96 accord 4 cylinder nonvtec never gets to opperating temp according to gauge in car, but will leak coolant out of overflow tank when temp goes to about a quarter of the way up. system seems to have exsesive pressure when running and looses all pressure out of the radiator hoses when you turn the car off. honda dealer tells me they tested the coolant system and said the block head and head gasket are holding pressure. i changed t stat, radiator and radiator hoses and still the same symptoms.