2003 Ford F-150 Brake grabbing.

My father's truck was in storage for 2 years. When I retrieved it, I had the Ford dealership check it and put it in running condition. They replaced the battery, 4 worn out tires, disk brakes on all 4 wheels, changed the oil and did a front end alignment.

After driving in city stop and go traffic, I noticed a "dragging" feeling and went straight home. There was smoke coming from the right rear wheel. I sprayed water on it to cool it off and let it sit until the next morning. When I test drove, it was not grabbing.

Took it to another Ford dealership for a check up, and do do some other work. They did a brake diagnostic and could find nothing wrong. Did a major tuneup. I've driven it a number of times since then with no trouble. Yesterday, I drove in exactly the same type of stop and go, urban condidtions and the exact same thing happened. Dragging feeling, smoke coming out of right wheel, smells like brakes do when locked.

I'd appreciate your opinion before I take it back to the dealership, or another garage. Thanks!