1994 GMC Sonoma Owner's Manual - Page 246

Windshield Washer Fluid To Add Open the cap labeled "WASHER FLUID ONLY." Add washer fluid until the bottleis full. NOTICE: When usingconcentrated washer fluid, followthe manufacturer's instructions for adding water. Don't mix water with ready-to-use washer fluid. Water can cause the solution to freeze damage your washer fluid and tank and other parts of the washer system. Also,water doesn't cleanas well as washer fluid. Fill your washer fluid tank only 3/4 full whenit's very cold. This allows for expansion, which could damage the tank if it is completely full. Don't use radiator antifreeze in your windshield washer.It can damage your washer system and paint. Fluid Leak Check After thevehicle has been parked for awhile, inspect the surface under the vehicle for water, oil, fuel or other fluids. Water dripping from the air conditioning system after it has been usedis normal. If you notice fuel leaks or fumes,the causes should be found and corrected at once.