The older case machines probably won't have brakes that work, my dozer never had brakes till I finally took the time to fix them and get them working again, its not a big deal, just something to remember, especially when it comes to loading and unloading the machine on trailers.
![case 850 dozer case 850 dozer](https://bigiron.blob.core.windows.net/public/items/005928831904e51180c300155d70caf6/case850trackdozer-2.jpg)
Not sure how much you've run a dozer, but once you get onto this you'll do just fine. The case dozers have what some call two speed steering, or both tracks are under power as you turn, instead of stopping one track to turn, once you get onto this, its the biggest thing ever, verses say cat machines of the same age, those require a track to stop in order to turn the dozer. I've never seen one with an outside 8 way on it before, only four way blades or six way blades, I've also never run an 8 way before very much, a six way is unbeatable on those machines, about the handiest size dozer on the market. As for the hydraulic oil, use the cheaper hytran, those dozers are pretty descent machines to run, really simple and still get something done at the end of the day.
![case 850 dozer case 850 dozer](https://st.mascus.com/imagetilewm/product/11b91bc3/case-850-m-lt,8a158ca9.jpg)
The single biggest thing, is no matter what anyone tells you if the clutches in that machine are wet clutches and not dry, the torque and transmission require TCH oil in them, hytran is not a substitution for TCH on the case dozers, hytran will eat up the clutch linings on those machines and it gets expensive, most local dealers will tell you hytran is safe to use, its not.