Stephen Bannasch (316 ppm) on Nostr: There will also be a bit that closes an internal valve so that hydraulic pressure ...

There will also be a bit that closes an internal valve so that hydraulic pressure builds up when you operate the pumping handle. Doing this should cause the splitting mechanism to operate. When that same bit is moved a different way it opens the internal valve and releases pressure in the hydraulic system.

On my floor jack this is a sticking out bit with a slot. I’d expect something easier to operate with a hand on your splitter.