1993 Buick Century Owner's Manual - Page 206

i k 5. Put the cap back on the coolant recovery t n , but ak leave the radiator pressure cap off. 6. Start the engine and letit run untilyou can feel the upper radiator hose getting hot. Watch out for the engine fan. 7 By this time, the coolant level inside the radiator filler . neck may be lower. If the level is lower, add more of the propermix through the filler neck until the level reaches the baseof the filler neck. 204