Any select o speed experts?

[sony224422]

I am splitting my 4040 industrial and replacing the Sos, and I have a question about the suction on the lower passenger side front. Does that require an o ring? And is that just for the hydraulic pump that’s mounted on the engine? If I don’t have a 3pt or pto, is that necessary to reinstall or is there a block off port? I’m pretty sure my current sos is sucking the fluid out of the transmission because of that line. I will check the rear seals first as I am planning on splitting the tractor from the rear first to see if I can see anything. I lost almost all pressure to the sos after adjusting the bands per the service manual. It never worked correct but something happened after that.

Any other seals or o rings I need to find?