1998 Cadillac Catera Owner's Manual - Page 231

How to Add Coolant to theCoolant Surge Tank If you haven't found a problem yet, but the coolant level isn't at theKALT/COLD line (seam), add a 50/50 mixture of clean water (preferably distilled) and DEX-COOL@coolant at the coolant surge tank, but be sure the cooling system, including the coolant surge tank pressure cap,is cool before youdo it. (See "Engine Coolant" in the Index more information.) for 'A I CAUTION: Steam and scalding liquids from a cooling hot system can blow out and burn you badly. They are under pressure, andyou turn the coolant if surge tank pressure cap even a little they can come out athigh speed. Never turn the cap when the cooling system, including the coolant surge tank pressure cap,hot. Wait is for thecooling system and coolant surge tank pressure cap to cool if you ever have to turn the pressure cap. -- -- 5-16