Fellas, I'm stumped. Yesterday, I drove to work just like I have been for the past 3 years. 10 miles. Truck drove fine. Came out after work to drive home, and truck drove fine for first few 100 yards and then I started noticing a left pull. I got out on the local highway (55mph), and the longer I drove, the harder it pulled to the left. By the time I got home, if I let go of the steering wheel, it damn near pulled me into the ditch. So, I got home, and could smell a strong odor from the front left wheel well. It was extremely hot to the touch. So, I jacked up the front left, and it was almost seized. I could move the tire, but it had no spin free play. So, I let it cool off a couple hours, pulled the wheel off, and inspected the calipers. One of the slide pins was seized, so I pulled it out, cleaned it thoroughly, applied silicon brake lubricant, and put everything back together. The seized caliper pin was the smoking gun obviously, right?!?! I drove around the neighborhood (10mph) and everything seemed fine. Well, I hop in the truck this morning, and I pull out of the neighborhood and it starts pulling hard left again. The further I go, the harder it pulls. The weird thing is, without brake applied it pulls left, but when I apply brake, it then pulls hard right. Soooooo, I'm a bit confused. Pulling left when no brakes, pulls hard right with brakes. Are the caliper pistons stuck on the front left caliper?? I replaced the hubs with Timken hubs about a year ago, so I think I can rule out bad hubs. But as it heats up, it seems like it makes the problem worse... What are your thoughts???