2005 Buick Century Owner's Manual - Page 242

4. Fill the radiator with the proper DEX-COOL® coolant mixture, up to the base of the filler neck. See Engine Coolant on page 5-22 for more information about the proper coolant mixture. If a stream of coolant is coming from an air bleed valve, close the valve. Otherwise, close the valves after the radiator is filled. 5. Rinse or wipe any spilled coolant from the engine and the compartment. 6. Then fill the coolant recovery tank to the COLD mark on the coolant recovery tank. 7. Put the cap back on the coolant recovery tank, but leave the radiator pressure cap off. 5-32