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Discussion Starter · #1 ·
I've seen molybdate and nitrite, but at what range? I have the ability to test for very specific residuals, but does anyone know what the recommended range is? I would assume the Mo6 around 100ppm? sodium nitrite around 1,000ppm? I would think there is probably some tolytriazole in there at some amount to protect copper. pH above 8.5 for steel an below 9.5 for copper. I ordered a bottle of the VC-8 inhibitor to test it, but I am not paying $10 for 4 test strips when i can much more accurately test for inhibitor levels. Those who have the test strips, what exactly do they display when using them?
 

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Those who have the test strips, what exactly do they display when using them?
I've got them and they're in recommended SCA units per gallon. Never cared about the recommended range as long as the system was in the range shown on the strips and chart. Also never though the small price for a few strips was that much out of hand. You can probably see the chart that comes with the strips showing the ranges on the Fleetguard website.
 

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Just drain and flush the coolant system. Then replace with 4 gallons of Fleet Gard concentrate and 4 gallons of steam distilled water. Good for about 100K miles. About $70 for Fleet Gard and $5 for water.
 

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Shawn, the Fleetguard ES is good for 150,000 miles in a heavy truck so it is good just about forever in a diesel pickup. I've had the same mix without a change in my pickup for at least 18 years and for over 200,000 miles. In all that time, I've only added a cupful of ES Extender two times. Regardless of what the "expert" anti-ELC member here has preached for years about it destroying your engine seals, etc, this is direct from the Fleetguard information:
Compatible with gaskets, elastomers and other non-metallics in the engine
 

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Discussion Starter · #5 ·
Thank you, i did find the fleetgaurd chart online after i posted this, it really doesnt give much detail as to what their control ranges for the inhibitors would be.

In my line of work, i am just not a fan of test strips, too many things can cause interference with them, temperature, humidity in the packet, oils etc. We treat very large heating and cooling loops and control corrosion in them at much higher temperatures, i was just curious what was in these products, because i'm sure whatever it is we have thousands of gallons of it i could probably test and treat better for $0.15 and know it's right.

The "caviation" these engines have is most likely oxygen pitting. The failures occur on thinner areas because #1 it takes less time to corrode through that area and #2 those areas are probaly higher temperature (less material to heat up with combustion) which accelerates oxygen pitting. The sodium molybdate and sodium nitrite are both oxygen reducing agents but more importanty oxidize the heat transfer surface in a controlled manner and provide a passive magnetite layer over the metal so that there is essentially a sacrificial material over the existing metal. A sort of metal paint. Using molybdate also results in a much lower conductivity/TDS which further inhibits corrosion from electrolysis. Sodium nitrite is a very high tds corrosion inhibitor and is generally worth steering away from in place of molybdate - cost usually being the only reason sodium nitrite is worth choosing. Tolytriazole would be added to protect the copper in the brass of the radiator and oil cooler.

If it werent for the freezing risk it's better to treat systems without glycol as glycol actually inhibits fluid heat transfer efficiency.

I'll look for the fleetguard coolant and drain, then flush and refill. I also purchased a coolant filter for this truck as i feel filtration is very important to any sealed fluid system

I have also noticed the radiator in my truck looks new but the seat for the radiator cap is damaged/rough and doesnt seal properly. I attemped to smooth the surface out with JB weld so the gasket would seal but i am thinking i may need to use an o-ring to get it to seal or replace the radiator.
 

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A good radiator shop can replace just the neck, if you don't already have a plastic tank. Much cheaper than a whole radiator.
 

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metal so that there is essentially a sacrificial material over the existing metal. A sort of metal paint.
As a heavy diesel mechanic for mucho years, that's exactly the way I've always understood how SCA's work. And the pitting is caused by the cylinder wall impulses or vibrations caused during the normal diesel firing strokes reacting against the oxygen bubbles. If I remember right, the problem doesn't exist in the Cummins engines used in the Dodge pickups because there's a center web cast around the cylinder walls on the coolant side. Coolant filters were standard on the big Cummins and others not so much for filtering, but they slowly release SCA's into the system. Just my opinion, but I don't think a filter is necessary on a pickup engine as long as the proper coolant is used. I bought my truck new in '91 and have drained my system numerous times for 2 or more water pump replacements, radiator top tank repair, etc, and the coolant is always crystal clear I think mainly due to the quality of Fleetguard (owned by Cummins). I used to replace a lot of cylinder liners in the 855 cu. in. Cummins engines but it was always due to drivers not staying up on their coolant maintenance like so below:
 

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I've seen basically the same on the engines I've worked on. But it was more down in the lower sleeve area. I always thought it was due to chemical reaction, and hard water(always looked like it washed out, as opposed to erosion). Usually the o-rings/omni seals would let go, and the coolant would wind up in the crank case, then it would get a ton of Bars Leaks poured down the radiator. Once the radiator stopped working because there was no flow, then we would swap out the engine, and rebuild, only to wait for the next one to let go. This always seemed to happen to the Waukesha Natural gas fired engines. The Cats, Whites, Cummins, and Minneapolis Molines never seemed to have any problems. We never ran any SCA's. Granted most of these engines were much bigger than what is in the usual heavy truck, and probably would have had problems if they had thinner cylinder sleeves.
 

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Discussion Starter · #9 ·
Unfortunately i do have the plastic tank, i think i can get it to seal with an oring place around the neck to add tension on the washer gasket

That sleeve looks just like oxygen pitting. It finds a place and bores holes right through it. My bottle of VC8 got here today i'm going to be sure to test it before adding it to see what concentration it is. It does contain sodium molybdate and sodium nitrite.

Do you recommend doing a flush on the system with a good flush product? The antifreeze is perfectly clean - green, but looks like it was maintained. I read there are two plugs to remove from the block to drain it all. I am hoping to flush and refill then install the filter. I've seen some crazy amounts of debris filtered out on very clean systems so knowing of corrosion issues inside of these engines i will certainely be filtering the coolant.
 

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Discussion Starter · #10 ·
Well today i remembered i wanted to test this "special" glycol blend when i had my kit out. What i had was a 50/50 mix of PrimAtech Heavy Duty Antifreeze and coolant precharged with SCAs and compatible with aluminum with low silicate and distilled water. I was very surprised.

glycol concentration - 53% Ethylene (tested with refractometer)
conductivity - 1705us (pretty standard for a 50% glycol solution)
pH - 10.98 - This is EXTREMELY high for anything other than carbon steel, copper a maximum of 9.5, and aluminum generally 8.5.
Sodium nitrite - 2400ppm - higher than necessary for many hot water applications but wont hurt anything
total alkalinity - 2250ppm - typical as reserve alkalinity for glycols usually borate is used
Molybdate - 0.00ppm - very alarming considering it is listed at compatible with aluminum especially being low silicate. silicates generallly lay a deposit/scale on the aluminum to protect it.

I am really not sure how they are expecting aluminum to survice at a pH of 11 which is WAY too high even with 200+ ppm of molybdate. I didnt check for tolyltriazole to see how much would be available to tie up any copper floating around but i cant imagine an aluminum radiator lasting more than 2 years at that pH.

I am going to buy some different verisons of glycol and test them too, what are the popular brands everyone else is using? I may buy an extra bottle of the motocraft additive and test it at the correct concentration to see what it would provide. I believe i have some Fleetcharge laying around too that i filled the truck up with last after the water pump, or ill just test the cooling in the truck itself.

I am very curious to see what other SCA formulations contain becuase this is not anywhere acceptable to treat anything with aluminum. It's fine for steel, but damaging to aluminum.

 

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I appreciate your posts on the coolant issue. Keep em going!

> Molybdate - 0.00ppm - very alarming
> even with 200+ ppm of molybdate.

Aren't these two statements contradictory?

Do you suppose that with the added SCAs one could run distilled water with no glycol? The additives will lower the freezing point somewhat, won't they? I live in a mild climate. I have seen a low of 29° so far this winter. And if I never have a problem with cooling, I guess I don't need to worry about this anyway.

If you come up with a recommendation for a mix of chemicals to replace/improve on the bottled SCAs, please post up.

Are you going to lower the PH to protect... uh.. the aluminum? And where is the aluminum in there that we are concerned about? Can you suggest a test for PH available to me?

Let us know what coolant filter you purchased please.

GeoB
 

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Do you suppose that with the added SCAs one could run distilled water with no glycol? The additives will lower the freezing point somewhat, won't they?
GeoB
Not a good idea. Engine coolant does far more than prevent freezing. It is a lubricant for your waterpump, it prevents boil-over, it has corrosion inhibitors, etc..

There is a reason every car on the road has anti-freeze in it. Don't let this feller scare you.

Cheers
 

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Shawn McAdams,

Ethylene Glycol Anti-freezes typically operate in the pH range of 10.

If they were < 8.5 as you suggest for Aluminum protection then the coolant has actually degraded to the point of being corrosive.
 

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How compatible are ELCs to mixing with nitrite based old stuff left in block?
I have test strips with two sections one for old style nitrite and one for ELC. ELC only indicates appropriate protection. The Nitrite has two tests on it.
How big a deal really is it for I guess the half gallon/gallon in block.
You guys are impressive with these chemicals.
 

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As a life-long diesel mechanic, like most other truck mechanics, I take the easy route. Knowing the experts in the field that manufacture and R&D the stuff know WAY more than any of us, I poured Fleetguard ELC in years ago and went on with life. As far as draining the block, there will be 2 1/2 gallons trapped there unless the block drains are pulled on a 7.3.
 

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Yeah I did mine two years ago when reoringing injectors and was November and did not want to take the shower.
Guess I'll flush and do over in the spring.

What exactly is the interaction at that volume and effect?
 

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Discussion Starter · #19 ·
As a life-long diesel mechanic, like most other truck mechanics, I take the easy route. Knowing the experts in the field that manufacture and R&D the stuff know WAY more than any of us, I poured Fleetguard ELC in years ago and went on with life. As far as draining the block, there will be 2 1/2 gallons trapped there unless the block drains are pulled on a 7.3.
The same experts that didnt even mention or think of the possibility of oxygen pitting/caviation without corrosion inhibitors?
 

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The same experts that didnt even mention or think of the possibility of oxygen pitting/caviation without corrosion inhibitors?
Where did you come up with that idea? Fleetguard, Pencool, (Penray) and others in the heavy truck coolant industry have made products specifically to fight liner erosion since the '50's. Their products have been standard equipment in loaders, dozers, trucks, and on and on. Those would be the experts I'm referring to.
 
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