Cooling system. I have a problem with overheating.I have put in a new radiator,hoses.The head and

Question

I have a problem with overheating.I have put in a new radiator,hoses.The head and head gasket have also been changed,the engine runs hot after 20 mins or so.I can also hear coolant or some other liquid flowing while sitting in the drivers seat.Thermostat checks out,water pumps fine.