Loss of about half of the brake pedal, and most likely the ABS system. The part retails for $1,747.32. The problem from talking to mechanics and searching is apparently sticking valve(s) which in turn makes the brake fluid by-pass half of the system. In other words you only have the use of part of the brake system.

Our car has 170k miles but that's ~ 90% highway miles, we bought it ~6yrs ago with 15k miles, which means the brakes don't get that much use. The rear shoes were just replaced for the 1st time @ 170k and the front pads have been done once.

Ford cares so much about the lives of people driving their cars that they continue to sell the same part (Modulator Valve - Ford (9L8Z-2C346-C)) without any engineering changes/updates, even though this is a common problem across car lines and even trucks.

They have issued a recall, #19S54 for select 2006-10 Ford Fusion, Mercury Milan and Lincoln MKZ vehicles that exhibit the same issue, "a normally closed valve inside the hydraulic control unit may stick open, which could result in extended brake pedal travel, potentially increasing the risk of a crash.".

An interesting point in the recall is this: "The system will be pressure-flushed with DOT 4 brake fluid and the DOT 3 reservoir cap will be replaced with a new DOT 4 cap."

Our vehicle has a DOT3 cap, is DOT3 what causes the problem with "stuck or slow-responding valves" per recall, and DOT4 being synthetic keeps valves from sticking or becoming slow acting because of the viscosity difference between the 2?

From Amsoil "DOT 3 is the most common type used in cars and trucks today. DOT 4, however, is gaining popularity due to widespread use of anti-lock braking systems and traction control, which benefit from DOT 4 fluid’s lower viscosity."

This: "As of 2006, most cars produced in the U.S. use DOT 4 brake fluid." Except for Ford apparently, leaving owners with broken brake systems and expensive repairs.

Do they care?