1993 Cadillac DeVille Owner's Manual - Page 255

0 Steam and scalding liquidsfrom a hot cooling systemcan blow out andburn you badly. They are under pressure, and if you turn the radiator pressure'cap even a little they can come out at high speed. Neverturn the cap when the cooling system, including theradiator pressurecap, is hot. Wait for thecooling system and radiator pressure cap to if you ever haveto turn cool the pressurecap. -- -- U.