1998 Cadillac DeVille Owner's Manual - Page 270

~- ~~ ~ get the overheat warning. Your engine could catch fire and or otherscould be burned. you Use a 50/50 mixture of clean water and DEX-COOL@coolant. I NOTICE: In cold weather, water can freeze and crack the engine, radiator, heater core and other parts. So use the recommended coolant. 1. You can remove the coolant surge tank pressure cap when the cooling system, including the coolant surge tank pressure cap and upper radiator hose, is no longer hot.Turn the pressure cap slowly counterclockwise until it first stops. (Don't press down while turning the pressure cap.) You can be burned if you spill coolant on hot engine parts. Coolant contains ethylene glycol and it will burn if the engine parts are hot enough. Don't spill coolant on hot engine. a If you hear a hiss, wait that to stop.A hiss means for there is still some pressure left. 5-21