Welcome Donald.
If it isn’t the brakes, there are solenoid valves in the trans that can give problems.
There is a known problem with the 5R55N and other variants of this trans at high mileage. There are two servos on the right hand side with steel shafts, which fit into holes in the aluminum case. The steel gradually wears the aluminum hole a bit oversize.
The Ford approved fix is to ream them out and install steel sleeves.
An entrepreneur in Wisconsin has come up with an alternate, which I installed. I wrote it up here:
