1996 Buick Century Owner's Manual - Page 189

10. Then replace the pressure cap. At any time during this procedure if coolant begins toflow out of the fillerneck, reinstall the pressure cap. Be sure the arrows the on pressure cap line up like this. 11. Check the coolant in the recovery tank. The levelin the coolant recovery tank should be at the HOT mark when the engine is hot or at the COLD mark when the engine is cold. 8. Start the engineand let it run until you can feel the upper radiator hose getting hot.Watch out for the engine fan. 9. By this time the coolant level inside the radiator filler neck may be lower. If the level is lower, add more of the proper mix through the filler neck until the level reaches the base of the filler neck. 5-23