I have a 1997 super cab 2wd with the 4.6. It will idle without overheating but if driven it overheats. I noticed that top hose has pressure on it and is hot while the bottom hose is cold and this morning the top hose was sucked flat. The water pump has been changed as well as the thermostat and heater hard lines on the intake plz help

 

If you know for sure the new water pump and thermostat are good then I would check for a clogged radiator. Also, when you drain the system to check the radiator pop out the thermostat and drill a small hole in it if you didn't when you installed it.