1993 Buick LeSabre Owner's Manual - Page 249

Windshield Washer Fluid To Add: Open the cap labeled "WASHER FLUID ONLY." Add washer fluid until the bottle is full. P4OTICE a When using follow the man adding wate 0 Don't mix wate fluid. Water can cause the solution to freeze and damage your washer fluid and other parts of the washer system. Also water doesn't clean as well as washer 0 Fill your washer fluid tank only 3/4 fu when it's very cold. This allows for expansion, which coulddamage the it is completely full. 0 Don't use radiator antifreeze in you1 windshield washer. It can damage you washer system and paint.