Coolant - Extended Discussion - Brian

Jim Becker

Well-known Member
Brian,
In the other thread, you hit on several points I've been wrestling with. I've been using one of the floating ball testers and recently decided to throw it away and get a refractometer (although I haven't found one for $25). A year or so ago, I was moving to a considerably cooler climate so was testing coolant in everything. Some I was sure I had refilled with 50/50 mix were testing -10 or so, rather than the expected -34. My weakest mixture tested at +5, so I drained it into a couple plastic jugs. I set them outside during some of the -15 and colder weather this winter. They never froze. Also, the floating balls give no indication of too strong a mix. Using a cheap tester is just a path to wasting money on unneeded antifreeze.

I have seen multiple recommendations of the voltmeter test. Is it a useful test?

I've been trying to only buy extended life antifreeze that is labeled as compatible with all types of antifreeze. I'm not yet convinced whether such a thing exists and have yet to mix any into a Dex-Cool system. But I have been adding it to anything else. Are the "mix with anything" types really universal? Mostly I have been using Walmart's Super Tech, which is about as inexpensive as any full strength antifreeze.

Why does a Diesel have any special coolant requirements? It isn't like the fuel and coolant should ever touch each other. You mentioned wet cylinder liners. But there are plenty of wet sleeve gasoline engines out there. What is the difference?
 
(quoted from post at 20:24:16 03/07/15)
Why does a Diesel have any special coolant requirements? It isn't like the fuel and coolant should ever touch each other. You mentioned wet cylinder liners. But there are plenty of wet sleeve gasoline engines out there. What is the difference?

DCA diesel coolant additive is important for the coolant system on diesel engines. it prevents cavitation along the liners. this is more pronounced in diesels due to the type of combustion. the shock wave from ignition can cause air bubbles to form on the outside of the liners in coolant passages. those air bubbles is what causes pitting of the liners. Most newer engines have coolant filters and in that filter are the DCA tablets that release over time to protect the coolant of the engine.
 
Hello Jim!!

Attached is a link to one on eBay buy it now for
$25 with $7.50 shipping. That was just one quick
search. There may be other local sources. I know
Advance Auto has them for like $50.

Yea the floating ball testers are junk. They tell
very little about the actual freeze point of
coolant. There is a lot that can change the
reading.

As far as checking with a voltmeter...
Personally, I think that is pretty much a waste of
time. You can see stray voltage in a brand new
system and never have issues. The dissimilar
metals and the type of coolant can have an impact
on this. I have also typically found that a
cooling system has to heat cycle a few times in a
virgin system to allow the passivation of the
metals preventing this electrolysis from
occurring. In an old system like we are talking
about here, there isn't much to be concerned with.
The measurement practices and the materials used
for the actual probes can have an impact on the
readings. I wouldn't bother with it.

As for extended life coolants, caution must be
taken using the widely available ones in systems
not designed for them. Dex-Cool for example is
NOT compatible with older cooling systems designed
for traditional 2 year coolant technology. The
issue is the elastomers used in the gaskets and
seals. The formulation will attack these causing
them to shrink and harden. When the clamping
force is lost, leaks occur. It was very common in
the 90s and later for GM cars to have head and
intake manifold gasket leaks. This was the reason
for the leaks.

Whenever I have a system that has Dex-Cool in it,
I drain and flush it right away and replace the
coolant with my extended life coolant. As the
engineer that developed this technology at JD, I
can tell you that the formulation JD Cool-Gard II
is top notch. It will not have issues with older
cooling systems. I run it in all my cars and
tractors that I have rebuilt. If it is a tractor
that I haven't gone through yet, I will just keep
the freeze point in line with whatever coolant is
available easily. This is typically Zerex or
whatever. Super Tech is fine too as long as it
isn't extended life coolant...

As for the ones that say they are universal and
can be added to anything, I would tread lightly
there. This is a pretty bold statement to make by
a coolant manufacturer. There can be issues that
arise. I would try to stay away from mixing
coolants in a system you have much invested in or
care much for....

Diesel engines that have wet cylinder liners have
cavitation pitting issues on the thrust side of
the liner. This is due to the combustion
pressure, firing frequency, cooling system
pressure, sliding friction and liner to block fit.
The wall actually moves back and forth like a bell
ringing. Every time it retracts, the low pressure
zone causes cavitation bubbles to form and burst.
When they burst, it blasts away at metal on the
surface. It wasn't uncommon to see an engine
exhibit issues with coolant in the power cylinder
within the first oil change when the wrong coolant
was used at a rebuild.

To combat this, historically, nitrite was used in
HD coolants. This would get consumed quickly
during operation passivating the liner surfaces.
So a supplemental coolant additive containing
nitrite was developed. Annually this would be
added to coolant to restore the protection.
Later, manufacturers developed dosing filters that
introduced the nitrite during operation so
operators didn't need to remember to add it.

Today, organic coolant additives are used in more
advanced coolants to prevent liner cavitation.
These are in drastically higher concentration and
do not require annual maintenance to retain their
ability to protect. Many of the coolant filters
have been removed for cost reasons.

So if you want a good extended life coolant for
any cooling system, visit your local JD dealer and
buy Cool-Gard II. It comes in concentrate or pre-
mix. It will give you 6 years or 6000 hours of
operation trouble free. You can check it with the
test strips, but you will find that noting is
needed.

I hate promoting on here, but it is a good product
and there are so many out there to stay away from,
it is hard not to promote a good product.

If you have any other questions, please feel free
to ask....
Coolant Refractometer
 
Thanks for the detailed reply. Your Diesel engine explanation makes sense, as do your other comments.

This is the Walmart Super Tech I've been using:
www.walmart.com/ip/Super-Tech-Antifreeze/16645420

The MSDS that seems to apply is a Prestone MSDS. I have been using it in my tractors and my pre-Dex-Cool GM vehicles. It claims 5 years life and says "Works with all makes and models, Mixes with any color antifreeze". It is green. I have not put it in a vehicle with Dex-Cool, and won't. I think the colors are generally there for good reason and I don't want to mix them.

I'm sure Super Tech is fine in the old tractors.

The vehicles where I have trouble deciding what to use are the relatively late models with some aluminum parts but predate the use of Dex-Cool. Sounds like a trip to the John Deere dealer is the answer.
 
Jim,

I couldn't find an MSDS for the Super Tech
antifreeze online. But what I do see it that it
appears to be an extended life coolant. You should
check to see if it contains a hazardous chemical
called 2-ethylhexanoic acid. This will be listed
on the MSDS sheet. This is the element that
causes issues with gaskets and seals. I would
stay far away from any coolants containing this.

As for colors, there is no rhyme or reason for
them. Coolant manufacturers use color to
distinguish between different blends as well as
provide a color that is able to be seen in the
opaque overflow bottle. Mixing red, yellow,
orange or blue color isn't so much the issue. The
issue is mixing coolant technologies.

Engine coolant is fine balance of additives that
are intended to provide specific protection.
Playing chemist in the field is generally not
recommended. Now if it is an older tractor I
spent $800 on and want to run it, that is one
story. If I just spent $8K on a full rebuild,
that is a whole nother story.
 
I was evidently in error when I said SuperTech was made by Prestone. Looks like I should have said Peak. This seems to be the correct MSDS.
http://msds.walmartstores.com/client/document?productid=ea1f6cff-d946-4594-be15-9eb71db141ad&action=MSDS&subformat=NAM

It lists ethelene glycol, diethelene glycol and "Proprietary sterile, aqueous, isotonic solution". No specific mention of 2-ethylhexanoic acid.

I had assumed the color coding was to distinguish compatible technologies rather than being marketing ploys. I guess that would make too much sense.

I hear you on the additive balancing act. Motor oil is the same way. Dumping snake oil in with an oil change is likely to do whatever is claimed but at the expense of something else that is equally important.
 

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