I went through the booster, master cylinder and HCU. Really pisses me off that Ford never developed test methods to check these items in place. They go from least expensive to most on changing parts instead. Mine started with brakes going to the floor. Ford changed the booster (recall extended warranty) and brakes were semi locked on when I picked it up. I think the three block round trip back warped my rotors, but that’s another story. They did something and all seemed good for a few days. Then back to the brakes to the floor. They (Ford) went for the master cylinder next saying it could be it or HCU. When asked about test procedures to isolate issue I got a not any! That’s pitiful for a system that’s this expensive and number of units out there. Master cylinder did not work, HCU was next! Still did not work correct! I read an article a mechanic had found adjusting the booster gap took care of a similar problem. Told the garage, they tried it and it has worked ever since. Still cost me over $2200 that’s with a free recalled booster!
