2011 Chevrolet Express 1500 Cargo Owner's Manual - Page 291

Vehicle Care Notice: If extra inhibitors and/or additives are used in the vehicle cooling system, the vehicle could be damaged. Use only the proper mixture of the engine coolant listed in this manual for the cooling system. See Recommended Fluids and Lubricants on page 11‑8 for more information. Never dispose of engine coolant by putting it in the trash, pouring it on the ground, or into sewers, streams, or bodies of water. Have the coolant changed by an authorized service center, familiar with legal requirements regarding used coolant disposal. This will help protect the environment and your health. 10-21 Checking Coolant The vehicle must be on a level surface when checking the coolant level. Check to see if coolant is visible in the coolant recovery tank. If the coolant inside the coolant recovery tank is boiling, do not do anything else until it cools down. If coolant is visible but the coolant level is not at or above the COLD FILL mark, add a 50/50 mixture of clean, drinkable water and DEX-COOL coolant at the coolant recovery tank, but be sure the cooling system is cool before this is done. The coolant recovery tank cap has this symbol on it. When the engine is cold, the coolant level should be at or above the COLD FILL mark. If it is not, there could be a leak in the cooling system. If the coolant is low, add the coolant or take the vehicle to a dealer for service.