1995 GMC Sonoma Owner's Manual - Page 197

NOTICE: Engine damage from running your engine without coolant isn't covered by your warranty. If there seems to be no leak, start the engine again. Seeif the Fan speed increases when idle speed is doubled by pushing the accelerator pedal down. If it doesn't, your vehicle needs service. Turn off the engine. How to Add Coolant to the Coolant Recovery Tank If you haven't found a problem yet, but the coolant level isn't at ADD, add a 50/50 mixture of clecm I . V C ~ ~ Y(preferably distilled)and a proper antifreeze at I' the coolant recovery tank. (See "Engine Coolant'' in the Index for more information about the proper coolant mix.) A CAUTION: NOTICE: In cold weather, water can freeze and crack the engine, radiator, heater core and other parts. Use the recommended coolant. 5 - 13