1998 Oldsmobile Aurora Owner's Manual - Page 235

How to Add Coolant to the Coolant Surge Tank If you haven't found a problem yet, but the coolant level 50/50 mixture of clean isn't at FULL COLD, add a 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.) Steam and scalding liquids from a hot cooling system can blow out and burnyou badly. They are under pressure, and if you turn the coolant surge tank pressure cap even a little they can comeout at high speed. Never turn the cap when the cooling system, including coolant the surge tank pressure cap, is hot. Waitfor the cooling systemand coolant surge tankpressure cap to cool if youever haveto turn the pressure cap. -- --