1998 Cadillac Catera Owner's Manual - Page 234

3. Then fill the coolant surge tank with the proper mixture, up to theKALTKOLD line (seam). 4. With the coolant surge tank pressure cap off, start the engine and let it run until you can feel the upper radiator hose getting hot. Watch for the engine out cooling fans. By this time, the coolant level inside the coolant surge tank may lower. If the level is lower, add be more of the proper mixture to coolant surge tank the until the level reaches the KALTKOLD line (seam).