Coolant Query: Preventive Drain and Fill vs. Fully Flush? (Page 1/3)
Vintage-Nut MAR 21, 03:50 PM
Countless PFF “coolant” threads often start with a question or a problem; my thread is more a coolant query…

I’ll start what I know:

*The pH balance of deteriorated coolant and depleted corrosion inhibitors become drastically more acidic over time which causes corrosion - very bad!

*It is critical to protect the engine by maintaining the system with a new antifreeze/coolant ‘cocktail’ which fresh corrosion inhibitors are very good!

*Fully flushing the system to eliminate all of the deteriorated coolant requires several distilled water flushing’s until the drained liquid is nearly colorless, which is another big ‘hassle’ before filling-up with full strength concentrate antifreeze.


I don’t know if any members are:

*Keep an eye on the condition of their coolant by testing the pH or other ‘tools’.

*Using other method to maintain the coolant than the full flush procedure.


Since I have five vehicles to maintain which two are daily drivers, I’m thinking to change my ‘classic’ Fiero coolant practice.

From: The full flush when ‘needed’
To: Drain ~ 7 quarts and fill-up with a 50/50 mix more often to avoid the ‘hassle’.

PFF Comments?
sleek fiero MAR 21, 04:05 PM
Yes it is important to drain ,flush and refill especially with the old style green coolant. also never mix green with longlife coolant. I use longlife because it only requires changing every 5 or 6 years. I have never used distilled water for flushing just my garden hose . That being said the important part is flushing out the contaminants the will spoil your new coolant and or engine. Save your distilled water for your battery. sleek
Patrick MAR 21, 04:18 PM

quote
Originally posted by sleek fiero:

I have never used distilled water for flushing just my garden hose... Save your distilled water for your battery.



That's easy for you or me to say, as we have "soft" (surface) water coming out of our taps here in Vancouver. It might be a totally different situation elsewhere, depending on the hardness of the water. So yeah, I also just use my garden hose to add water to my cars' cooling systems, but I probably wouldn't do so if my water was coming from a well or other potentially mineralized water source.

[This message has been edited by Patrick (edited 03-21-2023).]

Vintage-Nut MAR 21, 04:35 PM
Perhaps you didn’t understand my query…

A full flush means that the coolant has been deteriorated; i.e. low pH

By dumping half the coolant more often, say yearly, the coolant will never deplete the corrosion inhibitors and will keep the pH balance.

And yes, I know to never mix one type coolant to another and water quality matters!
VN
theogre MAR 21, 05:57 PM
I get your "idea" but don't to that. May see ph at "good" level but still make more problems and more HAZMAT waste.

You add New coolant to "Weak" coolant then New coolant instantly drops additives levels that prevent "rust," lube WP Seal, etc.

Is/Was Prestone product and maybe other brands that "renews" the additives to old coolant.
Problem is current Coolant products from most brands will have problems with this plan...

IOW If an Add Pack "can" (Small can or plastic bottle) is made for "Green Coolant" then Very Likely Won't work w/ DEXCool and many others.
Many old Add Pack "cans" you see at flea markets etc may not work even new Coolant that claim works w/ all coolant products available at most stores.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

armos MAR 21, 06:27 PM
When I got my car the coolant was rusty. I flushed it as best I could with a hose. I also replaced the radiator (one of the plastic tanks was leaking) and in a couple years, the heater core started leaking and also got replaced.

I've never tested the ph, I just periodically drain and refill.
My habit for 10 years was to do a simple drain and refill about once a year. I'd point the nose down (on a steep driveway) for the drain, and have always used regular green antifreeze.
I used to open the plastic drain valve on the radiator, but after several years of that it broke during an emissions test.
After being forced to do a radiator repair project in a parking lot, I hesitated to use that valve anymore. I settle for popping off one of the hoses instead.

Since moving to the suburbs I haven't kept up with it quite as well. I think I need to do another drain. If anything I should be doing it more often than I used to for a couple reasons.
It's flat here so I can't point the nose down as much, so I don't get as much out per drain.
I also feel the need to collect the coolant in a tub now, which makes it more cumbersome to deal with a large amount. It's been a long time since I lived in a place like this, but I'm afraid I'd upset some of the more sensitive suburbanites if they saw antifreeze run down my driveway.

[This message has been edited by armos (edited 03-21-2023).]

Spoon MAR 21, 08:39 PM

quote
Originally posted by armos:

but I'm afraid I'd upset some of the more sensitive suburbanites if they saw antifreeze run down my driveway.




I will add if a roaming dog or Miss kitty took a few laps of the curious drink, it could ruin their whole day.

Spoon


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"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

[This message has been edited by Spoon (edited 03-21-2023).]

pmbrunelle MAR 21, 08:59 PM
Coolant has pH buffers; their tendency is to keep the pH as constant as possible. Only once the buffers have become depleted will the pH drop. So I don't think that pH monitoring can be used to see how much buffers remain.

To determine how much buffers remain, I would remove a sample from the car, and then perform a titration with a strong acid.

The amount of strong acid needed to make the coolant switch from basic to acid indicates the buffering capacity of the coolant. Compare with brand-new coolant.

[This message has been edited by pmbrunelle (edited 03-21-2023).]

theogre MAR 21, 10:21 PM

quote
Originally posted by armos:
but I'm afraid I'd upset some of the more sensitive suburbanites if they saw antifreeze run down my driveway.

Beside killing animals, kids, and more... Is Illegal in most US states and a lot of other countries for dumping HAZMATs.

Many cities, often w/ state help, can trace HAZMAT entering the sewers because causes big $ problems to the pipes and treatment systems.
Plus Neighbors can simple report you same as other Code Violation on a home to the HOA, City, etc. but Illegal Dumping HAZMAT often means Huge Fines and/or Jail time.

Others,
New coolant has bitterant to prevent drinking but often doesn't work on animals. Depending how done by the manufacturer, The bitterant can "wear out" when coolant is in the car sim to AT oil where the Red Dye can fade and fools push "the oil is bad" scam.

Walmart and some other stores w/ auto service can take old coolant.
Example: Pep Boys before closing part store did take coolant and oil but don't know with running Service Only.
armos MAR 22, 03:21 AM

quote
Originally posted by theogre:
Beside killing animals, kids, and more... Is Illegal in most US states and a lot of other countries for dumping HAZMATs.


That's a bit dramatic. ethylene glycol is hardly a battery. It dilutes and breaks down quickly, it's only dangerous if somebody drinks it. In the old neighborhood there were some dogs and squirrels and deer and turkeys around but a hose and attention keeps them safe. The rabbits too, even though they were pests.
But yes, I know urbanized areas have laws about everything, and the closer people live together the more they worry about what everyone else is doing.

[This message has been edited by armos (edited 03-22-2023).]