This topic came to mind as I sat in a dock last week and smelled that familiar smell of leaking coolant we all fear.  Hoping it was not me, I investigated further to thankfully find out it wasn’t my truck, but was actually the truck in a dock next to me.  Always one to offer a helping hand and carry spare fluids, I asked him if he knew of the leak, or was in need of some extra coolant.  He let me know he had just been topping it off with water daily until he could get home to get it taken care of properly.  It was then that I cautioned him against using water to top off his coolant tank, as it could actually be working against him and may actually do things to hurt his engine instead.

In most cooling systems, exact specifications have been engineered into the coolant itself, to do much more than just cool the engine and protect against freezing.  There are optimum levels of pH acidity, anti-corrosion, anti-freezing and cooling chemicals built into all brands of coolants.  These exact mixtures far surpass the cooling and anti-freeze power of plain water alone, as water tends to boil, freeze, evaporate, and corrode under extreme conditions that are often seen in an engine’s normal operating conditions.  Adding water to specifically designed coolants that are already at these desired levels (ELC’s and EG’s alike) will not only dilute their cooling properties, but will also add other chemicals that can hurt your engine and cooling system.  Remember, the chemicals in the water don’t magically disappear once mixed in and can lead to premature corrosion and build up from inside!  Certain elements exist in tap water like salt, calcium and chlorine to name a few, that can do more damage than good.
Upon receiving my advice, this driver said he was going to head to a local truck maintenance facility I referred to get the leak fixed properly and flush his system with the proper coolant, which I hoped he followed through on for his sake.  Needless to say, I was glad to have helped educate him on the harmful effects of water in his engine’s cooling system and prevent him from making a harmful, yet common mistake.  Be sure to check for leaks, maintain proper fill levels, and maintain a proper chemical balance in your cooling system. 
Having your coolant tested is fairly inexpensive and can usually be done when your truck is in for an oil change or other basic PM service.  This can help insure that you have the proper balance of chemicals and proper pH acidity for optimum performance.  Many drivers I know use oil analysis to keep the pulse on their engine’s performance and prevent minor problems from turning into major ones, but many drivers tend to overlook the other importance of coolant tests as well until it is too late!

Comments (2)

Jimmy Nevarez

Jimmy Nevarez is the Owner/President of Angus Transportation, Inc., based in Chino, California.  Jimmy pulls a 53' dry van hauling general dry freight for his own small fleet, operating on its own authority throughout all of Southern California and Southern Nevada.

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Most definitely true Kurt. As a matter of fact, it was just a couple years ago I caught a friend who parked where I did at the time just using whatever color coolant he found to top off his leak from a weeping water pump. After I cautioned him against it and informed him of the dangerous mix he was creating in his calling system, he drained and flushed as well. Thank you for the comment!

July 10, 2016 19:34:48 PM

And if a leak is discovered, topping off with the wrong antifreeze is just as bad or worse than using just water. Resulting in the need for a complete system flush, as incompatible types will cause problems.

July 07, 2016 17:59:21 PM