2015 Cascadia coolant filter change.

Filter should have shut offs on both sides, for changing filter, put them on the block, before the hose. That way, if you blow a hose, they can be closed, isolating the filter, till you fix the hose.

 

Final Charge coolant seems to be pretty good, decent price. Tractor Supply, some Dealers. Pre mix readily available. I’m told pure is also available, at a cheaper price. Mixed 50/50 with distilled water, you can save a few bucks. Either way, along with a pre charged additive on demand filter, which has layers of additive, sandwich between thin layers of sacrificial metal, as a cheap insurance against corrosion/ pitting. Otherwise, add required amount of pencool or equivalent fleet guard additives and test with test strips. Keep it in the proper range. Cheap insurance, avoids a premature overhaul from pitted liner, or blown head gasket.

 

$12 a jug for pre-mixed.

 

Are no shut off valves on The DD series engines For the ones that had a coolant filter. It was a cartridge filter with a spring loaded plunger in the bottom to shut off flow when filter removed.
From past experience if coolant filter was plugged up and slimy. You will be doing a coolant pump soon. Easy to change not a big deal. Change the coolant filter every 100k and shouldn’t be a issue any more.
Have you checked the fan clutch to see if it is locking up 100% and not slipping?.
Do a good flush and then thermostats, and clean the radiator fins and other heat exchangers as well.