The heart and soul of your braking system is the Lincoln Brake Master Cylinder. The brake master cylinder is the component on your Lincoln that converts mechanical movement to hydraulic pressure so it can be applied to stop your vehicle's forward progress.
Inside of the brake master cylinder are two reservoirs. The front one is smaller and is for the rear braking system. The larger rear one is for the front braking system. The reason for the size difference is so the brake bias can be used which applies nearly twice the force to the front brakes as it does to the rear.
In the bottom of the reservoirs of the Lincoln brake master cylinder is a piston. This piston is activated when the driver of the Lincoln depressed the brake pedal. As the piston moves forward in the master cylinder, the brake fluid is pressurized creating the force to move the brake shoes and pads against the drums and discs so friction is created slowing the vehicle down. To make sure the brake fluid remains pressurized, there are polymer seals on the piston. It is the failing of these seals that cause a brake master cylinder to become nonfunctional.
Unlike the other braking component on your Lincoln, when the master cylinder fails, there is no exterior leaking of brake fluid that can be seen. The driver will notice that the brake pedal can move all the way to the floor when pressure is being applied to it without the ability of the vehicle to slow down. This occurs because the brake fluid is not remaining pressurized and is leaking back into the reservoir. The only solution for this predicament is the replacement of the brake master cylinder.