1994 GMC Suburban Owner's Manual - Page 288

Hydro-Boost Brake System (Hydraulic Pump) The power steering pump is also used as the Hydro-boost pump. Refer to "Power Steering System" in thissection when checking fluid levelor adding fluid. Windshield Washer Fluid To Add Open the cap labeled "WASHER FLUID ONLY" Add washer fluid until the bottle is full. NOTICE: When using concentrated washer fluid, followthe manufacturer's instructions for adding water. Don't miri water with ready-twuse washer fluid. Water can cause the solution to freeze and damage your washer fluid tank andother parts of the washer system. Also,water doesn't cleanas well as washer fluid. 0 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 systemand paint. 0