1996 Buick Skylark Owner's Manual - Page 252

Adding Washer Fluid NOTICE: 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 damage your washer fluid tank and other partsof the washer system. Also, water doesn't clean as well as washer fluid. Fill your washer fluidtank only 3/4 full when it's very cold. This allows for expansion, which could damage thetank if it is completely full. Don't use radiator antifreeze in your windshield washer. It can damage your washer system and paint. Open thecap labeled WASHER FLUID ONLY. Add is washer fluid until the tankfull. 6-25