1994 Chevrolet Astro Owner's Manual - Page 245

I NOTICE: If you use an improper coolant mix, your engine couldoverheat and be badly damaged.The repair cost wouldn't be covered by your warranty. Too much water in the mix can freezeand crack the engine, radiator, heater core and other parts. Some conditions, such as air trapped in the cooling system, can affect the coolant level in the radiator. Check the coolant level when the engine is cold and follow the steps under "Adding Coolant" for the proper way to add coolant. If you have to addcoolant more than four times a year, have yourdealer check your cooling system. I NOTICE: If you usethe proper coolant, you don't haveto add extra inhibitors or additives which claim toimprove the system. These can be harmful. Adding Coolant To Check Coolant When your engine is cold, the coolant level should be at COLD LEVEL, or a littlehigher. When your engine is warm, the level should be upto COLD LEVEL, or a little higher. 6-27