4.8L, 5.3L & 6.0L
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2003 GMC Savana Special, 2003 GMC Savana Camper Special, 2003 GMC Savana, 2003 Chevrolet RV Cutaway, and 2003 Chevrolet Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
Place a funnel into the upper radiator hose. Use a 50/50 mixture of DEX-COOL® antifreeze and clean, drinkable water. Slowly fill the cooling system through the upper hose with a 50/50 coolant mixture until the coolant comes out of the coolant air bleed hose. Connect the upper radiator hose to the radiator. Using the Hose Connector (J38185), position the hose clamp into the original position on the hose. Connect the coolant air bleed hose at the radiator. Fill the radiator with coolant through the filler neck. Rinse away any excess coolant from the engine and the engine compartment.