1995 Buick Century Owner's Manual - Page 188

3. Fill the radiator with the proper mix, up to the base of the filler neck. If you see a stream of coolant coming from an air bleed valve, close the valve. Otherwise, closethe valves after the radiator is filled. 4. Rinse or wipe any spilled coolant from the engine and compartment. 5. Then fill the coolant recovery tank to the FULL HOT mark. 5-22