Sad to say, but I have had my share of issues with Ford calipers deciding to freeze up, eat rotors, smoke, scoot wheels, etc.
I have also known of numerous other peoples calipers doing the same, all Fords of one kind or another.
I honestly think it is a problem with Fords design.
I have old ancient Chevys and Dodges around here with the original calipers and they still function like new.
Considering the age of these trucks, it is just good business to go ahead and replace all of the brake-hoses, preferably with braided stainless.
Also, there are sliding points on the calipers that one should grease at regular intervals and not just when they are off for whatever reason.
Still again, even with good hoses and good caliper maintenance, these calipers are prone to hanging up, either just dragging or completely refusing to release.