2005 Buick LeSabre Owner's Manual - Page 272

4. After the engine cools, open the coolant air bleed valve. There is one bleed valve. It is located on the thermostat housing. 5. Fill the radiator with the proper DEX-COOL® coolant mixture, up to the base of the filler neck. See Engine Coolant on page 5-24 for more information about the proper coolant mixture. If you see a stream of coolant coming from an air bleed valve, close the valve. Otherwise, close the valve after the radiator is filled. 6. Rinse or wipe any spilled coolant from the engine and the compartment. 5-32