Why does my 2000 Lincoln LS still overheat after changing the radiator and thermostat and housing

What is your question?

I put a new radiator I put a new thermostat I mechanic put a new thermostat housing and still the Lincoln overheats? The water pump sounds fine there's no water leaking out of it or anyting I believe I accurately bleed the system but I really am not sure. When it did overheat it leak coolant from somewhere I cannot find a Trace this is my mother's car as she doesn't know where the coolant was coming from either