You need to install the outlet
Heater Hose, the outlet heater hose to the water pump, the outlet heater hose to the surge tank, and the outlet heater hose clamp to the surge tank, connect the heater and surge tank hoses to the heater core, pull the heater outlet hose to ensure the connection, install the heater and surge tank hoses to the mounting clip and the air intake tube and fill the cooling system.