drive if the pedal goes to the floor. what model and year car is this?