What would cause only one tire rim to get too hot to touch after changing brake pads?

The piston in the caliper sounds like it%26#039;s not retracting fully,lift the car up and start it,apply brakes,then see if you can turn the tire by hand,if you cant then thats the probelm.|||Improper adjustment, could be put together wrong...|||Caliper may not be sliding on the sliding bolts.Did you replace all hardware properly,to allow it to slide.If the piston went in hard then it is the caliper that needs replaced.|||Wheel bearings. Warped rotor. Improper fit / alignment. Caliper stuck.|||You%26#039;re about to have to buy a new caliper. It%26#039;s dried up, no grease. Better to go ahead and buy both. You will have to bleed the brake system after you replace the calipers because air will get into your brake lines. I actually had the brakes catch on fire when my calipers locked up on my old Thunderbird. So, replace them ASAP.|||caliper frozen it try to gt back into original position it was before you changed padsit sqeezing it too hard and it will catch fire if you dont change it;so get it done|||Shoes are probably adjusted to tight.|||Either a bad caliper or a restricted brake hose. to test it. jack up the car, apply the brakes several times. At the wheel that is dragging open the bleeder on the caliper. If the wheel still drags it%26#039;s the caliper, if it releases, it%26#039;s the hoses. NOTE. which ever it is, replace both sides or a brake pull could develop|||Distorted or damaged rotor or possible sticking caliper|||Problem. The brake pad is rubbing on the disk. Better get it checked immediately. I had a problem like this when the master cylinder went berserk and the brakes started locking up. My wheels got so hot the valve caps were melting right off the valve stems.