Green out, JD Cool Gard II in - murky

[JHZR2]

1996 Dodge Ram Cummins 5.9 turbo diesel.

Had some kind of green, loooked clean and good. Flushed out with water, ran it to temp, flushed a few more times to clear water.

Installed four gallons of 50/50 mix of distilled water and JD Cool Gard II. It’s a beautiful yellow color.

But when I remove the radiator cap, terribly murky drips come off. Seems somewhat murky in the radiator too.

I drained the radiator and replaced both hoses. I didn’t pull a block drain, but installed 16 of 26 quarts.

The best example is what dropped off the cap.

Thing with the cap is that I washed it. So if it was additive clash, there’s not much additive on the cap to clash. And the thing with the radiator is that it did this before turning the engine on. So it’s not like it’s gone through a number of heating cycles. Water flushed through was clear, so I don’t think there was a lot of remnant residue there.

I’m not opposed to driving a bit and then replacing again. Not a fan of it, but it seems like best practice. But any thoughts on this mess?

 

[doitmyself]

Probably has gunk clinging to the surfaces that the water rinse did not address. I would be inclined to use some type of mild off the shelf cleaner in the system and then many multiple clear water drains before installing new again.

Our compact tractor Coolgard II:

 

[ripcord]

I would just drive it as is for a month or two and re-evaluate. You might just be seeing some residual gunk that was hiding under the cap gaskets.

 

[ripcord]

Also, when you refill a cooling system after flushing, add one half of the system capacity of concentrated coolant and then top off with water. If you premix to 50%, you get a 50/50 mix combined with whatever water is left in the block and wind up with significantly less than a 50/50 concentration.

 

[Trav]

1996 Dodge Ram Cummins 5.9 turbo diesel.

Had some kind of green, loooked clean and good. Flushed out with water, ran it to temp, flushed a few more times to clear water.

Installed four gallons of 50/50 mix of distilled water and JD Cool Gard II. It’s a beautiful yellow color.

But when I remove the radiator cap, terribly murky drips come off. Seems somewhat murky in the radiator too.

I drained the radiator and replaced both hoses. I didn’t pull a block drain, but installed 16 of 26 quarts.

The best example is what dropped off the cap.

Thing with the cap is that I washed it. So if it was additive clash, there’s not much additive on the cap to clash. And the thing with the radiator is that it did this before turning the engine on. So it’s not like it’s gone through a number of heating cycles. Water flushed through was clear, so I don’t think there was a lot of remnant residue there.

I’m not opposed to driving a bit and then replacing again. Not a fan of it, but it seems like best practice. But any thoughts on this mess?

View attachment 27520View attachment 27521

Converting from one coolant to another is always a PITA, I usually pop the T stat and heater hoses and flush it all through. Drive it a while then do another flush out (citric acid maybe) and refill.

 

[JHZR2]

I would just drive it as is for a month or two and re-evaluate. You might just be seeing some residual gunk that was hiding under the cap gaskets.

I do think this may be the case. At least to some extent. I washed the cap, but it may not have been enough.

Probably has gunk clinging to the surfaces that the water rinse did not address. I would be inclined to use some type of mild off the shelf cleaner in the system and then many multiple clear water drains before installing new again.

Our compact tractor Coolgard II:
View attachment 27522

I used Prestone flush with fresh water, and got the truck to temperature. I did many clear water drains after that.

 

[dlundblad]

If you didn’t pull the drain plugs on the block, it still has small amounts of the original coolant and the Prestone flush.

As Trav said, changing coolant types is a huge pain.

 

[JHZR2]

It seems to be clearer now, for better or worse. Ill probably drain and refill the radiator sometime over the next week, as that will remove more of the old that is blended in, and get the new stuff in. I have at least two gallons of mix at the ready...

 

[#18FAN]

Just serviced my JD 2520 Cool-Gard II did drain and fill old looked real good just years on it it is a nice golden color now.