1997 Cadillac DeVille Owner's Manual - Page 307

Adding Coolant Surge Tank Pressure Cap If you need more coolant, add the proper DEX-COOL@ coolant mixture at the surge tank, but onlywhen the engine is cool. 1 NOTICE: The surge tank cap a 15 psi (105 kPa) is pressure-type cap and must be tightly installed to prevent coolantloss and possible engine damage from overheating. sure the arrows the cap Be on line up. You can be burned if you spill coolant on hot engine parts. Coolant contains ethylene glycol, and itwill burn if'the engine parts are hot enough. Don't spill coolant on a hot engine. When replacing the pressure make sure itis tight. cap, If the surge tank pressure cap needsbe replaced, a to General Motors cap recommended. is Thermostat Engine coolant temperature is controlled a thermostat by 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 General to Motors thermostatis recommended. 6-24