1997 GMC Sonoma Owner's Manual - Page 265

Adding Coolant If you need more coolant, add the proper DEX-COOL@ coolant mixture at the coolant recovery tank. Add coolant mixture at the recovery tank, but be careful not to spill it. rn Turning the radiator pressure cap when the engine and radiator are can allow steam and hot scalding liquids to blow out and burnyou badly. With the coolant recovery tank, you will almost never haveto add coolant at the radiator. Never turn the radiator pressure cap even a hot. little when the engine and radiator are A CAUTION: IA CAUTION: You can be burned if you spill coolant on hot engine parts. Coolant contains ethylene glycol, and itwill burn if the engine parts arehot enough. Don't spill coolant on hot engine. a I -- -- 6-27