I just bought a 2002 F150 4x4 last week. I wanted to immediately change the brakes before I started driving too much. I had a horrible time breaking loose the rotors on the front. I read several postings on this topic, and ended up trying something else out that I don't know if anyone else has tried. 4 hours of banging and spraying pentrating catalyst on drivers side, and 5 minutes on the passenger side after using my 16 oz hammer another way.

There is obviously very little room to hammer from inside the wheel well. I took a small metal 16 oz claw hammer, and tapped the claws in the vented area between two brake surface edges. This allowed me to push down on the hamer handle and apply significant outward force to the rotor, while at the same time hitting the outer edge of the rotor with another 20 oz masonry flat faced hammer. I only hit the rotor four times and it immediately broke loose. Hope this might help only one person from spending the 4 plus hours of loud ringing of my ears and several negative verbal gestures to my new truck.