Brakes

One of the more common causes for the brake pedal going to the floor is a loss of brake fluid. When you're out of brake fluid, your brakes simply won't work. This is pretty easy to diagnose: You should be able to see brake fluid underneath the car if there's a leak in the system. Another possible cause is a bad brake master cylinder. The master cylinder is where brake fluid gets compressed. Pressure on the brake fluid causes the brakes to be applied to the wheels. If your master cylinder doesn't work properly, or only works sometimes, you're going to lose braking power, and occasionally your brake pedal will go all the way to the floor. Another cause can be a bad brake booster. The booster is a mechanism that uses vacuum pressure to take the force being applied to the brake pedal and amplify it. If the booster is bad, then the full amount of force needed to activate the master cylinder and pressurize the brake fluid isn't going to be there. The pedal will go all the way to the floor and the car will be harder to stop. All in all, I would get your breaks checked out right away by a professional mechanic if you do not know what you are looking for just to be safe.