Cooling system cleanliness

Even thermostat out this is taking for-ev-er.

These photos are the third, then fifth flush of tap water after draining the thermocure.

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After that I just opened the drain and am running hose water into the cap at just the right rate to keep the radiator full, and emptying the bucket when it fills up.

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My plan was to stop when it looked indistinguishable from tap water but I'm about 20 gallons in on this and every bucket I think ok, it'll be the next one.

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I'm also not sure what to make of all the foam I'm seeing at the cap.

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mrblaine said:
I don't have a subjective view. I'm not going to spend several hours swapping on new parts and wind up with other than perfect performance out of them by not making sure I've given them the best possible chance to perform perfectly and I can't do that with a rusty scaled out block.

I did get a brain tickle as I was writing that which reminded me of a gent that moved here from your neck of the woods with his TJ. I noted that he was only going to the store at night when the temps dropped below 90 and asked him what was up with that silliness? I can't drive it without it overheating so I go at night with the heater on full blast to be able to make it there and back.

Was it doing this before? No, never an issue up north but as soon as I get here, it starts. We did our normal stuff to it including the flush and he was then able to do all the normal stuff in our heat.

Point being, a lot of stuff slips by in different regions that won't fly for one second in others. Our cooling systems have to work very well.
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Agreed..I have bought jeeps and drove them home and then checked the coolant days later only to discover there was none. Open the petcock and a quart of black rusty water runs out. These did not overheat and ran at close to a normal temperature. That would never fly in your part of the country.
 
MountaineerTom said:
I'd say that's good.
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Strangely after being nearly perfectly clear, the following 2 flushes with distilled came out the shade of a few buckets earlier. No idea how that happens but I'm done. I wouldn't even know it wasn't clear if the bucket was any color at all besides white.

It's currently cooling off with the third charge of distilled water in it. I discovered I was short the constant tension clamp for the smallest of the main hose connections so I ordered one and it's either wait until it comes in on Tuesday or put it back together with one single cheap worm clamp, and I hate that. I've at least got it staged and ready to go.

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If you haven’t already, now’s also a good time to replace the rad and heater hoses.
 
freedom_in_4low said:
Strangely after being nearly perfectly clear, the following 2 flushes with distilled came out the shade of a few buckets earlier. No idea how that happens but I'm done. I wouldn't even know it wasn't clear if the bucket was any color at all besides white.

It's currently cooling off with the third charge of distilled water in it. I discovered I was short the constant tension clamp for the smallest of the main hose connections so I ordered one and it's either wait until it comes in on Tuesday or put it back together with one single cheap worm clamp, and I hate that. I've at least got it staged and ready to go.

View attachment 443957
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I think there is a distinct advantage to filling the system, circulating the fluid for 10 minutes and then draining it. I'd never do the trickle and drain thing, ever.
 
To my surprise, I found rust in my 2-year old coolant recently. I flushed the heater core and radiator in both directions after draining the block.

I had some sentiments at the top of the radiator near the cap, so I taped off the upper port and ran the hose to the bottom port which helped a decent amount. I’ll do another reverse flush during the first round of removing the thermocure.

Thanks to seeing older posts by @mrblaine and @pc1p I know to run a descaler in the system to help expose the rust under the scale before running the thermocure.
 
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red02tj said:
If you haven’t already, now’s also a good time to replace the rad and heater hoses.
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I'm doing the radiator hoses. Not doing the heater hoses, yet, only because I'm gonna cut them up to install a heater core bypass and I'll replace them with new when I can prove the heater core is leaking or not.
mrblaine said:
I think there is a distinct advantage to filling the system, circulating the fluid for 10 minutes and then draining it. I'd never do the trickle and drain thing, ever.
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I had myself convinced in my 95 degree and humid driveway that it couldn't be any different but thinking about it in the air conditioning I can see how it could make the water look more clear than it would look under the fill and flush method, since what's coming out of the drain is diluted by the fresh water being put in, and it likely takes more total volume of water to get the equivalent flushing effect since there's no time when a full 75% of it is being dumped out and replaced at once.

Curious...I picked up that 3-5 was somewhat typical, but what's the highest number of fill-run-dump cycles you've ever had to run before being satisfied with what was coming out? I did 5 with the tap water before going to the drain/trickle technique, and then 3 with distilled. I probably have enough distilled water to spare one more flush and still have some left for the final charge, but I'd have to make the drive to town for more distilled if I go back with more tap water.

Are you evaluating clarity by the stream or are you catching it in a white bucket like this?
 
freedom_in_4low said:
I'm doing the radiator hoses. Not doing the heater hoses, yet, only because I'm gonna cut them up to install a heater core bypass and I'll replace them with new when I can prove the heater core is leaking or not.


I had myself convinced in my 95 degree and humid driveway that it couldn't be any different but thinking about it in the air conditioning I can see how it could make the water look more clear than it would look under the fill and flush method, since what's coming out of the drain is diluted by the fresh water being put in, and it likely takes more total volume of water to get the equivalent flushing effect since there's no time when a full 75% of it is being dumped out and replaced at once.

Curious...I picked up that 3-5 was somewhat typical, but what's the highest number of fill-run-dump cycles you've ever had to run before being satisfied with what was coming out? I did 5 with the tap water before going to the drain/trickle technique, and then 3 with distilled. I probably have enough distilled water to spare one more flush and still have some left for the final charge, but I'd have to make the drive to town for more distilled if I go back with more tap water.

Are you evaluating clarity by the stream or are you catching it in a white bucket like this?
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Fwiw, I run like 5 or so rounds of distilled water through the system after doing the thermocure flush. I go by what the water looks like after running the thermocure (is it clear or does it still have a darker tint to it).

Based on my experience, it takes more flushes if you don’t drain the block. I didn’t drain the block on my 99 that I had for a short period and eventually I just said “good enough” after running like 18 gallons through it since the light tint wasn’t going away.

I believe I determined the block held about one gallon of fluid, so I ran one gallon of concentrate and then topped off with 50/50. I believe that math checks out with what Blaine mentioned to get him to 70/30 but let me know if I’m off on that.
 
freedom_in_4low said:
Strangely after being nearly perfectly clear, the following 2 flushes with distilled came out the shade of a few buckets earlier. No idea how that happens but I'm done. I wouldn't even know it wasn't clear if the bucket was any color at all besides white.

It's currently cooling off with the third charge of distilled water in it. I discovered I was short the constant tension clamp for the smallest of the main hose connections so I ordered one and it's either wait until it comes in on Tuesday or put it back together with one single cheap worm clamp, and I hate that. I've at least got it staged and ready to go.

View attachment 443957
Click to expand...

I am dealing with the exact same shit right now. I tried to avoid pulling the thermostat since I just rebuilt the whole damn cooling system. To say that was dumb is the understatement of the century. I ordered a new thermostat gasket today and get to continue the pain in the ass later this week.
 
freedom_in_4low said:
Strangely after being nearly perfectly clear, the following 2 flushes with distilled came out the shade of a few buckets earlier. No idea how that happens but I'm done. I wouldn't even know it wasn't clear if the bucket was any color at all besides white.

It's currently cooling off with the third charge of distilled water in it. I discovered I was short the constant tension clamp for the smallest of the main hose connections so I ordered one and it's either wait until it comes in on Tuesday or put it back together with one single cheap worm clamp, and I hate that. I've at least got it staged and ready to go.

View attachment 443957
Click to expand...

Why didn’t use the block drain option?
When I flushed, I drained the block like 6 or 7 times. It is pretty simple to open it, it is between the cats. All you need is the 8mm square head if I am not mistaken.
 
I use my Dad’s method for flushing and refill. I only flush when I need to replace coolant due to age of failed testing.
I drain the system and remove thermostat.
Fill with tap water and 1cup of borrax and run it for a couple of days.
Drain and fill with tap water run for a while. X3
Drain, find coolant capacity and add 1/2 of that with coolant. Top off with distilled water.
We have surface water where I live so there is low mineral content.
Never have had mineral buildup or rust flakes on any vehicle and I keep them forever and routinely get 300K out of them.
My diesels get anti cavitation additive.
I also use a Hydrometer to check coolant temp/freez protection status. I also have coolant test strips.
 
mrblaine said:
I lack the visual acuity to determine the fluid condition by any other method than viewing it in a clean white bucket.
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I'm not sure anybody has that acuity. I just wanted to make sure I wasn't pursuing a standard of clarity beyond what's reasonable to expect. I learned on my first TJ radiator flush that it can look crystal clear hitting the ground and not be clear at all in a bucket.
 
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TexasTJ2004 said:
Why didn’t use the block drain option?
When I flushed, I drained the block like 6 or 7 times. It is pretty simple to open it, it is between the cats. All you need is the 8mm square head if I am not mistaken.
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Just seems like a pain to get to and likely to be rusted in place and want to break off. I haven't heard of that happening as much as I would expect though.
 
Bigmac said:
I am dealing with the exact same shit right now. I tried to avoid pulling the thermostat since I just rebuilt the whole damn cooling system. To say that was dumb is the understatement of the century. I ordered a new thermostat gasket today and get to continue the pain in the ass later this week.
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It is always a good idea to order in a couple of spare thermostat housing gaskets, a spare radiator cap, and a spare thermostat.
 
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freedom_in_4low said:
Just seems like a pain to get to and likely to be rusted in place and want to break off. I haven't heard of that happening as much as I would expect though.
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I just did this this past weekend. It wasn't that bad with the proper socket extension and 24" breaker bar. Where I screwed up was I'm 90% sure I crossthreaded it when I put it back. But at least it is up to torque specs and doesn't leak.

I will absolutely try to avoid taking it out again.
 
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mrblaine said:
It is always a good idea to order in a couple of spare thermostat housing gaskets, a spare radiator cap, and a spare thermostat.
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I replaced my cap with a brand new stant during the refresh just because... Then it did this...
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