I got some attachments that have a smaller third hose. I think this is for case drain. I don't have an installed third line on my machine. Can I just run that line back to the hydraulic tank and dump it in the top? I saw some direction that says it would be better to have it dump in below the top level of oil to minimize foaming. How much flow is it really going to have? Quite a bit or just a dribble? My hydraulic tank fill has a grate in the neck that makes filling it with fluid REAL slow. I have to pour about a pencil size stream of fluid when it needs more oil. Is the case drain going to have more flow than that?
On my machine the auxiliary return line (case drain) returns to a fitting on the hydraulic filter housing, which is mounted in tank. Helps keep out unwanted debris.
What is your machine?
ASV, My pilot control returns, come in at bottom of tank. And main return line comes into filter housing. I believe if there's not a lot of internal,, leakage in what ever hydraulic motor your running, there should be, a pencil lead, size stream of return oil. I know when you get foam in a power steering reservoir, that pump whines like a b---ch. I wouldn't take that chance personally.