It is the Lincoln Brake Lines and Hoses that make it possible to transport the pressure of the braking system from one point to another. The brake lines are made of metal tubing while the brake hoses are of a hollow polymer tubing construction on your Lincoln. When either the brake line or hose has a rupture in it, the brake fluid will leak out being replaced by air.
Of the Lincoln brake lines and hoses, only the front wheel brake assemblers have hoses. This is due to the need for flexibility in connecting the braking system to the moving calipers in that system. The hoses are also the weak part in the braking system due to the polymer component. It is the polymer sections of the brake lines and hoses that will crack in time causing the brake fluid to leak out. It is possible for the brake lines to have a rupture but that would require the metal tubing to rust causing a leak. This is a very rare occurrence on a Lincoln.
To identify a leaking brake line or hose, pressure must be placed on the system so the brake fluid is forced out of the rupture. This is generally a two person job with one depressing the brake pedal with the other inspecting the lines and hoses. The breach in the braking system will appear as a fountain from the pressure being applied to it.
Once the faulty brake line or hose is identified, a replacement component can be fitted to the Lincoln. Before the vehicle is returned to service, the air that entered the braking system has to be removed by a process called bleeding the brakes.