Ford F-150 Tenth Generation (1997-2004) No Heat Repair. In this video we install a 5/8 inch Radiator Flush Tee With Cap, Back Flush the Heater Core, Flush the Coolant System, and refill the coolant system with concentrated antifreeze and distilled water. The 5/8 inch Radiator Flush Tee With Cap is used to easily bleed the air out of the trucks heater hoses. The Back Flush the Heater Core ensures we have plenty of coolant running through the heater core to provide all the heat we need. Flushing the Coolant System to remove rust and buildup from the cooling system to gain more cooling capacity from the radiator. Refill the coolant system with concentrated antifreeze and distilled water to protect the engine from freezing and future corrosion.