The brake pedal on my 2013 suddenly went to the floor with little resistance. There was no fluid loss or warning light so I thought it was the master cylinder. I replaced it and bled the whole system in the correct manner. The peddle still goes to the floor slowly with no fluid loss and no waring light. I have talked to a couple of Ford mechanics and they have no idea.

 

Welcome, maybe the Power booster?

 

@BD Jupp We just had another member post basically the same issue. He found critters had taken a bite out of the vacuum hose for the booster. Double check your vacuum hose.

 

https://media.ford.com/content/fordm...ety-compl.html ?