1994 Cadillac DeVille Owner's Manual - Page 245

You can be burned ifyou spill coolanton hot engine parts, Coolant contains ethylene glycol and it will burn engine if the parts are hot enough.Don't spill coolanton a hot engine, 1. You can remove the radiator pressure cap when the cap and upper radiator hose are nolonger hot. 0 I I Turn the pressure cap slowly to the left until it first stops. (Don't press down whileturning the pressure cap.) If you hear a hiss, waitfor thatto stop. A hiss means there is still some pressure left. 232