Cooling system flush questions

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Jeepwalker

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Yeah, leave the 'flush' in there a lot longer than it says. And drive it. The heat makes the chemical reaction work better. Driving helps circulate it.

What year is your truck? Dexcool is great for aluminum-based engines. I wouldn't bother in my OBS though. The green stuff is a lot cheaper, get the extended range. I go to our local small-town chevy dealer and they will sell DexCool to me cheap out of their barrel (bring my own jug) for like 1/2 of what Walmart sells it for. They'll sell any oils cheap to me out of their barrels. The chrysler does that too. They have a mini-mountain of clean 1-gal milk jugs in the shop corner that people bring into the dealership ...lol. It's kind of funny. At the time they would sell me a gal of ATF +4 (which used to be super-expensive) for like 1/3 the price of walmart. Best if you walk in the side-door with your greasy clothes ..and jugs in hand. Dexcool is made by shell. Walmart sells it too. It's not as expensive as it used to be. If you already have dexcool vehicles, that it's probably better to standardize on the same coolant. If your other vehicles use green coolant I'd stick to that.

When you fill up your truck, use Distilled Water. Not tap water. It's like $1/gal at Aldi's or just about anywhere. If you use tap water you're just adding more mineral to your cooling system. The mineral comes out and attaches to areas where it'll be cooler (your radiator and heater core). So, for a couple bucks, it's the cheapest insurance you can buy.
 

sewlow

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I picked up one of these at a swap meet.
H/D mechanic buddy pointed it out. Had no idea what it was.
I recognized the brand name but...'Made in Denmark'?
Got it for $50.00. (Retails for $100.00-$120.00.)
Figured I'd use it once, if it even worked at all, then sell it & get my $$$ back out of it.
Didn't happen. Between mine & the other family member's dailies, plus Dad's fleet of antique/vintage cars, it's earned it's keep.
This thing works great.

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1998_K1500_Sub

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capture the original coolant drained from the rad draincock and the two block drains for appropriate disposal.

I pulled the block drains out the other day and caught the drainage in a clean, white pail.

I was amazed at the debris that came out of the engine... mostly small particulates in my case, but enough of them that I was genuinely surprised. I filtered the coolant before re-using it (I wasn't flushing the cooling system, I was draining it for engine service).

@Schurkey's always said to pull those drains. I've seen it for myself.
 

L31MaxExpress

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I pulled the block drains out the other day and caught the drainage in a clean, white pail.

I was amazed at the debris that came out of the engine... mostly small particulates in my case, but enough of them that I was genuinely surprised. I filtered the coolant before re-using it (I wasn't flushing the cooling system, I was draining it for engine service).

@Schurkey's always said to pull those drains. I've seen it for myself.
I have had to poke a screw driver through them on really neglected engines as the sludge and sediment completely blocks them.
 

Jeepwalker

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I filtered the coolant before re-using it (I wasn't flushing the cooling system, I was draining it for engine service).
How old was the coolant? Any old coolant should be pH checked or just replaced. Electrical load on coolant (from more sensors than in the past) can affect alkalinity. PH. Coolant can get old. Or if you bought the truck used, assume the PO used crusty tap water to add to the radiator (good way to mineralize it ..and the heater core).

But if yer coolant was fairly new, you'd be in good shape.
 

PlayingWithTBI

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Recently I drained and filled mine with the old school green stuff. Been using it since I bought this truck in 2002. I do this every year or two. To eliminate the tap or distilled water controversy, I bought premixed 50/50. guess what? Zerex is owned by Valvoline, ha ha.
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I read the back of the jug, it says diluted with de-ionized water. Well, de-ionized and softened water are quite similar, they both remove mineral ions. Softened water uses an ion bed which is regenerated by flushing with salt water where de-ionized water beds have to be replaced. Distilled water is fairly pure but, still conducts electricity. Reverse Osmosis water is similar to distilled but, it reduces PH too. We have a water softener and an R.O. system at our house. I'm not too worried if I use either in my cooling system but, I will only use R.O. water in my batteries.

When I was working at a food plant, I was responsible for designing and installing a 1.3 million BTU water heater and 75HP, 900 PSI pressure pump for wash down. All we used was a big 4 tank water softening system so it can regenerate one pair while running on the other. Anyway, after 2 years we tore the boiler down for cleaning and service, there was almost no mineral deposits inside the tubes. Just thought I'd share this :33:
 

Jeepwalker

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The only downfall of home-softened water depending on how yer water softener is, is a slightly higher salt amount. Could be a lot or could be minimal. But your right, low conductivity is better. Buying pre-mix is a good no-fuss way to go. Industrial de-ionized water probably is done through a column or another process, not salt (that would be an expensive way to go). I've used green antifreeze in my 03 Jeep 4.7HO for many years. The PO had the heads re-worked by a shop, and the shop put in the green anti-freeze. Chrysler insists ya MUST use their antifreeze ...car's got 233k miles on it and runs like a top. I pH check/adjust it ever few yrs.

Is that Extended Life antifreeze you bought? Doesn't say it on the front ...but read the back.
 

1998_K1500_Sub

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How old was the coolant? Any old coolant should be pH checked or just replaced. Electrical load on coolant (from more sensors than in the past) can affect alkalinity. PH. Coolant can get old. Or if you bought the truck used, assume the PO used crusty tap water to add to the radiator (good way to mineralize it ..and the heater core).

But if yer coolant was fairly new, you'd be in good shape.

Very good points.

The coolant was about three months old.

I always buy concentrate, when concentrate is available, and mix it with distilled water, FWIW.
 
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1998_K1500_Sub

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I read the back of the jug, it says diluted with de-ionized water. Well, de-ionized and softened water are quite similar, they both remove mineral ions.

Well, almost. I’ll build on @PlayingWithTBI 's comments.

Most (all?) home softeners use the ion exchange process, which removes calcium and magnesium ions and replaces them (exchanges) with sodium ions. So “ions” aren’t removed, they’re just replaced.

Sodium ions don’t react with soaps the way calcium and magnesium ions do to generate soap curds, thus the sodium ions are preferred in the home. Exchanging the ions achieves the objective, but there are still ions present.

Those softeners may add additional sodium ions because of tramp ions in the resin bed that find their way into the water, regardless of the exchange process.

Industrial softeners may use other processes.

So “deionized” water is just that.

“Softened” is not.

I wouldn’t bet the conductivity is significantly (orders of magnitude) different for the same water, before and after softening using ion exchange, given that ions remain. It would be interesting to check.

Store bought “distilled” water isn’t as pure as one might expect. Evidently, like with booze, the more distillation that takes place, the purer the product.

@PlayingWithTBI commented on RO water. I would expect naïvely that water that has been through multiple distillation phases (more so than store-bought) would be comparable. But actually, that’s just a guess.
 
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Schurkey

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What year is your truck? Dexcool is great for aluminum-based engines. I wouldn't bother in my OBS though.
On my small-block 88 K1500, the heater core, radiator, and intake manifold were aluminum as original equipment.

Dexcool is made by shell. Walmart sells it too. It's not as expensive as it used to be. If you already have dexcool vehicles, that it's probably better to standardize on the same coolant. If your other vehicles use green coolant I'd stick to that.
"Dexcool" is more of a license than a product. If the stuff meets GM specs, it can be called "Dexcool" no matter who makes it.

Texaco/Havoline was the original manufacturer. Now everyone and their brother has their own version.





Wanna try a cheap 'n' easy test for electrolysis? Get out your multimeter, set it for low voltage. Connect the negative lead to ground, and dangle the positive lead in the coolant via the radiator fill neck. See what voltage you get. Less is better, and it better be a small fraction of one volt.

There's two causes of "radiator voltage".
1. Improper grounds. The vehicle electrical system is grounding through the coolant.

2. Worn-out coolant. The dissimilar metals in the cooling system are using the coolant as electrolyte, the metals touched by the coolant are effectively a big battery.

www.freeasestudyguides.com/electrolysis.html
 
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