Community Forums

Lv2Roam2 · 05-11-2023, 06:22 AM

My coach has used fully-formulated coolant (SCA pre-charged) since day one. Have been using Alliance FF from Freightliner for flushes and top-offs. That coolant is getting harder to find.
A Freightliner dealer recommended changing to Alliance OAT extended life coolant. Somewhere in the cobwebs of my memories I remember these as being incompatible and the Alliance comparability chart seems to indicate the same (though somewhat difficult to interpret).

Appreciate thoughts and recommendations. TIA!!

Lv2Roam2 · 05-11-2023, 08:06 AM

UPDATE: Gaffney Freightliner Service Center folks have replied: We do not recommend using the OAT in place of the SCA as it is not compatible with our coolant sensors.

Well ... feel like I'm stuck in the middle. Appreciate hearing other thoughts but meanwhile going to stick with the Freightliner Service Center recommendation - and keep all the documentation.

153stars · 05-11-2023, 06:09 PM

Its to organic acid that attacks the sensors.
Other brand SCA coolants should be fine to run. There are non OAT high mileage coolants with DCA4. The DCA4 additive types with molybdenum and nitrate gives slightly wider band of protection on test charts. Too high of nitrates is not ideal the mix helps keep it lower as well. I think it would now actually be hard to find nitrate only coolants.
Cummins says no adverse reactions even between different coolants. Not saying to mix OAT and SCA to run indefinitely as you can't really test partial SCA levels remaining.

153stars · 05-12-2023, 07:21 AM

I forgot to add how often are you needing flushed. The test strips and pre-charged filter should keep you in spec. J&G oil testing can check all aspects of the coolants protection package and contaminants ,so not to change more than necessary.
The OAT is extended mileage but newer SCA coolants and other antifreeze have also been improved over the years as well.
Color of coolant you chose is an additive but you really don't want to mix Texaco red with a green AT and end up with brown coolant. Maybe why some Auto global AF makers chose yellow.