2004 GMC Canyon Owner's Manual - Page 292

Add coolant mixture at the recovery tank, but be careful not to spill it. Engine Overheating You will find a coolant temperature gage on your vehicle's instrument panel. See Engine Coolant Temperature Gage on page 3-30. Your air conditioning may stop working if your engine is too hot. This is normal and helps cool the engine. {CAUTION: You can be burned if you spill coolant on hot engine parts. Coolant contains ethylene glycol, and it will burn if the engine parts are hot enough. Do not spill coolant on a hot engine. Occasionally check the coolant level in the radiator. For information on how to add coolant to the radiator, see Cooling System on page 5-30. If Steam Is Coming From Your Engine Radiator Pressure Cap Notice: If the pressure cap is not tightly installed, coolant loss and possible engine damage may occur. Be sure the cap is properly and tightly secured. 5-28