It keeps overheating despite a few repairs

It keeps overheating despite a few repairs. We removed the thermostat. Replaced the radiator cap and replaced the waterpump but it still overheats. We have not seen any hoses leaking or found any leaks anywherw. The main hoses coming from either side of the radiator, gets very hard like a pressure is built up and then we get some steam and a little water coming from under the radiator cap. Any ideas?