Cooling System Cleaners (aka RMI 25)

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Burla

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A thread to post results from how your flush your cooling system with chemicals. I was astonished when I just scene a flush that uses lye, like wow man that is a bad idea? I have had RMI 25 produce slime in my overflow on older vehicles, so I know it works. It is mild and a leave in product, I have been using it in the ram for 10 years now. It also stops electrolysis damage. So here is two to start the conversation, post what you use or results with any flush. I encourage people to look up SDS because you don't want lye in your cooling system. There is another part of the Wynn's process, but man lye can damage your engine.

RMI 25 is a natural Cleaner doesn't even carry prop 65 warning sds

Wynn's Cooling System Cleaner us 50% Sodium Hydroxide aka lye per their SDS.
 
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Burla

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My buddy Google ai

Putting lye (sodium hydroxide) in a car's cooling system is extremely dangerous and should never be done; it is highly corrosive and can severely damage the cooling system components, including the radiator, hoses, and engine block, potentially leading to leaks, overheating, and even engine failure due to its caustic nature.

Why you should never use lye in a cooling system:
  • Severe Corrosion:
    Lye readily reacts with metals, causing rapid corrosion and pitting, significantly reducing the lifespan of cooling system parts.
  • Chemical Burns:
    Contact with concentrated lye can cause severe chemical burns to skin and eyes.
  • Harmful Fumes:
    When lye mixes with water in the cooling system, it releases harmful fumes that can be inhaled.

If you need to clean a cooling system:
  • Use specialized radiator flush:
    Always use commercially available radiator flush products designed specifically for cleaning car cooling systems.
  • Follow manufacturer instructions:
    Carefully follow the instructions on the flush product to ensure proper usage and dilution.
 

Grams

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Since 1970 while working as a dealer “technician”…. I learned that cooling-system chemicals are so harsh they can fail a water pump shortly thereafter.
I proved that on several vehicles and Never use anything but plain water to flush from then on. Never again a problem.
 

Wild one

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Since 1970 while working as a dealer “technician”…. I learned that cooling-system chemicals are so harsh they can fail a water pump shortly thereafter.
I proved that on several vehicles and Never use anything but plain water to flush from then on. Never again a problem.
When you say it failed,what failed on the water pump.Explain what you mean
 

White six four

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I was going to try some out this winter before I do coolant changes this spring but both my truck and work beater don't have radiator caps. I thought I read on their website that just adding it to the overflow tanks won't do much.? So my plan is to wait til I do the coolant changes then add it with the new coolant. Keep an eye on the overflow tanks after and do another coolant change after it hopefully works its magic. I don't have any heating problems in either vehicle and I'd like to keep it that way.
 
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Burla

Burla

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If you don't have a radiator cap, then your over flow should be pressurized, so yes it will work very well. It works anyway, but better in pressurized though the over flow tank. My rav 4 is the same, you can see it mix.
 
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Burla

Burla

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Main difference, you dont want to put pressurized overflow past fill mark, to allow for expansion. An over flow event under pressure would empty the coolant in a hurry. You generally don't want to over fill on any coolant, but the cooling system will run dry in a hurry if the fluid cant expand.
 

EdGs

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We use lye at my work in our manufacturing process, and it is very harsh stuff. It's also used in many cleaners including a/c coil cleaners, etc.

In fact, the buckets of sodium hydroxide that we got many years ago had a recipe to make soap on the label.

It is so harsh that even with a heavy rinse, it is very hard to get all the residue off, and has a slimy feel if you get it on your hands.

Definately not something I would recommend, in any concentration, to use in a vehicle cooling system.
 

White six four

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If you don't have a radiator cap, then your over flow should be pressurized, so yes it will work very well. It works anyway, but better in pressurized though the over flow tank. My rav 4 is the same, you can see it mix.
Nice! I just did a quick glance at their website trying to find where I read that info but I can't find where I did. So maybe I misread something before or....old age is kicking in. I'll order some and throw it in both vehicles when I get back from vacation.
 
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Burla

Burla

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So here is how Wynn's uses that lye, this process ensures it is in system for perhaps 10 minutes. If you ask me this would have to be some radical last resort method, but at least you can see Wynn's plan. The fact one product like this exists, you need to check your msds? Of note as already said, rmi-25 has nothing corrosive or toxic, the only thing listed on their SDS is a small % of dye.

 
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Burla

Burla

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Looks like the most popular ones are related to citric acid so generally safe, prestone, fleet guard, gunk. Look up SDS some contain other things such a as alcohol.

Of note zerex by Valvoline has some lye as well.
 

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When you say it failed,what failed on the water pump.Explain what you mean
I’ve had only one water pump fail with the impeller spinning on the shaft and therefore unable to push water thru the system, but have witnessed a half dozen that lost their seals and/or bearings within a week or so of the treatment with commercial cooling system treatments.
Using plain water from the garden hose has never given me that problem.

I quit working as a dealer-mechanic decades ago but do almost all my maintenance on personal and ranch equip’t and have family members who have experienced the same problem…. Have to replace the water pump shortly after using a commercial system flush product.

My personal technique is to drain the old coolant and refill the system with plain water, (bleed the air), start the engine and run it for a few minutes (don’t forget to select full HOT on the heater to clear that system) and drain again, then fill with new coolant.

There is no reason to need or introduce harsh chemicals to an intact cooling system. Ever.

If the cooling system is clogged with rust/sediment/etc…then it will need to have the engine disassembled and the heads and block “boiled out” in a vat. If you DO use harsh chemicals then before you introduce fresh coolant… Replace the water pump, thermostat, any control-valves and hoses first. That’s my personal opinon. YMMV
 
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Wild one

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I’ve had only one water pump fail with the impeller spinning on the shaft and therefore unable to push water thru the system, but have witnessed a half dozen that lost their seals and/or bearings within a week or so of the treatment with commercial cooling system treatments.
Using plain water from the garden hose has never given me that problem.

I quit working as a dealer-mechanic decades ago but do almost all my maintenance on personal and ranch equip’t and have family members who have experienced the same problem…. Have to replace the water pump shortly after using a commercial system flush product.

My personal technique is to drain the old coolant and refill the system with plain water, (bleed the air), start the engine and run it for a few minutes (don’t forget to select full HOT on the heater to clear that system) and drain again, then fill with new coolant.

There is no reason to need or introduce harsh chemicals to an intact cooling system. Ever.

If the cooling system is clogged with rust/sediment/etc…then it will need to have the engine disassembled and the heads and block “boiled out” in a vat. If you DO use harsh chemicals then before you introduce fresh coolant… Replace the water pump, thermostat, any control-valves and hoses first. That’s my personal opinon. YMMV
I've never had a water pump go south from using a chemical flush,which makes me think the water pumps you had go south,would of went south in a short period of time anyways,chemical flush or not.
Nobody is gonna pull a good running engine ,tear it down and have it hot tanked to flush rust and sediment out of the block .As soon as you hot tank it,it's gonna need new cam bearings at the very least,come on man give your head a shake
 

Grams

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I've never had a water pump go south from using a chemical flush,which makes me think the water pumps you had go south,would of went south in a short period of time anyways,chemical flush or not.
Nobody is gonna pull a good running engine ,tear it down and have it hot tanked to flush rust and sediment out of the block .As soon as you hot tank it,it's gonna need new cam bearings at the very least,come on man give your head a shake
If it had only happened once…or twice…. but I observed it many times, on customers cars as well as my own. It’s not worth it to me…. just to “clean out” imaginary sediment/rust.
IF THE COOLANT you’ve been using was good and correct…Then it will have done it’s job to prevent rust and sediment….there’s no reason to do anything more than rinse it out and replace the coolant. IMO
 

Grams

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You obviously haven't seen the sediment build up on a lot of the 4th gens with plugged heater cores have ya bud.
Correct. I don’t use incorrect coolant or keep it installed longer than called for, … If the heater core is plugged…it’s because it hasn’t been cared for properly.
 

Wild one

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Correct. I don’t use incorrect coolant or keep it installed longer than called for, … If the heater core is plugged…it’s because it hasn’t been cared for properly.
Okay you're fairly new here,so we'll have to give you a little leeway,but there's a sh!tlo@d of threads on here dealing with cooling system issues,with quite a few pics of what guys have got out of their cooling systems,and the majority of them seem to be a casting sand issue,including your Cummins. If you use the search bar up in the right hand corner,you'll find alot of the threads
 

crash68

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^^^ what @Wild one stated
If the heater core is plugged…it’s because it hasn’t been cared for properly.
There's quite a few reports of the heater cores plugging up, too many to be a lack of maintenance. Even my buddy had to have his heater core replaced in his '14 Cummins, I know he takes impeccable care of all of his vehicles.
 
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Burla

Burla

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Correct. I don’t use incorrect coolant or keep it installed longer than called for, … If the heater core is plugged…it’s because it hasn’t been cared for properly.
Learn about casting sand and egr coolers, as in egr coolers use coolant to cool them at 1500f plus. Just so your informed on it. The reason it shows up in heater cores first is that is the spot where clearances are the tightest, so they fail first or get clogged first. Indeed the heater core is usually the first sign of bad news, one ram member to the tune of 21k dollars as it took the turbo with it as well.

In theory if you use a cooling system detergent as a leave in product, it "might" help you avoid this.

.
 

MontanaHandyman

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I have had RMI 25 produce slime in my overflow on older vehicles, so I know it works. It is mild and a leave in product, I have been using it in the ram for 10 years now.

Good to know, cuz I noticed a little bit of slime in my overflow tank since adding it. I was a bit concerned.
 

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