1997 Oldsmobile Achieva Owner's Manual - Page 213

How to Add Coolant to the Coolant Surge Tank If you haven't found a problem yet, but the coolant level isn't at FULL COLD, 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 you do it. (See "Engine Coolant" in the Index for more information.) A CAUTIOP Steam and scalding liquids from a hot cooling system canblow out and burn you badly. They are under pressure, and you turn the coolant if surge tank pressure cap even a little they can come out at high speed. Never turn the cap when the cooling system, including the coolant surge tank pressure cap, hot. Wait for the is cooling systemand coolant surge tank pressure cap to cool if you ever have to turn the pressure cap. -- -- 5-17