2007 Hummer H3 Owner's Manual - Page 344

3. Fill the radiator with the proper DEX-COOL® coolant mixture, up to the base of the filler neck. See Engine Coolant on page 335 for more information about the proper coolant mixture. 4. Fill the coolant recovery tank to the FULL COLD mark. 5. Reinstall the cap on the coolant recovery tank, but leave the radiator pressure cap off. 6. Start the engine and let it run until you can feel the upper radiator hose getting hot. Watch out for the engine cooling fan. 7. By this time, the coolant level inside the radiator filler neck might be lower. If the level is lower, add more of the proper DEX-COOL® coolant mixture through the filler neck until the level reaches the base of the filler neck. 8. Then replace the pressure cap. At any time during this procedure if coolant begins to flow out of the filler neck, reinstall the pressure cap. Be sure to secure it tightly. 344