Coolant Color Guide and Cummins Engineering Standard (CES) 14439 Approved

[Zeb Severson]

I just had a situation where I needed to add some coolant and I was changing the coolant filter. My 2003 ISL 400 CM554 needs coolant meeting Cummins Engineering Standard (CES) 14439 to prevent cavitation. Cummins support mentioned earlier years cavitation was a bigger issue than newer engines. My issue was my coolant looked newer and was likely changed a year or two before I bought the coach in 2024, so I didn't want to change coolant not to mention the hassle. But, the color was green and I wanted to stick with green to monitor the condition of the system and not mix up types of coolant. Cummins sent me a list of approved coolants and only a few were green in color. For what it is worth I'm sharing in case it is helpful for anyone in the future.

[Steve Huber]

Zeb,
FWIW you may want to have a coolant analysis done since green is the color of Prestone automotive coolant. Mixing coolants can lead to cavitation and foaming. IMHO it would pay to have it done unless you are 100% sure the PO used the same coolant as you added.
Steve

[Eric Maclean Co-Admin]

Zeb
I have to agree with Steve here. .
Over the last 25+ years almost all automotive ethylene glycol has been green until recently when Dex cool and others arrived on the seen,the green stuff is cheaper than the diesel formulations and is approved for Virgin block engines ( those where the cylinder bores are bored directly into the casting not wet sleeved)
The biggest difference is that the coolants formulated for heavy diesel engines contain more additives designed to keep the coolant from cavitation around the wet sleeve caused by vibration.
This cavitation becomes a problem in a wet sleeved engine as it can and will erode the cylinder sleeves and even the block where the sleeve O rings seal
Causing these O rings to leak coolant into the crank case or even cavitate though the sleeve walls into the combustion chamber .

Even in diesel coolants with all the good additives packages for cavitation, rust inhibitor, etc. their effectiveness diminishes with time and usage .
Cummins as well as may other sources manufacturer test strips to measure the levels of these additives in the coolant .
There are also additive supplements to help maintain or boost the levels for longer life of the coolant package.

But in the end there are some coolants that are not compatible with each other and can create problems like gelling of the coolant there fore its best to start out knowing what coolant is in the system and stay with it.

https://www.amazon.ca/Fleetguard-CC2602-Coolant-3-Way-bottle/dp/B01CPU734S/ref=asc_df_B01CPU734S?mcid=02c65bf8fc10318ea0b347c5bec84f10&tag=googleshopc0c-20&linkCode=df0&hvadid=706745692750&hvpos=&hvnetw=g&hvrand=12063193660518881228&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=9000653&hvtargid=pla-911646373560&psc=1&gad_source=1

https://www.amazon.ca/Cummins-Filtration-Fleetguard-Coolant-Additive/dp/B084Z16VD4

Hope this helps
Eric