1997 Buick Century Owner's Manual - Page 249

4. Fill the radiator with the proper DEX-COOL@ coolant mixture, up to the base of the filler neck. If you see a streamof coolant comingfrom an air bleed valve, close the valve. Otherwise, closethe valves afterthe radiator is filled. 6. Then fill the coolant recovery tank to the COLD mark on the overflow hose in the coolant bottle. 5. Rinse or wipe any spilled coolant from the engine and the compartment. 7. Put the cap back on the coolant recovery tank, but leave the radiator pressure capoff. 5-23