I have a 20 ton, 5 hp duerr vertical log processor which is over 20 years old, and the directional control valve is not operating properly in the down (splitting) direction. It doesn't stop travel when you release the handle. Do I need to replace the entire valve assembly, or are there O-rings I can replace on the shaft attached to the handle.

When you let go of the handle when splitting does it pop up like it used to, mine pops up.

Log Splitter You can resolve your question here.