The only purpose of the Ford brake line and hoses is so the appropriate amount of pressure can be transferred from the brake master cylinder to the calipers and wheel cylinders in your braking system. This is done to assist you in stopping your vehicle. Of all the brake lines and hoses, formed metal lines run to portioning valves and T-boxes and a brake hose is used to connect to the calipers or wheel cylinders on your Ford. The hose portion of the braking system will become cracked over time and need replacing. The metal lines of your Ford brake lines and hoses should last longer but can still need replacing. This replacement will occur if moisture enters this closed loop system and corrosion takes place on the inside of the hose. They can also leak because of rusting from the outside, though this typically happens more when vehicles sit for an extended period of time without being driven regularly. When replacing any of the brake lines or hoses, once the repair job is completed on your Ford, the braking system will have to be bled of any air that might have become trapped in it. This bleeding should occur with the longest connection of the brake lines and hoses. This is usually the rear passenger side first, and then the next one to do is the driver side rear brake line. On the front of your Ford, the passenger's then the driver's side should next be bled. If this order is followed, then all of the air trapped in the brake lines and hoses will be removed. This will make it possible for your vehicle to have excellent braking power when you are traveling down the road.