1998 Cadillac Seville Owner's Manual - Page 259

1. You can remove the coolant surge tank pressure cap 3. Then fill the coolant surge tank with the proper when the cooling system, including the coolant surge fill mixture, up to or above the mark at the forward tank pressure cap and upper radiator hose, is no edge of the surge tank. longer hot. Turn the pressure cap slowly about one-quarter turn to the left and then stop. If you hear a hiss, wait that to stop. hiss means for A there is still some pressure left. 2. Then keep turning the pressure cap slowly, and remove it. 5-22