Can my PHD Power Down cylinder do Double Duty ?

[sparc]

My JD PHD200 has the power down option.

I was looking at it today and thinking I will not use the PHD that often, at least not as often as I will use the 3ph for other attachments.

I was looking at that hydraulic cylinder and my top link and thinking they are about the same length and have about the same adjustment range.

I checked and the pin sizes are the same.

So it looks like if I added a third hose with the correct quick connect I could use this cylinder as a hydraulic top link and when I need it on the PHD I can transfer it over there and use it for drilling holes.

Am I missing something or will this work? Is the seal in the hose which is not connected good for the pressure it will see when not connected? I would want to damage it or have it leak.

The way it works now on the PHD the one hose extends the ram, the second hose is piped to dump back to a common return. When the PHD is raised the down assist cylinder is compressed and the hydraulic fluid id dumped in the return line.

First photo shows the plugged side of the piston where I would put the third hose for use when connected as a hyd. top link.

Second photo shows the relief valve and return line.

Last two photos show the return connection on the tractor and the rear hydraulic connections.

Anyone tried this?

 

[Xfaxman]

Hydraulic top link cylinders do not have a pressure relief valve, but that could be removed.

If that is a plug and not an air vent, I don't understand how the air gets in and out of the retract side of the piston.

Retract the cylinder, remove the plug, put some light weight oil in it, put the plug back in and extend the cylinder all the way. If the oil comes out around the shaft, it won't work for a top link.

If the oil comes through the small holes in the plug, it should work.

You could take the cylinder to a hydraulic repair shop and ask them.

 

[sparc]

Good point. If that is a plug and not a vent (didn't look at it that close) then
the cylinder would be air bound on that side of the piston and not move.

Or, as you say, if it is a plug then there must be no seal on the rod which would
allow air to flow in/out but then dirt would also get in the cylinder where it could
damage the piston seal and cause leakby.

Your test sounds like it will reveal the answers. I'll have to give it a try.

 

[Xfaxman]

Look at the plug first. these are air vent pipe plugs.


Pictures from Google Image Search

 

[sparc]

Looked at it this afternoon. The plug has a small (about 1/16") hole in it not a vent fitting like the examples you show. I was ablable to insert a small wire through the hole for over an inch.

I am familiar with those vent plugs having rebuilt many pneumatic cylinders used to power ventilation dampers, valve actuators, etc.

So it looks like it might be possible to repurpose this. But its not something where you would want to switch back and forth like I had originally suggested. The one side which is currently vented to atmosphere would be filled with hydraulic fluid, and drawing that out and installing the vent would be a mess and time consuming. So it will probably stay where it is and I'll get a hydraulic top link kit.

 

[Xfaxman]

Fit Rite Hydraulics - fitritehydraulics.com

http://www.tractorbynet.com/forums/hydraulics/237950-anyone-bought-fit-rite-hyd.html

 

[sparc]

Yes, I am aware of Brian and Fit Rite.
Thanks.