I'm still on the fence about the F-350 I'm looking at. The current owner says the oil has about 1500 miles on it. when I asked him about the coolant, he didn't know. With the amount of oil in these beasts, I may let the oil slide but I always change the coolant when I get a vehicle so I know when it was done.

I do remember from my previous F-250 that the chemical PH needs to be right to avoid porosity problems. What does the collective use as far as brand and type of coolant?

 

I use green coolant with Ford diesel cooling system additive. Seems to be a little controversy on coolant types and cup sealant. Figured I would play it safe and use what came with the truck. There are quite a few other people more informed with more experienced so I would wait for them to give their thoughts.

 

Fleetcharge here. Preloaded with SCAs.

 

This is what I used. Just make sure on the rear of the container it states that our year of powerstroke applies. This stuff is not cheap. There may be cheaper stuff out there.

 

I use full strength green, gallons of distilled water and use ford diesel fluid additive SCA.

good time to check radiator fluid for oil or fuel contaminants. I saw little bit of oil in reservoir. So I ended up changing oil cooler o-rings during this process too.

drained radiator, reservoir, pulled driver and passenger block plugs. Pulled thermostat. Put thermostat housing back on, without stat. Flushed with garden hose few times through heater core and reverse flushed. Then flushed with distilled water last to make sure all the hose water was out. I did each few times and a drive cycle with heater on between flushes until warmed up. With each flush I drained from hoses and block. Drained engine oil and replaced oil cooler o-rings. Tried to clean coolant reservoir but it was faded and yellow, so I purchased a new and painted it leaving a section unpainted to see coolant level. Flushed it until it was visibly clean in a cup.

installed new stock thermostat, new oil filter/fresh oil. Fresh fuel filter in the bowl. refilled 50/50 mix of green and distilled plus added recommended amount of additive. Ran her for a while and checked coolant ph and looked for oil residue again. Everything checked out good.

it was a long process ( took me a weekend, especially waiting for cool down between heat cycles) but when I purchased my truck I changed all fluids. They are the bloodline of your truck and you can see what’s been running through the system. Wanted to it once and to the best of my abilities.

 

It's a moot point now. The guy wanted me to trade my '96 Ram 1500 4X4 title for title. I just did an upper engine overhaul on it last summer. I wouldn't take less than $7000 for it if I sold it. He sold the F-350 for $2500, so I guess I dodged a bullet there. My truck runs and drives like a new one, it's just too light for towing the loads I want to pull.