2005 Chevrolet Tahoe Owner's Manual - Page 399

{CAUTION: An electric fan under the hood can start up and injure you even when the engine is not running. Keep hands, clothing and tools away from any underhood electric fan. If the coolant inside the coolant surge tank is boiling, do not do anything else until it cools down. The vehicle should be parked on a level surface. The coolant level should be at or above the FULL COLD mark. If it is not, you may have a leak at the pressure cap or in the radiator hoses, heater hoses, radiator, water pump or somewhere else in the cooling system. {CAUTION: Heater and radiator hoses, and other engine parts, can be very hot. Do not touch them. If you do, you can be burned. Do not run the engine if there is a leak. If you run the engine, it could lose all coolant. That could cause an engine fire, and you could be burned. Get any leak fixed before you drive the vehicle. If there seems to be no leak and your vehicle is equipped with an electric engine cooling fan, with the engine on check to see if the cooling fan is running. If it is not, your vehicle needs service. Turn off the engine. 5-33