Cooling system cleanliness

Rickyd said:
Unless I'm reading you wrong step one was drain thermocure then flush then

". Fill with tap water, run 10 minutes, drain, 5x. Last bucket was clear enough. One of these times tried draining through lower rad hose to make it faster and soaked my hand in 160° water, went back to using the radiator draincock.
8. Fill with distilled water, run 10 minutes, drain, 3x."

So 10min x5 and 10 min x3. Plus whatever time steps 2- et cetera took?

When i have chemically removed rust from steel before it rusts within minutes. Especially if not neutralized and dried immediately.
Click to expand...

Right. It took several hours. I don't know the right alternative. Either skip the flushes and send it with 75% new coolant and 25% thermocure and dissolved/suspended rust debris, or to do all the flush steps with some antifreeze in each one and end up with 15 gallons of diluted ethylene glycol that I can't just dump down the gutter. Or maybe there's something that would act as a rust preventer that is environmentally friendly and not terribly expensive.

At this point I'm gonna have to roll with it anyway but if I can further the forum general knowledge than I'll submit my experience. The process I followed was verbatim the WTJF cooling system flush process, so if that's leaving everybody's system just as rusty as it started then I'd like to help figure out how it can be improved.
 
  • Like
Reactions: Rickyd
freedom_in_4low said:
Looking back at this photo from before the second thermocure makes me wish I'd have just buttoned it up at that point and moved on, cause somehow it's worse now than it was. The only difference is that this one I opened up stone cold after sitting for days with distilled water, instead of opening it up still hot.
Click to expand...

After chemical treatments and about 30 tap water flushes, 8 distilled flushes, I was still getting weird yellow sulfury looking flakes out and the water turning cloudy after a drive then flush.

I was convinced draining the block would help. I pulled the drain plug, which promptly disappeared. Wife was gone so I couldn't leave the kids at the house to go search for a new one. I ended up pulling the skid plate, front DS, down tube and cats looking for it like a freakin moron. Didn't find it. Had a clear look into the block, which showed yellow fuzzy looking bullshit clinging to the inside, and enough of it that another tap water flush wasn't gonna help.

Got a new plug from ACE when my wife got home, put the jeep back together, reinstalled thermostat, filled with coolant and said maybe next year. MFs gonna need a rebuild in the next year anyway. Spent all day accomplishing nothing.

Fired up the Jeep and immediately got a new O2 sensor code then cleaned up the garage and found the drain plug under my shop table 40 feet from where I pulled it. Shaking my head.
 
  • Like
  • USA Proud
  • Haha
Reactions: hear, Bootheel Boy and sab
Bigmac said:
After chemical treatments and about 30 tap water flushes, 8 distilled flushes, I was still getting weird yellow sulfury looking flakes out and the water turning cloudy after a drive then flush.

I was convinced draining the block would help. I pulled the drain plug, which promptly disappeared. Wife was gone so I couldn't leave the kids at the house to go search for a new one. I ended up pulling the skid plate, front DS, down tube and cats looking for it like a freakin moron. Didn't find it. Had a clear look into the block, which showed yellow fuzzy looking bullshit clinging to the inside, and enough of it that another tap water flush wasn't gonna help.

Got a new plug from ACE when my wife got home, put the jeep back together, reinstalled thermostat, filled with coolant and said maybe next year. MFs gonna need a rebuild in the next year anyway. Spent all day accomplishing nothing.

Fired up the Jeep and immediately got a new O2 sensor code then cleaned up the garage and found the drain plug under my shop table 40 feet from where I pulled it. Shaking my head.
Click to expand...

yep. I think I'm convinced that there is a problem with the iron drying between flushes. I don't think it does it when cold, but when it's been running for 10 minutes and you immediately drain it, the surface is hot and any water that hangs on quickly evaporates and causes flash rust. I'm not sure if it happens on every drain/fill cycle or just the ones that take a little extra time (such as removing the thermostat housing to install a thermostat), but there are two approaches to keeping the surface wetted (and only one of them really has any chance at practicality)
  • Lengthen the time it takes for the water to evaporate by only draining when engine is cool
    • entire process becomes completely impractical if we do 8+ flushes waiting 4+hours for each one. Maybe skip the tap water process and go distilled only so you're ready for coolant as soon as you're satisfied with the clarity. That cuts out 3 flushes but is still going to take days only being able to do 2, maybe 3 flushes per day. Maybe that's not so bad though, at least it's spread out to about 30 minute spurts separated by times you can do something else, instead of going at it straight for an entire afternoon/evening.
  • add something to each flush cycle that hangs on to the metal and provides a protective barrier when the coolant is drained.
    • what to use?
      • Antifreeze creates a hazardous waste disposal problem. Some counties and municipalities offer this to residents, some don't. Even those that do may have volume limits per resident and I expect 12+ gallons is gonna push it.
      • Would need to be clear so as not to taint the "is it clear in a white bucket" test
      • would need to be environmentally friendly so that it can be dumped outside, or else we're back to the antifreeze (ethylene glycol) problem.
      • I've seen "water soluble oil" mentioned here ( @JPHikr ) but when I search it all I seem to come up with is machine cutting/cooling oils so I'm not sure if that's the right thing or if there is an automotive-cooling-specific product I should be looking for. Sounds like it only takes half a cup in the system, would it be safe and affordable to use in this way?
 
Last edited:
P man said:
My question is when is good enough? Freedom has already done way more than 90 percent of jeepers. If it were me I would wrap things up and move forward. Good job on the documentation
Click to expand...

I've definitely done way more...but until I've accomplished what I set out to accomplish, or at least have the impression that the system is cleaner than it was when I started, then it just feels like I did a whole bunch of the wrong things.
 
Mine was flushed with a couple gallons of distilled, filled with fresh coolant, and off I went
6B022A44-2B0A-488B-B5A3-C83EB538FDCA.jpeg
 
  • Like
Reactions: freedom_in_4low
freedom_in_4low said:
I don't know the right alternative. Either skip the flushes and send it with 75% new coolant and 25% thermocure and dissolved/suspended rust debris, or to do all the flush steps with some antifreeze in each one and end up with 15 gallons of diluted ethylene glycol that I can't just dump down the gutter.
Click to expand...

Do you have trash/recycling centers in your area? We have several here throughout the county that accept the usual trash, glass. metal, cardboard, oil, tires, etc. There is one that will take antifreeze.
 
MountaineerTom said:
Do you have trash/recycling centers in your area? We have several here throughout the county that accept the usual trash, glass. metal, cardboard, oil, tires, etc. There is one that will take antifreeze.
Click to expand...

I do but I haven't been able to determine yet whether they take antifreeze. My county in Colorado Springs made it really easy and it was clear on the website. Here not so much.
 
  • Like
Reactions: MountaineerTom
"I think I'm convinced that there is a problem with the iron drying between flushes"

This is why you should use water soluble oil. It gets in to the pores of the block and coats the surface, you will not see the surface rust when drying be between flushes.
 
  • Like
Reactions: freedom_in_4low
JPHikr said:
"I think I'm convinced that there is a problem with the iron drying between flushes"

This is why you should use water soluble oil. It gets in to the pores of the block and coats the surface, you will not see the surface rust when drying be between flushes.
Click to expand...

do you have a link to this stuff? A google search seems to mostly bring up machining cutting fluids. Not sure if that's by design or if I should be looking for an automotive specific product.
 
mrblaine said:
After the drive around flush with Prestone for a couple of days, then we do the Thermocure. If you leave that in too long, the black is harder to flush out. After a day or so, maybe two, then we pull the thermostat and put the housing back on. We start by filling with tap water and starting the engine to circulate that for 10 minutes roughly. We keep doing that until the drained water is clean and clear into a clean white or light colored bucket. When it is clean, then we do two full flushes with distilled. Drain that, install new thermostat that has a 1/8" hole drilled next to the jiggler. Fill with coolant pre-mix of 1/3 distilled to 2/3 coolant. Start and circulate until we see the coolant movement in the radiator that shows the thermostat has opened, install radiator cap, top off overflow reservoir to the full level.

We have never pulled the block drain and never will.
Click to expand...

When you do the Prestone treatment, how do you do it? Do you just leave the coolant in there? Do you drain the coolant and fill with Prestone plus tap water, or Prestone plus distilled water?
 
Gonna be rinsing and possibly flushing out my cooling system using BlueDevil rad cleaner (if it looks like it needs it behind the tstat).
Using distilled water for all of my flushes would certainly be ideal but at $3/4L jug it’s not exactly cheap here.
I see @mrblaine uses tap water for initial flushes. I’m not on city water, my tap water goes through a softener and 3-stage filter (NOT reverse osmosis).
Would I be okay to use this water for initial flushes then 2-3 flushes with distilled?
 
James9100 said:
Gonna be rinsing and possibly flushing out my cooling system using BlueDevil rad cleaner (if it looks like it needs it behind the tstat).
Using distilled water for all of my flushes would certainly be ideal but at $3/4L jug it’s not exactly cheap here.
I see @mrblaine uses tap water for initial flushes. I’m not on city water, my tap water goes through a softener and 3-stage filter (NOT reverse osmosis).
Would I be okay to use this water for initial flushes then 2-3 flushes with distilled?
Click to expand...

Dumped through a gallon of distilled and is definitely gonna need a good rinse and flush. Don’t really wanna spend $50 on distilled unless I need to, some input from @mrblaine would be awesome.

I’d actually prefer to run it through my regular tap which only goes through the softener but not the 3-stage filter.
 
Last edited:
I installed a new mopar radiator in Aug. 6mo later it’s got a thin layer of sediment that’s not floating but will come up if a scrape it. Normal, or is something else going on?

IMG_0494.jpeg
 
red02tj said:
I installed a new mopar radiator in Aug. 6mo later it’s got a thin layer of sediment that’s not floating but will come up if a scrape it. Normal, or is something else going on?

View attachment 489613
Click to expand...

Mine has been worse than what you see even after thermocuring four different times over the past couple of years. I have a feeling that my issue is rust in the block that's not going way. But I'm also getting 3mm flakes of metal in the radiator along with rust build up.

The last time I filled the system, I used more concentrate than water for the first gallon then applied 50/50 mix. My thought was that maybe I've had water from the flush in the heater core even after draining from the block.

This isn't a solution to your issue, but this is where I'm currently at on the subject. Mine looked like yours does after only 3 months (between July and October). :( This was after a Prestone and then Thermocure flush.

I did another flush with Prestone only before my road trip in October.
 
  • Like
Reactions: red02tj
red02tj said:
I installed a new mopar radiator in Aug. 6mo later it’s got a thin layer of sediment that’s not floating but will come up if a scrape it. Normal, or is something else going on?

View attachment 489613
Click to expand...

I wouldn't be concerned about it. There's all kinds of gunk and dirt and rust on the inside of the engine block that is impossible to get reasonably get rid of for good. It will continue to build up over time. This is also why you flush the cooling system every 30k miles or every 2 years.
 
  • Like
Reactions: red02tj and MikeE024
Top Bottom
Back