1996 Ford Aerostar Owner's Manual - Page 264

Adding Engine Coolant Adding engine coolant to reservoir RWARNING Be careful not to add engine coolant to the windshield washer fluid reservoir. If sprayed on the windshield, engine coolant could make it difficult to see through the windshield. When the engine is cool, add a 50/50 mixture of engine coolant and water to the engine coolant recovery reservoir - DO NOT ADD DIRECTLY TO THE RADIATOR. Add straight water only in an emergency, but you should replace it with a 50/50 mixture of coolant and distilled water as soon as possible. Check the coolant level in the coolant recovery reservoir the next few times you drive the vehicle. If necessary, add enough of a 50/50 mixture of coolant and water to bring the liquid level to the fill line on the reservoir. RWARNING Never remove the coolant recovery cap while the engine is running or hot. 286