2010 GMC Canyon Extended Cab Owner's Manual - Page 309

If coolant is needed, add the proper mixture directly to the radiator, but be sure the cooling system is cool before this is done. 3. Fill the radiator with the proper DEX-COOL® coolant mixture, up to the base of the filler neck. See Engine Coolant on page 6-29 for more information about the proper coolant mixture. 1. Remove the radiator pressure cap when the cooling system, including the upper radiator hose, is no longer hot. Turn the pressure cap slowly counterclockwise about one full turn. If you hear a hiss, wait for that to stop. A hiss means there is still some pressure left. 2. Keep turning the cap to remove it. 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. 6-33