FEL Power beyond w/o return to tank line (only two hoses)???

[jas67]

My '98 Kubota B7100HST has a Woods DuAl 145 front end loader that I assume was installed by Messick's (the tractor has Messick's stickers on it).

There are only two hydraulic lines to the loader, both connected to the hydraulic block that is inline with the hard hydraulic pressure line that feeds the 3pt hitch. This setup is functioning like a power beyond setup, as the 3pt hitch gets it pressure feed from the return line of the loader.

I'm in the process of adding rear remotes, so I've been reading up on how to set up power beyond valves, and have learned that you need a low pressure line return back to the tank from the "Out" port, in addition to the power beyond port, which feeds the next item in the series hydraulic circuit, which in my case is the 3pt hitch.

I was going to try to connect the valve for my rear remotes the same way, but didn't know what to do with the extra port? Plug the power beyond, and use the out port, or what, so i called the tech support at Surplus Center, where I purchased my block. They informed me that if I did that, I would blow seals in the valve with back pressure from the 3pt when I use the 3pt.

Sooooo, my question, is why hasn't this happened with my loader valve, and should I be concerned?

Thanks,
Jay

 

[3RRL]

My '98 Kubota B7100HST has a Woods DuAl 145 front end loader that I assume was installed by Messick's (the tractor has Messick's stickers on it).

There are only two hydraulic lines to the loader, both connected to the hydraulic block that is inline with the hard hydraulic pressure line that feeds the 3pt hitch. This setup is functioning like a power beyond setup, as the 3pt hitch gets it pressure feed from the return line of the loader.

I'm in the process of adding rear remotes, so I've been reading up on how to set up power beyond valves, and have learned that you need a low pressure line return back to the tank from the "Out" port, in addition to the power beyond port, which feeds the next item in the series hydraulic circuit, which in my case is the 3pt hitch.

I was going to try to connect the valve for my rear remotes the same way, but didn't know what to do with the extra port? Plug the power beyond, and use the out port, or what, so i called the tech support at Surplus Center, where I purchased my block. They informed me that if I did that, I would blow seals in the valve with back pressure from the 3pt when I use the 3pt.

Sooooo, my question, is why hasn't this happened with my loader valve, and should I be concerned?

Thanks,
Jay

Jay,
They are right about that and it can happen.
The best way to feed other valves in the system is to use power beyond and a separate return to sump line (low pressure). It prevents what they are talking about. Although there are loader valves that don't have power beyond and feed the 3pt with the return line, it is not the best way to do it. My Chinese tractor came that way and I switched the FEL valve for one that has power beyond.

I'm not exactly clear from your description of the block how your system is plumbed? I guessing here ... that your FEL is getting it's pressure line from the hydraulic pump, right? And you are saying your new remote valve has power beyond on it?
If so, and it's working for you, what I'd do is:
- you leave the connection alone from the loader valve to the 3pt.
- run the pressure line from the hydraulic pump directly to your new remote valve.
- use the power beyond from your new valve to feed your loader valve.
- run the return line from your new valve back into the hydraulic tank (sump).
- you may need to find a port that goes into your hydraulic tank to do this or add one.

The reason I chose that route is because I'm assuming your FEL valve is being fed directly from the hydraulic pump. Using the power beyond from your new rear remote valve will be just like getting pressure directly from the pump, and you haven't disturbed the way your 3pt is being fed from the loader valve (which works now).
Rob-

 

[jas67]

Jay,
They are right about that and it can happen.
The best way to feed other valves in the system is to use power beyond and a separate return to sump line (low pressure). It prevents what they are talking about. Although there are loader valves that don't have power beyond and feed the 3pt with the return line, it is not the best way to do it. My Chinese tractor came that way and I switched the FEL valve for one that has power beyond.

I'm not exactly clear from your description of the block how your system is plumbed? I guessing here ... that your FEL is getting it's pressure line from the hydraulic pump, right? And you are saying your new remote valve has power beyond on it?
If so, and it's working for you, what I'd do is:
- you leave the connection alone from the loader valve to the 3pt.
- run the pressure line from the hydraulic pump directly to your new remote valve.
- use the power beyond from your new valve to feed your loader valve.
- run the return line from your new valve back into the hydraulic tank (sump).
- you may need to find a port that goes into your hydraulic tank to do this or add one.

The reason I chose that route is because I'm assuming your FEL valve is being fed directly from the hydraulic pump. Using the power beyond from your new rear remote valve will be just like getting pressure directly from the pump, and you haven't disturbed the way your 3pt is being fed from the loader valve (which works now).
Rob-

This is exactly my plan. I just bought what I need today to add the sump connection for the tank connection on my power beyond valve for the remotes.