I have a 2004 F150 ext cab 4x4 with 106,000 miles. Saturday I was driving and I started to get a bad shimmy in the steering wheel. I could smell that the right front brake was hot! also the hub was so hot you didnt dare touch it! I was near a boat launch and drive the front into the lake and cooled everything down. If the caliper was stuck wouldnt it be pulling to the right? all it was doinf was shaking the steering wheel. I drove it home after cooling it down, anouther 30 miles and everything was fine. Sunday it was fine for 20 miles then it did it again....close to home this time..I let it cool down.jacked it up everything turned normally..tried removing the caliper but it was like welded to the back pad? I eneded up chipping both cylinders on the rotor...I am replacing the caliper tonight, bit am not sure if thats what it was??
I would go ahead and replace or have the rotor turned if the hub was too hot to touch then the rotor was probably glowing and when you drove it into the water it eather put tiny cracks in the rotor and definatly warped it.
I had a similar thing happen. The rubber seal around the caliper pistons failed and let the caliper rust. The rust flaked off and got wedged between the caliper and the pistons. Got hot enough to melt the plastic dog bowl hubcap off the wheel.
When backing my boat into the water, I usually let the wheels cool off for a few minutes while I'm getting everything ready for a day on the water. When you back a hot hub into the water, it can cool off too fast and suck water thru the seals if they are weak. (More true on the older vehicles I suppose). For this reason I usually pull my boat trailer wheels and clean and repack with marine grease once a season.