Is this jack release valve replaceable?

[atikovi]

8 ton long ram jack in an engine crane. The release valve has been so stiff that I can't turn it with the handle and have to use a crescent wrench. Today I broke off one side of the release valve and relied on the other, but that will probably break off soon too.

 

[PCustoms]

Can't tell from the pic but isn't that just a roll pin through a threaded "plug"?

Unscrew the plug (oil will drain), de-gunk or otherwise fix why it's stiff, put a new roll pin in it and re-install

 

[finn]

I broke one years ago and got tired of using vice grips, so, in the heat of battle, I grabbed the nearest fastener around, which happened to be a box nail, and mig welded it to the stub as a temporary repair.

The plan was to do a permanent repair when I finished that job, but it’s been fifteen or more years now and the nail is still there.

Wish I had grabbed a bigger nail, though.