Radiator and Heater Hoses

The upper and lower radiator hoses connect the radiator to the engine. Cooled coolant is transferred from the radiator to the engine through the lower hose. Hot coolant is returned to the radiator by the upper hose. The upper hose connects to the water outlet that covers the thermostat. The lower hose connects to the water pump. Note: Some vehicles have a reverse-flow cooling system. Heater hoses are also used to transport heated coolant to the heater core that provides heat for the passenger compartment.