1995 GMC Yukon Owner's Manual - Page 255

6. Start the engine and let it until run you can feel the upper radiator hose gettinghot. Watch out for the engine fan( . s) 7. By this time the coolant level inside the radiator filler neck be may lower. If the level is lower, add moreof the propermix through the filler neck until the level reaches the base filler neck. of the 8. Then replace the pressure cap. any time during this procedure At if coolant begins to flow out the filler neck, reinstall the pressure cap. of Be sure thearrows on the pressure cap line like this. up 5-17