Looking for a coolant recommendation for a new old truck.

[Likesdirt]

So I'm building a '77 squarebody Chevy here in Alaska.

New aluminum heater core, new aluminum radiator, clean cast iron block with aluminum heads, new coolant recovery bottle.

I'm looking for a coolant recommendation - needs to be readily available as concentrate since 50/50 isn't strong enough and will freeze. Mail order coolant need not apply.

Current contenders are Shell or Chevron semi truck, Prestone non-max, G05, and old school green.

Any ideas?

 

[clinebarger]

Dexcool

 

[tedsweet]

g 05

 

[JHZR2]

Dexcool

Not a good choice for a retrofit or for engines not really designed for it. Ideally there is a pressurized degas bottle.

I’d run G-05, or John Deere Cool Gard II.

 

[SR5]

G-05

G-05 offers the best of both worlds, fast acting IAT (silicates) for immediate protection, and long lasting OAT for long life protection, as a hybrid package. G-05 is also 2-EHA free to protect your plastics, and with low enough silicates to not cause any deposit issues.

 

[ka9mnx]

Old school green (SuperTech) If Walmart is in your area. It's what goes in everything I own. It's not really old school green.

 

[nwjones18]

Not a good choice for a retrofit or for engines not really designed for it. Ideally there is a pressurized degas bottle.

I’d run G-05, or John Deere Cool Gard II.

Do people really see issues in real life using universal coolants (dexcool clones) ? We have 75 and 77 and 88 F-150's and a 89 Bronco all using universal coolants. 20+ years of ownership on all of them and zero coolant related issues.

I've heard the 2-EHA arguments a million times and I have changed intake manifold gaskets on a 4.3 that had never had the dexcool changed. Other than that neglected and common example I've never seen any harm done.

 

[JavierH19]

From what I hear cat ec-1 is one of the best coolants and if starting from new dry components i'd use that. Walmart sells peak final charge which is ec-1 and claims 10/10 on the water pump test.

I run universal green in my trucks since I never cared to fully flush the system just yank the hose and refill. Over 620k combined on those iron blocks since new. You'd be fine with peak 10y 100k universal. I always cut the interval in half on old iron blocks since i was told to do that to make them last and still do but on aluminum engines it's likely not needed. Dexcool would be fine i know they changed it so it's not the same as people remembered.

 

[JHZR2]

Do people really see issues in real life using universal coolants (dexcool clones) ? We have 75 and 77 and 88 F-150's and a 89 Bronco all using universal coolants. 20+ years of ownership on all of them and zero coolant related issues.

I've heard the 2-EHA arguments a million times and I have changed intake manifold gaskets on a 4.3 that had never had the dexcool changed. Other than that neglected and common example I've never seen any harm done.

I still use dexcool in my 1998 S-10 ZR2 4.3 that I’ve owned since new. But all the same, my answer is yes, for a few reasons:

1) I don’t know how to guarantee that 50yo silicates aren’t still somewhere in the system. Small amounts of silicated antifreeze are a cause of dex sludge formation.

2) another cause of dex issues is older design systems with an overflow tank, angled/old style radiator caps, etc. if one isn’t very cautious with that, there is the potential for aerating the coolant which is another cause of degradation.

3) lack of comparability with legacy materials. Granted that’s a 2-EH issue, not necessarily a dexcool one.

In general, I’m not particularly interested in self-defined “universal” coolants. Because they’re generally a compromise. The burden of proof is high. And a universal that has 2-EHA just strikes me as a liability, particularly when the OE coolant requirements didn’t have it.

Bottom line is that these are old engines, designed with a different chemistry in mind. To me, and based upon experience in my fleet, JDCG is a good one because it has superior performance to all other coolants (they have the evidence, though the documentation online on their site used to be more comprehensive).

So Id run an established coolant that is common and generally consistent with the design of that engine and system. To me that means a silicated coolant, ideally a HOAT. Which means G-05 or JDCGII, since there aren’t great legacy green options any more and they didn’t necessarily work perfect back when.

From what I hear cat ec-1 is one of the best coolants and if starting from new dry components i'd use that. Walmart sells peak final charge which is ec-1 and claims 10/10 on the water pump test.

I run universal green in my trucks since I never cared to fully flush the system just yank the hose and refill. Over 620k combined on those iron blocks since new. You'd be fine with peak 10y 100k universal. I always cut the interval in half on old iron blocks since i was told to do that to make them last and still do but on aluminum engines it's likely not needed. Dexcool would be fine i know they changed it so it's not the same as people remembered.

I’m sure it is. But as I understand, most variants include nitrites. I believe they’re harder on aluminum. OP has a lot of aluminum in the system. There are aluminum passivating materials, as I recall, molybdate amongst others (other folks have a better grasp of all the coolant functionalities than I do).

https://www.chevronlubricants.com/e...hinery/nitrited-or-nitrite-free-coolants.html

Is agree that old school green would be ok, but there aren’t as many trustworthy variants, IMO, and also IMO, G-05 and others surpassed the standard/low silicate green long ago and are well proven with iron and aluminum.

I also agree that especially for iron, more often is better, but I think that’s universally relevant since coolant chemistry does deplete.

 

[crashz]

Awesome! Can't wait to see it when its done (hint, hint)!

 

[Chris142]

needs to be readily available as concentrate since 50/50 isn't strong enough and will freeze.

Curious as to what ratio you use there?

 

[JavierH19]

I still use dexcool in my 1998 S-10 ZR2 4.3 that I’ve owned since new. But all the same, my answer is yes, for a few reasons:

1) I don’t know how to guarantee that 50yo silicates aren’t still somewhere in the system. Small amounts of silicated antifreeze are a cause of dex sludge formation.

2) another cause of dex issues is older design systems with an overflow tank, angled/old style radiator caps, etc. if one isn’t very cautious with that, there is the potential for aerating the coolant which is another cause of degradation.

3) lack of comparability with legacy materials. Granted that’s a 2-EH issue, not necessarily a dexcool one.

In general, I’m not particularly interested in self-defined “universal” coolants. Because they’re generally a compromise. The burden of proof is high. And a universal that has 2-EHA just strikes me as a liability, particularly when the OE coolant requirements didn’t have it.

Bottom line is that these are old engines, designed with a different chemistry in mind. To me, and based upon experience in my fleet, JDCG is a good one because it has superior performance to all other coolants (they have the evidence, though the documentation online on their site used to be more comprehensive).

So Id run an established coolant that is common and generally consistent with the design of that engine and system. To me that means a silicated coolant, ideally a HOAT. Which means G-05 or JDCGII, since there aren’t great legacy green options any more and they didn’t necessarily work perfect back when.



I’m sure it is. But as I understand, most variants include nitrites. I believe they’re harder on aluminum. OP has a lot of aluminum in the system. There are aluminum passivating materials, as I recall, molybdate amongst others (other folks have a better grasp of all the coolant functionalities than I do).

https://www.chevronlubricants.com/e...hinery/nitrited-or-nitrite-free-coolants.html

Is agree that old school green would be ok, but there aren’t as many trustworthy variants, IMO, and also IMO, G-05 and others surpassed the standard/low silicate green long ago and are well proven with iron and aluminum.

I also agree that especially for iron, more often is better, but I think that’s universally relevant since coolant chemistry does deplete.

Forgot to mention it's the new Peak final charge pro series that came out a couple years ago that's available at Walmart as of recently. It's the newer phosphate, borate, silicate, nitrile and 2 EHA free version. States it's fully compatible with all metals including aluminum and all gasket, seal, and hose types from what they say and say to use it in everything fleets run if flushed properly. Says it's formulation is one of the least abrasive which i like the sound of. Now that my iron blocks are pretty old I think i'll flush them thoroughly and use this peak coolant next time.

 

[slacktide_bitog]

Green, G05, or one of the non-2EHA Peak universal coolants (Titanium or PGL)

Peak and Zerex still make the silicate green, and Napa carries both.

 

[JHZR2]

Green, G05, or one of the non-2EHA Peak universal coolants (Titanium or PGL)

Peak and Zerex still make the silicate green, and Napa carries both.

As I understand it, the silicate green sold at these places is different from the older versions. Probably more like a green HOAT perhaps.

 

[slacktide_bitog]

As I understand it, the silicate green sold at these places is different from the older versions. Probably more like a green HOAT perhaps.

Even if they are slightly different from the older versions, they are still usable in the OP's truck

The lower silicate will not be a problem.

 

[clinebarger]

Not a good choice for a retrofit or for engines not really designed for it. Ideally there is a pressurized degas bottle.

I’d run G-05, or John Deere Cool Gard II.

Several modern GM models don't use a pressurized degas bottle, The 3.6L Traverse & all it's derivatives is a good example.

We can't blame Vortec 4.3L/5.0L/5.7L intake gasket failures on Dexcool or 2 EHA alone as they would fail at the intake ports as well.

 

[Arc]

So I'm building a '77 squarebody Chevy here in Alaska.

New aluminum heater core, new aluminum radiator, clean cast iron block with aluminum heads, new coolant recovery bottle.

I'm looking for a coolant recommendation - needs to be readily available as concentrate since 50/50 isn't strong enough and will freeze. Mail order coolant need not apply.

Current contenders are Shell or Chevron semi truck, Prestone non-max, G05, and old school green.

Any ideas?

If it has to be readily available then just buy whatever is readily available in your location.

 

[JHZR2]

Even if they are slightly different from the older versions, they are still usable in the OP's truck

The lower silicate will not be a problem.

Don’t disagree. There just may be better options now…

 

[JHZR2]

Several modern GM models don't use a pressurized degas bottle, The 3.6L Traverse & all it's derivatives is a good example.

We can't blame Vortec 4.3L/5.0L/5.7L intake gasket failures on Dexcool or 2 EHA alone as they would fail at the intake ports as well.

The pressurized bottle was claimed to be a design attribute that helped prevent some air contact type degradation. Of course this was all discussion back in the early 2000s… long ago now!

If newer designs helped to avoid leaks or avoid airation at the surface then that may resolve a lot. At the time the pressurized system was thought to be a solution, and lack of issues with engines purposely made to take dex, vs the legacy engines, was often identified.

I (still have) my 98 S-10 that needed a LIM gasket due to Na/K showing up via used oil analysis, in small amounts in the oil. But my 2004 Saab 9-3 had the pressurized bottle and it was claimed to be part of the best practices.

The angled radiator cap was also cited. Perhaps the scenario was more the radiator than the overflow in the end?

I’ve never had issues since the LIM gasket with my 98, and the original system is pristine, but it came from the factory with Dex, and has never seen a drop of anything else.