2016 Ford Explorer- Brakes go to the floor

I took my car to ford service for my front brakes to be changed. About 3 weeks or so afterwards I went to press on my brakes and I had to press down to the floor to stop. This lasted about a day or so and then they went back to normal. My brakes work fine one minute and then the next minute I have no brakes. I have to pump the brakes and press the pedal to the floor to stop. This has happened several different times and the ford service center has no idea as to what the problem is. I’m scared to death to drive my car, because I never know if I’ll have brakes or not when I go to stop.

Take it back to Ford and insist they fix the problem, otherwise park the car. It isn’t safe to drive.

Better yet, ask Ford to come for it.

Is the vehicle still under warranty?