2003 Chevrolet Corvette Owner's Manual - Page 260

Notice: When adding coolant, it is important that If no coolant is visible in the surge tank, add coolant as you use onlyDEX-COOL~ (silicate-free) coolant. follows: If coolant other thanDEX-COOL is added to the system, premature engine, heater core or radiator corrosion may result. In addition, the engine coolant will require change sooner at 30,000 miles (50 000 km) or 24 months, whichever occurs first. Steam and scalding liquids from a hot cooling Damage caused by the use of coolant other system can blow out and burn you badly. They than DEX-COOL@is not covered by your new vehicle warranty. are under pressure, and if you turn the coolant surge tank pressure cap-- even a little -- they How to Add Coolant to the Coolant can come out at highspeed. Never turn the Surge Tank cap when the cooling system, including the coolant surge tank pressurecap, is hot. Wait If you haven't found a problem yet, check to see if for the cooling system and coolant surge tank coolant is visible in the surge tank. If coolant is visible pressure cap to cool if you ever have to turn but the coolant level isn't at the FULL COLD mark on the the pressure cap. coolant surge tank, add a 50/50 mixture of clean, drinkable water and DEX-COOL@coolant at the coolant surge tank, but be sure the cooling system, including the coolant surge tank pressure cap, is cool before you do it. See Engine Coolant on page 5-23 for more information. 5-31