1995 GMC Yukon Owner's Manual - Page 261

7. Then fill the coolant surge tank with the proper mix, up to the COLD mark. 8. With the coolant surge tank pressure cap start the engine and let it off, run until you can feel the upper radiator hose getting Watch out for hot. the engine fan(s). By this time, the coolant level inside the coolant surge may be tank lower, add moreof the propermix to the coolant lower. If the level is COLD mark. surge tank until the level reaches the 5-23