2001 Buick LeSabre Owner's Manual - Page 258

8. Then replace the pressure cap. At any time during this procedure if coolant begins to flow out of the filler neck, reinstall the pressure cap. Be sure the arrows on the pressure cap line up like this. 6. Start the engine and let it run until you can feel the upper radiator hose getting hot. Watch out for the engine cooling fans. 7. By this time, the coolant level inside the radiator filler neck may be lower. If the level is lower, add more of the proper DEX-COOLR coolant mixture through the filler neck until the level reaches the base of the filler neck. 5-17