I just picked up an 843 and am in the process of doing all the maintenance that hasn't been done since 2014 according to the paint stick dates on the filter. When it comes to the hydraulic system, the book states that it has a resevoir capacity of 15.5 qts and a system capacity of 8.25 gals. Is there a way to change out most of that fluid? Or is it accepted practice to just change out what's in the resevoir and call it good? I will be doing both the hydraulic system and hydrostat system filters at the same time. Would it be adviseable to change 4 gals of fluid now then run it for a specific amount of time and change again? Kind of like a partial water change in a fish tank, that's the only way I can see to get more of the dirty fluid out. Also, is there a way to drain the chain case oil as I want to change that as well while I'm updating everything? Or is it the same as the resevoir, hand pump out as much as possible then refill. Thanks. https://photos.app.goo.gl/LY4QUWWCPm6vXgbF6
