Ford 555b. Unused port on hydraulic Unload Valve

[Chewwy]

While crawling around under my recently aquired Ford 555b, I found what appears to be a missing large plug on the bottom of the unload valve assembly (shown on the parts diagram for unload valve and manifold). I have ordered a replacement plug (1 3/16 - 12 plug, part no. E4NNE846AA) but am curious as to what purpose this unused port serves. Everthing appears to be working ok. My guess is it's for a hydraulic function not used on this model.

Any ideas??

 

[joecdeere]

I'm guessing it's to plug a machining access hole from when the valve body was being made

your parts page - New Holland (555B) - 3 CYL TRACTOR LOADER BACKHOE (6/85-1/88) Parts Diagrams

 

[Chewwy]

I'm guessing it's to plug a machining access hole from when the valve body was being made

your parts page - New Holland (555B) - 3 CYL TRACTOR LOADER BACKHOE (6/85-1�/88) Parts Diagrams

Thanks, JoeCDeere. I hadn't thought of that. Perhaps it serves some purpose in providing access for repair or rebuildong it too.