JD Cool Gard II slipping out of system after all aluminum radiator change

[JHZR2]

I love JD Cool Gard II in my old diesels. I have it running perfectly successfully in the following:

1996 Dodge Ram Cummins 445k mi
1996 Dodge Ram Cummins 266k mi
1991 MB 350SD 203k mi
1991 MB 300D 233k mi

Well, the 350SD had it perfect. No issues. Had the OE plastic radiator.

In the summer I had a Chinesium fan clutch fail, throw the fan into the radiator. That story is on here. The OE plastic radiators are NLA, so the only choice is a welded aluminum radiator that fits in the same spot. Seems to work fine. But I recently noticed some oddities.

The cool gard seems to be seeping out!

Noticed this yesterday:

Clamp is plenty tight. Wasn’t chanced or adjusted in probably a decade. Didn’t need to loosen it when changing radiators.

OK, so maybe that’s not alarming…. Well, it’s seeeping through the hose:

It’s definitely yellow coolant. It’s not enough to change the level at all. In fact, a few thousand miles after changing that radiator, the level is still at the full top of the pressure bottle.

It dries to this:

But it’s more…

It’s seeping at the upper purge hose…

And the drain plug.

Nothing is at a torque level that I’d be comfortable with going tighter.

Maybe the one hose has failed internally?

I’m not blaming Cool Gard. As I mentioned, I’ve ran it for a long time in multiple diesels with great success and very clean systems.

But just an interesting observation. All in one vehicle. No indications of anything anywhere else on any of the other vehicles.

 

[fantastic]

Something in the rubber causing determination with the CG? Otherwise new rubber hoses & clamping down to torque spec, then using some gasket maker around the current leakage points. You could try without the gasket maker & new hoses may do the job. You'd be surprised how much clamp is needed to seal up properly. Could you get the torque spec from an online forum? maybe someone has an idea. New rubber as it sounds like they are original to the car.

You could put gasket maker on these old ones but like I mentioned if they are original it's time to replace them as they are probably getting harder. Put some gasket maker around the plug to prevent seapage or proper torque spec?

 

[JHZR2]

Something in the rubber causing determination with the CG? Otherwise new rubber hoses & clamping down to torque spec, then using some gasket maker around the current leakage points. You could try without the gasket maker & new hoses may do the job. You'd be surprised how much clamp is needed to seal up properly. Could you get the torque spec from an online forum? maybe someone has an idea. New rubber as it sounds like they are original to the car.

You could put gasket maker on these old ones but like I mentioned if they are original it's time to replace them as they are probably getting harder. Put some gasket maker around the plug to prevent seapage or proper torque spec?

But here’s the strange thing. I ran CGII in those hoses for thousands of miles since I got the car. No issues.

When the radiator was busted, I obviously removed the hose at the old radiator, I didn’t touch the head-side hose connection. There was no reason to.

So the hose position, and torque on that clamp is the same as it has been for a decade or longer with no leaking or other issues at all.

It’s only recent.

 

[fantastic]

But here’s the strange thing. I ran CGII in those hoses for thousands of miles since I got the car. No issues.

When the radiator was busted, I obviously removed the hose at the old radiator, I didn’t touch the head-side hose connection. There was no reason to.

So the hose position, and torque on that clamp is the same as it has been for a decade or longer with no leaking or other issues at all.

It’s only recent.

The GC is leaking through the nylon reinforced locations. It must be permeating through the rubber b/c I'm not sure how else that could happen short of some internal damage which I doubt. The old rubber looks like it's absorbing the coolant HA! It is a head scratcher other than just going at it in a logical way of "Time to replace".

 

[JHZR2]

The GC is leaking through the nylon reinforced locations. It must be permeating through the rubber b/c I'm not sure how else that could happen short of some internal damage which I doubt. The old rubber looks like it's absorbing the coolant HA! It is a head scratcher other than just going at it in a logical way of "Time to replace".

Yeah definitely time to replace! Never seen this before.

 

[Marcozi]

Hmmm, there's chemical reaction going on. I wonder if the aluminum radiator has some other metals that are reacting with the coolant.

 

[Rand]

Hmmm, there's chemical reaction going on. I wonder if the aluminum radiator has some other metals that are reacting with the coolant.

CG II is fine for Aluminum including blocks.

Only thing I can think of is internal hose damage from replacing radiator..
similar to when a tire gets air between the liner and tread.

 

[Nukeman7]

I experienced similar weepage scenario numerous years ago when I switched from Prestone green antifreeze to orange DEX-Cool coolant in a Ford Bronco with the 351W. Within a week, DEX-Cool started slowly migrating through the reinforced fabric hose edges and the clamped outlet connections, both on the engine side and the radiator inlet/outlet. Installed new hoses and changed to constant tension clamps and the seepage resumed a few weeks later. Finally, I drained and flushed the cooling system and refilled with Prestone green and never had any leakage again. Never figured out why it only leaked with DEX-Cool, but I assumed it was due to the chemistry difference as the viscosity did not appear to be different at a 50/50% mixture.

What is strange with JHZR2's situation is the JD Cool-Gard is also leaking from the metal drain plug on the new radiator. Is that sealed with a nitrile rubber o-ring or something else? I'd suggest resealing the drain plug threads with Teflon tape if you drain it to replace the radiator hoses.

 

[JHZR2]

I experienced similar weepage scenario numerous years ago when I switched from Prestone green antifreeze to orange DEX-Cool coolant in a Ford Bronco with the 351W. Within a week, DEX-Cool started slowly migrating through the reinforced fabric hose edges and the clamped outlet connections, both on the engine side and the radiator inlet/outlet. Installed new hoses and changed to constant tension clamps and the seepage resumed a few weeks later. Finally, I drained and flushed the cooling system and refilled with Prestone green and never had any leakage again. Never figured out why it only leaked with DEX-Cool, but I assumed it was due to the chemistry difference as the viscosity did not appear to be different at a 50/50% mixture.

What is strange with JHZR2's situation is the JD Cool-Gard is also leaking from the metal drain plug on the new radiator. Is that sealed with a nitrile rubber o-ring or something else? I'd suggest resealing the drain plug threads with Teflon tape if you drain it to replace the radiator hoses.

But to be clear, it didn’t do this with the OE MB radiator that I had in there before. So it could be damage from pulling the hose, sure. But again, the odd thing is that the major seepage is on the side I didn’t even touch.

The plug was sealed with teflon tape. No luck.

 

[doitmyself]

But to be clear, it didn’t do this with the OE MB radiator that I had in there before.

I wonder if it's possible that the Coolgard has more surfactant in it, making the surface tension less?

"The chemicals reduce the surface tension of plain water so it's easier to spread and soak into objects, which is why it's known as “wet water.”.
"A surfactant, or surface active agent, makes water more efficient by making water wetter. Water becomes "wetter" by lowering its surface tension. The surface tension of water is a force that defines its behavior."


EDIT: Oops. I didn't read and comprehend very well. I thought you stated "OE MB radiator fluid". My bad.

 

[KrisZ]

Perhaps the difference here can be attributed to the coolant itself? Batch difference, dare I blame rona for this?

 

[JHZR2]

Perhaps the difference here can be attributed to the coolant itself? Batch difference, dare I blame rona for this?

Dubious.

 

[cptbarkey]

The first photo the hose looks swollen. Is it an old hose over 10 years old or a new hose? Is the coolant flowing above 20psi pressure?

 

[JHZR2]

The first photo the hose looks swollen. Is it an old hose over 10 years old or a new hose? Is the coolant flowing above 20psi pressure?

33 years. Believe it’s 1.2 bar, so 17psi.

 

[cptbarkey]

33 years. Believe it’s 1.2 bar, so 17psi.

That hose has performed admirably but deserves a viking funeral.

 

[ripcord]

John Deere and Mr. Mercedes hate each other from way back when Mr. Mercedes called John a Hinterwäldler. Mixing the two is asking for trouble.