Badfish740

I just drove my pickup to work after sitting for about two months. I noticed it was pulling to the left and figured I had whacked it out of alignment finally. Then when I got to work I smelled brakes after I got out of the truck. I touched the left front wheel/lugnuts and they were too hot to keep my hand on for more than a second or so. The passenger side lugs were barely warm. These are relatively new (2 years old or so) T-100 calipers. I need to get the truck into good working order before a 100 mile drive to camping this weekend. What is the usual culprit? Stuck pistons? Stuck pins?