2012 GMC Canyon Owner's Manual - Page 258

10-22 Vehicle Care WARNING (Continued) cooling system and surge tank pressure cap to cool if you ever have to turn the pressure cap. If coolant is needed, add the proper mixture directly to the radiator, but be sure the cooling system is cool before this is done. 2. Keep turning the cap to remove it. 3. Fill the radiator with the proper DEX‐COOL coolant mixture, up to the base of the filler neck. See Engine Coolant on page 10‑19 for more information about the proper coolant mixture. How to Add Coolant to the Radiator { WARNING An electric engine cooling fan under the hood can start up even when the engine is not running and can cause injury. Keep hands, clothing, and tools away from any underhood electric fan. { WARNING Steam and scalding liquids from a hot cooling system can blow out and burn you badly. They are under pressure, and if you turn the surge tank pressure cap - even a little - they can come out at high speed. Never turn the cap when the cooling system, including the surge tank pressure cap, is hot. Wait for the (Continued) 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 a hiss is heard, wait for that to stop. A hiss means there is still some pressure left. 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.