2007 GMC Sierra 1500 Pickup Owner's Manual - Page 505

Adding Coolant If you need more coolant, add the proper DEX-COOL® coolant mixture at the surge tank, but only when the engine is cool. See Cooling System on page 508. Coolant Surge Tank 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. The coolant surge tank pressure cap must be fully installed on the coolant surge tank. See Engine Compartment Overview on page 480 for more information on location. {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. When replacing the pressure cap, make sure it is hand-tight and fully seated. Engine Overheating You will find a coolant temperature gage on your vehicle's instrument panel. See Engine Coolant Temperature Gage on page 256. In addition, you will find an ENGINE OVERHEATED and a REDUCED ENGINE POWER message in the Driver Information Center (DIC) on the instrument panel. See DIC Warnings and Messages on page 270. 505