I just bought a used Duerr log splitter. It runs great, (thanks to my brother), but is low on hydraulic fluid. I can find absolutely nothing on the web about this company. I know they were headquartered in Spokane Washington, but apparently, they are long gone. I need to know what to use for hydraulic fluid in this thing. I've been told that 30 weight is what it needs, (although it sure smells like hydraulic is in it), and some say that only hydraulic may be used in it. Any ideas?

I believe Duerr is now owned by MTD. Although I still see Duerr still being sold.

30wt is to heavy i'm sure! All though we did use 10wt in some hyd systems in place of "cherry juice"(hydraulic) when I was in the ARMY.

Once I thought about it, 30 weight oil would be way to thick, especially when cold. Looks like hydraulic oil for this application. I'm still unable to find anything about Duerr on the web though. Thanks for the replies.