Classic car coolant

Fabulous50s

Thread starter
Joined
Mar 19, 2022
Messages
225
John Deere Cool Gard II is my go to for everything that doesn’t get OE (in our case, my S-10, BMW, and Hondas all get OE coolant).

It’s a HOAT that is designed very well and is an advanced version (IMO) of good old G-05. Very compatible, very stable.
I emailed JD about the CoolGardII and it's compatibility with leaded solder and the other common metals in cooling. Their response was to ask my local JD dealer! Lol

Like the guy at the parts counter knows.......
 

Fabulous50s

Thread starter
Joined
Mar 19, 2022
Messages
225
I've read at least 10 threads on here and at least 10 threads on some classic car sites about Evans waterless coolant. And it seems a mixed bag.

Too viscous for a normal water pump to move, and poor heat transfer. But it doesn't boil and I get that. If I had some I'd try it, but the unknown of the possibility of a 230 degree engine just doesn't sit well. A lot of money without a known result.
 

Fabulous50s

Thread starter
Joined
Mar 19, 2022
Messages
225
Ya know, my old Toyota Supra has the same mix of metals - iron block, aluminum head and radiator, soldered brass heater core with brass piping. I suggest you consider Toyota Red, since you have the same mix of metals and Red does a great job with that. Clean out the system thoroughly before changing coolant chemistry. Do not use Toyota Pink premix. The newer Asian coolants, like Zerex's, won't do well either with that iron engine.
I think this is the direction I'm going in. Several classic car guys run Toyota Red.

I haven't looked into what makes it different from the IAT green we are all uses to. The silicate dropout over time in an engine that sits is the problem. I just flushed some crap out of the bottom of my 2 year old USA made aluminum radiator. This engine was stream cleaned, by me, on the engine stand. And there was absolutely no residue anywhere in the block etc.
 
Joined
May 25, 2005
Messages
917
Location
Arizona
The only issue I have with Peak 10X is there is pretty much ZERO information about the chemistry, inhibitors, or anything. In a newer vehicle, with aluminum everything, yes-but I’m not going to be the Guinea pig on an older cast iron engine, soldered radiator/heater core, or on a diesel (esp. one requiring SCAs like my 7.3 IDI). Has anyone ever seen an MSDS on 10X yet?
I can't go back to the Dex.... When I read "No 2EHA"... I was intrigued and asked around on this forum. (Some local mechanics also). We all seemed to be on the same page (At least for my 2001 Buick.) Anyhow.... Decided to simplify my life. Here's a blurb from the website:

PEAK® Antifreeze + Coolant is specially engineered to deliver
guaranteed superior lifetime protection†*

Its advanced universal
formula contains a proprietary blend of 10X the scale-fighting
inhibitors* coupled with robust organic additives to fight against
the damaging effects of scale deposits and corrosion.

PEAK Antifreeze + Coolant is free of 2-EHA, silicate, nitrite, borate and
amines, ensuring maximum cooling system performance for 10+
years/300,000+ miles*. It is compatible for use with any color or
type of antifreeze/coolant in the system
 

Fabulous50s

Thread starter
Joined
Mar 19, 2022
Messages
225
Do you think that somehow contributed to the fast radiator failure? You mention not liking the FCA Dexclone, but it doesn't sound like things worked out better here needing a radiator in a year on such a new vehicle.
I put the PGL in after i put the new rad in. If you look at the picture you will see the red/pink staining of the factory 1 year old Mopar Dexclone, ruining the 1 year old factory radiator.

It really just reinforced my dislike for Dexclone that much more.
 

JHZR2

Staff member
Joined
Dec 14, 2002
Messages
48,635
Location
New Jersey
I emailed JD about the CoolGardII and it's compatibility with leaded solder and the other common metals in cooling. Their response was to ask my local JD dealer! Lol

Like the guy at the parts counter knows.......

That’s a shame. They have had good information and comms in the past, including their old site literature, and even some info posted on here between the JD engineers and site members. Sounds like you didn’t get the right people.

An example is here:


Cool Gard II is a HOAT specifically designed for mixed metal, and a cross of old school and advanced technology (e.g., cooled egr, etc) engines. Nitrite free IIRC, so better for aluminum, but it’s tri-HOAT supposedly protects lots of stuff…

The issue as I understand it is that typically OATs don’t protect solder as well. Ive read where warranties can be voided if running OATs in brass/soldered applications. My understanding is that molybdates are really the best for protecting lead. They can’t always be prescribed, but options may include fast acting silicate, or triazoles, or other additives.

While not a VCA, this would imply that Cool Gard II is a HOAT (by claim of the engineer quoted in the link above) that has silicate, phosphate, and molybdate, which should be good for solder and mixed metal protection:



Supposedly this product includes phosphate and molybdate, and is good for protecting solder:


If nothing else, it is “conventional”. I don’t have data on it..


Coolant selection is tough for sure. So much info but so much that isn’t clear or sometimes conflicts….
 

Fabulous50s

Thread starter
Joined
Mar 19, 2022
Messages
225
I was reading up on the Toyota Red. Which looks like a phosphated IAT instead of Silicated. Don't know if that is better or worse. The Japanese have always like phosphates. The hard water thing doesn't apply as most on BITOG would mix with distilled or some type of processed water.

So many questions! It is interesting stuff though!
 
Joined
Jan 2, 2004
Messages
9,601
Location
California
I was reading up on the Toyota Red. Which looks like a phosphated IAT instead of Silicated. Don't know if that is better or worse. The Japanese have always like phosphates. The hard water thing doesn't apply as most on BITOG would mix with distilled or some type of processed water.

So many questions! It is interesting stuff though!
Toyota Red is good stuff, it uses benzoate instead of sebacate as the organic acid. Mix it with distilled - it’s more than capable of protecting iron. My first pick is Zerex original green, a silicated coolant promising xOAT life of 5 years/100K.

While old school green or G-05/Motorcraft Gold(a SiHOAT) would be my pick for a older car, Toyota Red is a good pick. Modern coolants aren’t factoring in solder/brass radiators and heater cores but controlled-atmosphere brazing has become a headache for Ford recently and they switched to Prestone Cor-Guard(Motorcraft Yellow). Old school green doesn’t have an organic acid, as a matter of fact, there is no acid in them. It depended on silicate and phosphate to provide cavitation and passivation of ferrous metals and aluminum, borate to control cavitation of the cylinder liners, an azole to protect yellow metals and copper and a captan chemical to protect solder.
 
Joined
Jan 3, 2020
Messages
615
Location
YYC
While old school green or G-05/Motorcraft Gold(a SiHOAT) would be my pick for a older car, Toyota Red is a good pick. Modern coolants aren’t factoring in solder/brass radiators and heater cores but controlled-atmosphere brazing has become a headache for Ford recently and they switched to Prestone Cor-Guard(Motorcraft Yellow). Old school green doesn’t have an organic acid, as a matter of fact, there is no acid in them. It depended on silicate and phosphate to provide cavitation and passivation of ferrous metals and aluminum, borate to control cavitation of the cylinder liners, an azole to protect yellow metals and copper and a captan chemical to protect solder.


I don't know how this old wives tale that modern coolants don't work well with brass and solder started, but it is absolutely 100% false. Some coolant manufacturers like Zerex publish their industry standard tests for coolant such as ASTM D2570 and D1384 which test for compatibility with brass, solder, cast iron, steel, aluminum, and copper. Look at the test results for yourself and you'll see that Dex-cool, and all the other modern coolants like G-48, and the Asian P-OAT's pass all the tests with flying colors.

Zerex PI sheets:

Zerex Dex-cool

Zerex Asian Blue (P-OAT)

Zerex G-48

Zerex Original Green (for comparison)
 

Fabulous50s

Thread starter
Joined
Mar 19, 2022
Messages
225
Notice the Solder loss is higher than the original Green in all the OATs, especially Dexcool.

All the OATs do better in one or two metals and worse in other metals, than IAT.

And somehow the Zerex origional green is spec'd for a 5 year life whereas all other IATs that I've seen only go 3 years. I'm just telling it how I've seen it. I'm not trying to be a wise guy.

That is the old wives tale, it has merit it seems.
 
Joined
Oct 9, 2004
Messages
12,571
Location
Cincinnati, OH, USA
Green IAT coolant has less silicate than days of old, and G-05/Premium Gold still have some silicate too. That’s why they seem to do well in cast iron engines & soldered radiator/heater core systems. Member Chris 142 has good insight on this subject, he’s stated numerous times in the past that OAT coolants (Dex,Prestone AMAM, etc.) have caused soldered radiators to fail. My theory on the old stuff is-why take a chance on ruining a brass radiator? It’s almost impossible to get one recored for a passenger car or light truck anymore.
 

Fabulous50s

Thread starter
Joined
Mar 19, 2022
Messages
225
I think my conclusion is that I'll stick to IAT coolants. Either the good old green, Toyota Red, or Cool-Gard II. I still haven't come to any conclusions as to which protects the best.

From all the white papers it looks like IATs do the best overall job with brass, solder, aluminum, cast iron, and silicone. The OATs all do better with aluminum, but worse with the other metals.

Evans waterless coolant is intriguing, but I'm not willing to risk the fuel vapor lock and possibly hotter running engine. The big V8 is very tight in there as it is. Just had to put an oil cooler in the fender. It's tighter than working on my old water cooled VWs!

I have the water pump out right now for a rebuild and flushed everything out.

I put a full port 1/4" brass ball valve on the rad drain with an elbow to point straight down to facilitate fast coolant changes.
 
Joined
Nov 4, 2020
Messages
21
I think my conclusion is that I'll stick to IAT coolants. Either the good old green, Toyota Red, or Cool-Gard II. I still haven't come to any conclusions as to which protects the best.

From all the white papers it looks like IATs do the best overall job with brass, solder, aluminum, cast iron, and silicone. The OATs all do better with aluminum, but worse with the other metals.

Evans waterless coolant is intriguing, but I'm not willing to risk the fuel vapor lock and possibly hotter running engine. The big V8 is very tight in there as it is. Just had to put an oil cooler in the fender. It's tighter than working on my old water cooled VWs!

I have the water pump out right now for a rebuild and flushed everything out.

I put a full port 1/4" brass ball valve on the rad drain with an elbow to point straight down to facilitate fast coolant changes.
Just wondering, when you used the PGL at work, have you ever seen an issue with it in any particular instances? I would think it's good enough that you wouldn't see any problems for the life of the engine, even if the IAT coolants are slightly better on the test sheets.
 

Fabulous50s

Thread starter
Joined
Mar 19, 2022
Messages
225
Just wondering, when you used the PGL at work, have you ever seen an issue with it in any particular instances? I would think it's good enough that you wouldn't see any problems for the life of the engine, even if the IAT coolants are slightly better on the test sheets.
No. But....there weren't many brass rads or heaters in the cars I worked on either. Just iron and aluminum.

It's the heater which I'm the most leery about. I remember Jeeps having a lot of heater core failures, and those were brass, but they always has green IAT in them too.
 
Top