My truck told me what it wants me to fix next

[Walts_restoration]

Turns out the correct answer was brakes. For the last couple of days ive been driving home, truck has been pulling to the right. Yesterday, she got a little topsy turvy, but nothing bad. Today on the way to my buddies it felt like the wind was going a hundred miles an hour, turns out the wind was blowing pretty good at my side, so i ignored it, then my steering got loose one way and tight the other, so i thought maybe my tie rods were going bad. When i got to my buddies house, grabbed the flashlight, crawled underneath, and was greeted with smoke. First thing i do, pop the hood, coming from drivers side, looked for wires against exhaust manifolds, nothing. Start looking some more. Driver side caliper, hubcap was extremely warm, so i now at least have located the problem. As i stated earlier, the truck was pulling to the drivers side, and the entire way home it was bucking like a bent disc, which is more than likely made itself present. I assume the caliper failed, i cant remmber if i replaced the brake lines two years ago or not, that may be the culprit, and i know my rear brakes are crap, been meaning to change them for a while. So whats everyone's vote, going to pull it off tomorrow and see. Is is possible the caliper failed and bent the disc? I wouldn't think the wheel bearings failed, because that would have locked up the front drivers wheel completely, but hen again i cannot recall if i repacked them, or they looked good enough the last time i did brakes, which was two or three years ago. Theres nothing worse than the smell of burning pads.