sherman power digger 54B

I have a hydraulic leak at the control valve plunger, I removed and I didn't see any type of O rings seals on any of the plungers
there's a couple check valves located on the inside along with springs does anyone have any ideas?
sending a couple pics
Thanks in advance

There is a service manual on the site I gave you the link to the other day. Checking to see that things are clean, not broken, screwed together tight, and the few seals used are in place are about the only services you can do; the manual describes how to do this for various sub-assemblies.

If your control valve matches the book, there is one seal for each spool at the top (control lever end) of the spool, a gasket for the cap on the lower end and an O-ring at each end of the plunger where the plunger eye and plunger cap screw into the plunger (spool). Beyond that all seal points are made by metal-to-metal contact of the components. Given the looks of the spool (plunger) in your picture I would expect similar conditions in the valve housing bore which could allow some leakage and drifting. The plunger sealing in the valve bore is strictly done by the close tolerances of the metal parts. Over time wear and corrosion can increase those clearances. If those conditions are beyond what you can live with, the only true fix is to replace the entire valve.

If you want to see a clearer breakdown of the plunger parts, look at the 54C parts book. The six plunger valve for the 54C is similar, other than they added two spools for the stabilizers (outriggers) and did away with the diverter valve that is used to operate them on the 54B.

This post was edited by Jim.ME on 03/05/2022 at 04:45 am.

Are there O rings in each end of the valve bore ID? Some valves place the seals there instead of on the spool valve.

Okay Ill check it out thanks, Ill double check on the oil seal but first glance I didnt see anything not even o ring

No O Rings on any of the plungers

(reply to post at 05:47:54 03/05/22)

Click to expand...

Thanks for the information I didn't realize that was a seal as far as the o rings there aren't any unless they deteriorated over time,
now I have to locate where to purchase

I would suggest you download those manuals, print them off, and keep them for reference.