GMC 1995 Jimmy Owner's Manual page 218

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 clean water (preferably distilled) and a proper antifreeze at
the coolant recovery tank. (See "Engine Coolant" in the Index for more
information about the proper coolant mix.)
I
NOTICE:
In cold weather, water can freeze and crack the engine, radiator,
heater core and other parts. Use the recommended coolant.
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