1997 Chevrolet Lumina Owner's Manual - Page 214
1997 Chevrolet Lumina Manual
Page 214 highlights
How to Add Coolant to the Radiator NOTICE: ~~ 2. Then keep turning the pressurecap, but now pushdown as you turn it. Remove the pressure cap. Your engine hasa specific radiator fill procedure. Failure to follow this procedurecould causeyour engine to overheat be severely damaged. and 1. You can remove the radiator pressurecap when the cooling system, including the radiator pressurecap and upper radiator hose, is no longer hot.Turn the pressure cap slowly counterclockwiseuntil it first stops. (Don't press down while turning the pressure cap.) If you hear a hiss, wait for that to stop.hiss means A there is still some pressure left. You can be burned if you spill coolant on hot engine parts. Coolant contains ethylene glycol and itwill burn if the engine parts are hot enough. Don't spill coolanton a hotengine. 5-20