1998 GMC Suburban Owner's Manual - Page 323

Windshield Washer Fluid What to Use When you need windshield washer fluid, be sure to read the manufacturer's instructions before use. If you will be operating your vehicle in an area where the temperature may fall below freezing, use a fluid that has sufficient protection against freezing. NOTICE: 0 0 Adding Washer Fluid 0 When using concentrated washer fluid, follow the manufacturer's instructions for adding water. Don't mix water with ready-to-use washer fluid. 'Water can cause the solution to freeze and damageyour washer fluid tank and other partsof the washer system.Also, water doesn't clean well as washer fluid. as Fill your washer fluid tank only three-quarters full when it's very cold. 'This allows for expansionif freezing occurs, which could damage the tank it is if completely full. Don't use engine coolant (antifreeze)in your windshieldwasher. It can damage your washer system and paint. Open the cap labeled WASHER FLUID ONLY. Add washer fluid until the tank is full. 6-31