Front wheels heating up intermittently?

Here's a few random test that may help - Jack front of truck up and have helper pump brake pedal hard with engine on - then let off pedal .. Now try to turn both front wheels .. Hard to turn? .. IF not .. It's possibly just from driving conditions that warrant more braking... IF BOTH front wheels hard to turn, possible brake booster problem... IF just one wheel hard to turn, suspect rubber - flex - brake hose *collapsed internally* on that side and holding residual pressure on brake pads.... Loosen bleeder screw, got pressure 'without' pedal applied? .. That wheel turn freely now? .. It is not unusual for the wheels to become pretty hot to the touch, even with normal braking! .. Now if truck will not roll down slight grade OR smoke is present from wheel area due to brakes holding or dragging, then that IS a problem! .. Just saying.