Chemical coolant flushes??

[KenO]

Haven't seen many threads here, so I wanted to ask. What is the general consensus of chemical flushes, such as the Prestone super flush stuff? I'm thinking of draining my coolant, re-filling with water and draining again, remove thermostat and then re-filling with water and adding the flush chemical. Run it until ti's up to temp, maybe take the vehicle for a drive, come home, and drain again. Flush with water, and then install new coolant.

Does anybody have any opinions on which one may or may not be better than the others?

 

[BobsArmory]

The only time I used a coolant flush was years ago. Right after I did I ended up with a water pump leak.

 

[mongo161]

The only flush that I used on a vehicles cooling system was Automatic Dishwasher Detergent, (Powder Form like Cascade), diluted in hot distilled water. I ran a couple of cycles of this for a day each then flushed the system with a garden hose a couple of times and finally ran plain distilled water for 2 cycles.

All I can say is it left the radiator sparkling clean and the dirt, sludge, filth that came out of the cooling system, with this treatment, left the system very clean.

I had no leaks or problems afterwards.

 

[bluestream]

Last coolant flush I did was in 1972. Waste of time and money imho.

I changed coolant every 10 years, and never had a problem. I do the Fords a bit sooner if they have a cast block

 

[Bgallagher]

Originally Posted By: mongo161
The only flush that I used on a vehicles cooling system was Automatic Dishwasher Detergent, (Powder Form like Cascade), diluted in hot distilled water. I ran a couple of cycles of this for a day each then flushed the system with a garden hose a couple of times and finally ran plain distilled water for 2 cycles.

All I can say is it left the radiator sparkling clean and the dirt, sludge, filth that came out of the cooling system, with this treatment, left the system very clean.

I had no leaks or problems afterwards.


+1 That is what the big rig guys use to clean the systems. Did it in my Equinox before I changed it from Dexcool to Peak Global. Did a great job cleaning out the insides.

 

[Rock_Hudstone]

On a clean well maintained system a chemical flush shouldn't be necessary. On the otherhand, a neglected system with coolant that has been left in way too long can definetly benefit.

However, I prefer the manufacturers coolant flush products i.e. GM Goodwrench or Ford and have used both with good results.
Can't say the same for the consumer Prestone flush.

 

[artificialist]

Back in the 1970s, my father had not properly maintained the cooling system of his 1971 Toyota Corolla, and major sludge and scale was making the car overheat. He used a DuPont cooling system flush that contained oxalic acid and when he drained the system, all the sludge and scale were gone and he a perfectly clean cooling system. Next the kit required him to use an acid neutralizer, so he did, and with proper maintinence, he never had another cooling problem with his 1971 Toyota Corolla.

 

[Trvlr500]

I'm one of the few here that still drives an oldie. It's a '73 Coupe DeVille. I had the engine rebuilt 97,000 miles ago. It was rebuilt about 13 years ago.

I have used a coolant flush almost every time I have changed the coolant every two years and have never gotten anything out of it except clear water when I run the distilled water through it. I can't really see the point any longer except out of curiosity.

Just recently, I used Zerex Super Cleaner (2 bottles) and ran the car for 10 hours instead of the recommended 3-6 and when I stuck a hose in the heater core and back flushed the block with a hose I didn't see anything come out at all. It was just clear water. As usual. I look down into the radiator and there is NONE of that crusty stuff that builds up around the orifices.

I ran 12 gallons of distilled through it with the thermostat out to get most of the traditional green coolant out. Then filled with distilled and Zerex and drove it around for 9 or 10 hours over a period of a week.

I then flushed the block and 15 year old heater core with a hose and ran 20 gallons of distilled through it over a period of another week. I never saw anything except clear water coming out of the engine. I refilled with 2 gallons of GO-5 and distilled along with a new thermostat and a couple of new hoses. Lower radiator and the heater hose.

I'm not going to even think about the cooling system for another 2 or 3 years. As everyone is saying. If you change the coolant regularly and you use the right coolant I can't see any reason to flush unless you just want to do it for the same reason I have done it. That is to see if anything nasty IS in there.

I have never used a hose before to back flush anything in the past. I have used heavier duty flushes though which are really hard to find anymore and nothing came out with those either.

The new coolant flushes, thanks to the EPA, are pretty weak compared to the older cleaners they had but even when I used those I never saw anything come out.

For a long time I used the old two part Prestone, two part powdered flush with the acid and neutralizer which is not available any longer. The I went the the Chevy dealer because they still carried the same thing with their name on it. Still nothing came out and that stuff was/is, if it's still available, a very strong flush.

I may try Irontite's "Thorough flush" the next time just for giggles. I just put Iron Tite's "All Weather Sealer" in because I did a used oil analysis and there is a minute, very minute, level of coolant in the oil. For all I know it's been that way for over 5 years which was when I replaced the water pump. These old behemoth's can take more abuse than the newer engines can. Within reason of course.

I'm too lazy to fix the area of ingress at this point. I'll take care of it when I need to replace the water pump which could be another 5 years or so. If their sealer works then I'll try their flush in a few years. They, of course, say it's the "bomb".

If there is still coolant in the oil at the next used oil analysis, which I never did until recently, I guess it will be time to pull the radiator, water pump, starter, oil pan and timing cover to fix the problem permanently because I highly doubt it's a head gasket. The car runs like a brand new car. I very rarely even feel it at idle.

 

[SZR48207]

Originally Posted By: mongo161
The only flush that I used on a vehicles cooling system was Automatic Dishwasher Detergent, (Powder Form like Cascade), diluted in hot distilled water. I ran a couple of cycles of this for a day each then flushed the system with a garden hose a couple of times and finally ran plain distilled water for 2 cycles.

All I can say is it left the radiator sparkling clean and the dirt, sludge, filth that came out of the cooling system, with this treatment, left the system very clean.

I had no leaks or problems afterwards.


This is an interesting idea. Do you remember what the ratio of Cascade to Hot Water was?

The cooling system on my F150 works fine, but there is some mild scale buildup possibly due to switching from factory green to Zerex G05 or having used tap water at one time. I sometimes get a chill down my spine when I think of the buildup so I'd like to clean it all out.

 

[abycat]

Originally Posted By: artificialist
Back in the 1970s, my father had not properly maintained the cooling system of his 1971 Toyota Corolla, and major sludge and scale was making the car overheat. He used a DuPont cooling system flush that contained oxalic acid and when he drained the system, all the sludge and scale were gone and he a perfectly clean cooling system. Next the kit required him to use an acid neutralizer, so he did, and with proper maintinence, he never had another cooling problem with his 1971 Toyota Corolla.



I could see that working for sure. OX is used in my industry and is a strong acid. i cant see a 71 having much aluminum stuff in it but new cars might have a prob with it. Also if you want kids in the near future dont smell it or get it on you. I doubt they sell it over the counter anymore cause OX is a bad acid. But you could talk to a pressure wash guy and get some. If you want to add it blindly to your rad but i bet it would be clean after that. Technically water wouold nutralize it But it would take a bit longer.

 

[SuperDave456]

In a 99 Taurus that I service. I've used the Prestone flushes with ok results. I did multiple drain and fills of plain old tap water and driving it to get up to temp with the heater on full blast, eventually getting near clear water out, then adding the Flush, and going for another drive with the heater on and all that jazz.

Still took me 8-10 drain and fills to get it cleaned up ok, never could get clean water out of it. That first time around. Took me 2 other cycles of drain and fills to get it cleaner.

Right now we are running Prestone All Makes All Models and it is looking like it is staying clean.

 

[Bgallagher]

Originally Posted By: Reddy45
Originally Posted By: mongo161
The only flush that I used on a vehicles cooling system was Automatic Dishwasher Detergent, (Powder Form like Cascade), diluted in hot distilled water. I ran a couple of cycles of this for a day each then flushed the system with a garden hose a couple of times and finally ran plain distilled water for 2 cycles.

All I can say is it left the radiator sparkling clean and the dirt, sludge, filth that came out of the cooling system, with this treatment, left the system very clean.

I had no leaks or problems afterwards.


This is an interesting idea. Do you remember what the ratio of Cascade to Hot Water was?

The cooling system on my F150 works fine, but there is some mild scale buildup possibly due to switching from factory green to Zerex G05 or having used tap water at one time. I sometimes get a chill down my spine when I think of the buildup so I'd like to clean it all out.



When I did it I used 1/2 cup of Cascade (try to find the powder with dawn in it, great at degreasing.) Mixed with a gallon of hot distilled water. Just make sure to really flush out the system with distilled to make sure all of the cascade is out. Works like a charm and the rest of the powder you can use in your dishwasher!

 

[JHZR2]

Good read... i was just thinking of putting some of the prestone or zerex flush through when swapping fluids. I dont neglect them though...

 

[crazy8]

Originally Posted By: KenO
Haven't seen many threads here, so I wanted to ask. What is the general consensus of chemical flushes, such as the Prestone super flush stuff? I'm thinking of draining my coolant, re-filling with water and draining again, remove thermostat and then re-filling with water and adding the flush chemical. Run it until ti's up to temp, maybe take the vehicle for a drive, come home, and drain again. Flush with water, and then install new coolant.

Does anybody have any opinions on which one may or may not be better than the others?



If the system looks clean and you see no rust/scale or oil build up in what you drain out it honestly will not need to be flushed, however I am old school and use dish washer soap when I change my coolant as a flush. I like the method that you plan on using, that is the way we were taught back in the 70's

 

[paulo57509]

I wonder if adding Lemi-Shine to the Cascade/Dawn mix would he helpful as well?

 

[Bgallagher]

Originally Posted By: paulo57509
I wonder if adding Lemi-Shine to the Cascade/Dawn mix would he helpful as well?



Good old Cascade doest plenty. I wouldn't add anything else. Just make sure the Cascade is fully dissolved before putting it in the system. Then flush flush flush

 

[Arved]

How is Cascade at getting rust out? I can see it doing a good job at degreasing and possibly de-mineralizing, but I've got an issue with rust in my cooling system.

What's the procedure for using Cascade? I get the predilute part. OK. How long do you run this with the cooling system up to temperature?

I've used Prestone Super Flush as directed. It did nothing to the coating of rust I see in my coolant tank or radiator hoses. I can wipe the rust easily with my finger, but I can't get my finger up 12" of hose, let alone through the entire block. Reminds me of the joke about the Proctologist who rebuilt an engine for a shop class - got extra credit for doing it through the tailpipe.

Thanks,

- Arved
Y2K Chrysler 300M w/197K miles

 

[Arved]

Also, I have to add, I'm very cautious about the idea of using Cascade on the cooling system. Dishwasher Detergent is very caustic. Aluminum radiators and engines (my 300M has aluminum block and heads) aren't anodized to protect against such harsh chemicals. If the Cascade does to my engine what it does to the aluminum coating on the bottom of my pots and pans, I don't want it anywhere near my cooling system.

To make matters worse, the formulation of Cascade with Dawn was changed for a 1 July 2010 mandate to eliminate phosphates. There have been many complaints about the detergent leaving a white residue and discoloring aluminum cookware. Is the solution worse than the cure? Perhaps so!

Unless Cascade is used in a much milder dilution than used in automatic dishwashers, I'm afraid this is a very bad idea.

Proctor and Gamble's suggestion to consumers is to use Vinegar to clean the black from the aluminum, and if that doesn't work, they have been known to pay damages. I'm sure that wouldn't include a new motor! But perhaps a (white) vinegar solution is an alternative to cleaning and descaling the cooling system. Chemically, this is similar to the other acidic treatments that have been suggested. I just worry that acids also act as electrolytes for galvanic corrosion, and I know the rust in my system is from galvanic corrosion between the aluminum engine and the cast iron water pump impeller and hard coolant lines (such as under the intake manifold, and to/from the heater core).

Timing (long enough to descale and derust, short enough not to promote more galvanic corrosion) must be key to using acids.

Warmest regards,

- Arved
Y2K Chrysler 300M w/197K miles

 

[DoubleWasp]

I recently did the Cascade flush. It left behind no rust at all that was on any metal part, but it could not knock that crud out of my rubber hoses. I have since had the cooling system apart, and saw no sign of any damage to the aluminum pieces.