1998 Cadillac Seville Owner's Manual - Page 300

Adding Coolant Surge Tank Pressure Cap If you need more coolant, add proper DEX-COOL@ the coolant mixtureat the surge tank, but only whenthe engine is cool. I NOTICE: I The surge tank cap is a 15 psi (105 kPa) pressure-type cap and must be tightly installed to prevent coolant loss and possible engine damage from overheating.Two and one-half turns are required to seal the cap. IA CAUTION: You can beburned if you spill coolant on hot engine parts. Coolant contains ethylene glycol, and it will burn if the engineparts arehot a enough. Don't spill coolant onhot engine. ~~ If the surge tank pressure cap needs to be replaced, a GM cap is recommended. When replacing the surge tank pressure make sure cap, it is tight. Thermostat Engine coolant temperature controlled by a thermostat is in the engine coolant system. The thermostat stops the flow of coolant through the radiator until the coolant reaches a preset temperature. If your thermostat needs be replaced,a GM to thermostat is recommended. 6-25