Cooling System Flush Chemical

[The Critic]

I'm going to perform a cooling system flush on my Saturn this coming Thursday, and I want to use a quick flush product prior to refilling with new coolant.

I've used the Prestone Super Radiator Cleaner before, but it requires three to six hours of driving. The temperature sometimes gets below freezing at night, so it's probably not a good idea to use that stuff during this time of year (all of the antifreeze has to be drained out first). So, I think I'm stuck with using one of the quick flush products.

I see that Prestone offers a super radiator flush product, as does Zerex. Which one is better? Or should I call up the local auto repair shops and buy the BG version?

Thanks.

 

[Audi Junkie]

All I know is the only flush that is supposed to be effective is a 2-part, acid+neutralizer.

 

[benjamming]

Why the need for flush chemicals? Have you not kept up with cooling system maintenance?

 

[JHZR2]

Originally Posted By: Audi Junkie
All I know is the only flush that is supposed to be effective is a 2-part, acid+neutralizer.


Ditto... MB advocates citric acid flushes, and our original cooling equipment works great after 12-27 years of use.

MB will do acitric acid flush and refill with g-05 for roughly $120 at a decent dealer... If you find an MB only shop, they should know the process and do it on a non-MB vehicle with your coolant of choice. I am not aware that the citric acid flush system chemicals are sold OTC at dealers.

 

[Donald]

Unless really neglected you should not really need a flush. What do you see when you take off the radiator cap?

 

[The Critic]

Originally Posted By: Audi Junkie
All I know is the only flush that is supposed to be effective is a 2-part, acid+neutralizer.

I've been trying to find that stuff, but no luck. Know where I can get some?

Originally Posted By: JHZR2
Ditto... MB advocates citric acid flushes, and our original cooling equipment works great after 12-27 years of use.

MB will do a citric acid flush and refill with g-05 for roughly $120 at a decent dealer... If you find an MB only shop, they should know the process and do it on a non-MB vehicle with your coolant of choice. I am not aware that the citric acid flush system chemicals are sold OTC at dealers.

I did a quick google search for the Prestone Super Radiator Flush's MSDS. It's old, but it shows that it contains citric acid. I can't find a newer one, but does anyone know if the formula is still the same? It's onsale for $2 at NAPA right now, perhaps this is the stuff that I need?

Originally Posted By: Donald
Unless really neglected you should not really need a flush. What do you see when you take off the radiator cap?

Just coolant. No build-up. The coolant seems to darken quickly. The first two coolant flushes were done at five year intervals when they were supposed to be done at three year intervals, therefore the system may be dirty. I just want to use a chemical to clean the system for routine maintenance.

 

[Fordiesel69]

My expeiance has always been bad with flush chemicals. I am Mr perfection myself and always like to change all the fluids and get everything sparkling clean. Then I discover a heater core leak, intake gasket leak, radiator tank solder joint, and the list goes on and on............

Skip the flush an bring your service intervals down to 2-3 years. I you want, take your radiator out and flush backwards thru it with water at tap pressure. Same for heater core, reverse hoses and run water thru reverse.

 

[Donald]

Why not try a flush tee to do the flush, true you you end up with regular water in the system, but it should do a decent job with no chemicals. You can always buy a foot or two of radiator hose and then not have to spice the tee into the heater hoses.

If that does not get it clean enough you can always then try a flush chemical.

 

[The Critic]

Originally Posted By: Donald
Why not try a flush tee to do the flush, true you you end up with regular water in the system, but it should do a decent job with no chemicals. You can always buy a foot or two of radiator hose and then not have to spice the tee into the heater hoses.

If that does not get it clean enough you can always then try a flush chemical.

Heater hoses are tough to reach. I bought the Prestone chemical today. It was less than $3 and the label says it contains sodium citrate. I'll give that a try first. If it doesn't work, I'll try the RMI-25 or try the backflush method.

 

[ConfederateTyrant]

I've used the Prestone flush, and some sediment was indeed loosened and expelled...but then again the system hadn't been flushed as often as it should have.

 

[nthach]

I've never had to flush 2 of our cars, since they only saw Toyota/CCI coolant. Ditto for my friend's Honda.

I've had to on occasion with an old Toyota Cressida, a Nissan Quest, and 2 Mercedes that saw Prestone and Dex-Cool.

The newer Prestone flushes use sodium citrate, the same stuff that keeps apples from going brown.

 

[tdi-rick]

Talking to the chemists at DeVille Australia (manufacture Tectaloy Coolants that most commercial coolant specialists use here) they advocate always using an acid based flush for OAT/HOAT coolants and an alkali one for conventional anti-corrosion based ones, much as the fella's above have advocated from MB.

Yes, I have to specially order it from a wholesaler. A number of parts suppliers won't stock it anymore.

 

[Shannow]

In the big stuff, we use a lot of citric acid flushes...pretty benign stuff usually. Used to use a "bone" inhibitor on copper.

Procedure used to be TSP for oil removal, citric acid for corrosion removal, then a peroxide treatment to get rid of the acid, and ammonia soak for storage.

The chemistry would be the same, but the consultant would cost you $30g.

 

[vxcalais]

TDI-RICK, I usually use the Tectaloy Mukowt from Repco's etc. I am sure its citrus based. Nulon have one as well. I know there is a workshop version of Mukowt TD?, which may be the one you are talking about (acid based).