I would take your Ford directly to the dealership, it well under warranty. Sounds like you have breach in the brake system, like you have a slit in the master cylinder. I would call and make an appointment with your local dealership.
Are you talking about the parking brake? If this is the case, just know that this brake is separate from your regular brakes and is operated by cables. It's possible that you have a cable that is binding. It's best to have this looked at so that you don't have to wonder if the vehicle is going to stay in place or not.
If you're talking about your actual brake pedal, you want to have this looked at right away. You may have a leak in your braking system.
〉 Answered on Jan 16th, 2009 by Lori Johnson, Owner and Instructor at Ladies Start Your Engines
This sounds like a huge safety issue and I suggest you have this problem corrected immediately. It*s possible you have contaminated brake pads and/or rotors. This would be grease or some other substance that has somehow worked its* way on to your brakes. If this is the problem, the only thing to do is to replace the brakes. It is possible that you could have a binding caliper or air in the brake system. The only way to determine the problem is to have your entire brake system inspected by a trusted technician.
〉 Answered on Jan 16th, 2009 by Suzanne Grego, Technician at City of Philadelphia Fleet Management