1994 GMC Jimmy Owner's Manual - Page 215

The coolant level should be at above theADD mark. If it isn't, you may or have a leak in the radiator hoses, heater hoses, radiator, water or pump somewhere else in the cooling system. NOTICE: Engine damage from running your engine without coolant isn't covered by your warranty. If there seems to be no leak, startthe engine again. See if the fan speed increases whenidle speed isdoubled by pushing the accelerator pedal down. If it doesn't, your vehicle needs service. Turn the engine. off How to Add Coolant to the Coolant Recovery Tank If you haven'tfound a problem yet, but the coolant level isn't at or above the ADD mark, add a 50/50 mixture of clean water (preferably distilled) and a proper antifreeze at the coolant recovery tank. "Engine Coolant" (See in the Index for more informationabout the proper coolant mix.) 5-13