1998 Cadillac Seville Owner's Manual - Page 260

5. Then replace the pressure cap. Be sure the pressure cap is tight. it Start the engine and allowto warm up. If the CHECK COOLANT LEVEL message does not appear on the Driver Information Center, coolant is at the proper fill level. If a CHECK COOLANT LEVEL message does appear, repeat Steps 1 to 3 and reinstall the pressure cap or see your dealer. c' 4. With the coolant surge tank pressure cap start the off, engine and let it run until you can feel the upper radiator hose getting hot. Watch out the engine for cooling fans. By this time, the coolant level inside the coolant surge tank may lower. If the level is lower, add be the more of the proper mixture to coolant surge tank until the level reaches at above the fill mark at the or forward edge of the surge tank.