Backhoe & Power Beyond Question

[R_squared]

The basic question is can the power beyond inlet on a tractors hydraulic manifold be used as a return? My tractor has a Prince LVR loader control valve with joystick and power beyond port. My tractor also has a hydraulic manifold block with a power beyond, a pressure outlet and a return inlet. Currently, the power beyond from the Prince LVR is connected to the power beyond on the tractors hydraulic manifold for 3-point lift control. I want to make a bulkhead near the rear remotes that have a pair of quick disconnects and a short jumper hose connecting them. One hose to the bulkhead will be from the Prince LVR power beyond. The hose from the Prince LVR to tractor hydraulic manifold will be discarded. The other hose from the bulkhead will be connected to the tractors hydraulic manifold power beyond. The short jumper hose will be connected to both of the bulkhead mounted quick disconnects when the backhoe is not being used, this completes the loop for 3-point lift control. When you want to use the backhoe you would have to remove the short jumper hose and connect the backhoe inlet and outlet hoses to the bulkhead. The backhoe inlet would connect to the power beyond from the Prince LVR and the backhoe outlet would connect to the tractors hydraulic manifold block power beyond. Is this loop safe to use or does the backhoe outlet have to be teed into the tractors hydraulic manifold block return inlet? The backhoe hose kit is a pain to use. If this loop is doable then you would not have to crawl under the tractor to disconnect the line from the hydraulic manifold block power beyond and connect it to the backhoe inlet and connect the backhoe outlet to the tractors hydraulic manifold block return inlet and visa versa when removing the backhoe. I contacted the manufactures of the related equipment and could not get an answer because each did not want to make comments on the operation of other manufactures equipment. Thanks!

 

[JDeereman]

The basic question is can the power beyond inlet on a tractors hydraulic manifold be used as a return? My tractor has a Prince LVR loader control valve with joystick and power beyond port. My tractor also has a hydraulic manifold block with a power beyond, a pressure outlet and a return inlet. Currently, the power beyond from the Prince LVR is connected to the power beyond on the tractors hydraulic manifold for 3-point lift control. I want to make a bulkhead near the rear remotes that have a pair of quick disconnects and a short jumper hose connecting them. One hose to the bulkhead will be from the Prince LVR power beyond. The hose from the Prince LVR to tractor hydraulic manifold will be discarded. The other hose from the bulkhead will be connected to the tractors hydraulic manifold power beyond. The short jumper hose will be connected to both of the bulkhead mounted quick disconnects when the backhoe is not being used, this completes the loop for 3-point lift control. When you want to use the backhoe you would have to remove the short jumper hose and connect the backhoe inlet and outlet hoses to the bulkhead. The backhoe inlet would connect to the power beyond from the Prince LVR and the backhoe outlet would connect to the tractors hydraulic manifold block power beyond. Is this loop safe to use or does the backhoe outlet have to be teed into the tractors hydraulic manifold block return inlet? The backhoe hose kit is a pain to use. If this loop is doable then you would not have to crawl under the tractor to disconnect the line from the hydraulic manifold block power beyond and connect it to the backhoe inlet and connect the backhoe outlet to the tractors hydraulic manifold block return inlet and visa versa when removing the backhoe. I contacted the manufactures of the related equipment and could not get an answer because each did not want to make comments on the operation of other manufactures equipment. Thanks!

This can be made to work provided no valve downstream of the bh is ever to be used or touched (on purpose or by accident). most bh manufacturers consider this a dangerous setup and would tell you that the bh must exhaust directly to an unblocked (unblockable) return path. this achieves two things for them. no back pressure is ever seen by the bh circuit and no accidental operation of the 3-point is possible.

Theo

 

[kennyd]

I would do it the way JD does on the mid-framed CUT's...That is to add three QD's to the rear instead of two like you suggested. The third is just a hose for the return-to-tank line.
So you would have three connections at the rear:

>PB Out
>PB In (goes to the 3PH)
>RTT Return to tank for backhoe operation.

 

[R_squared]

Thanks guys for your suggestions. I could not find a good description of what exactly happens at the power beyond port on the tractor manifold. Does it have any pressure or flow when the hydraulic system is at idle? Does it have any pressure or flow when the loader valves are activated? Same questions for 3-point operation. I think Ken D, 3 QDs suggestions will work well. You would still use the short jumper hose when the backhoe is off to complete the power beyond loop for the 3-point operation. The good thing is that proper length hoses can be made and they would be permanently routed under the tractor. Also, there would be no QDs under the tractor where they would be more likely to cause contamination. Ill miss crawling on the ground though.

 

[kennyd]

The PB "loop" ALWAYS has fluid flowing through it. When all the valves are in neutral then it's the full flow of the pump, when a valve is activated, then whatever the fluid the valve does not redirect to the work port will continue to flow through the PB loop to the next valve in series.

The three ports at the rear is the best way IMHO. I can post a schematic and possibly pictures of the JD setup if needed.

 

[JDeereman]

Does it have any pressure or flow when the hydraulic system is at idle? Does it have any pressure or flow when the loader valves are activated? Same questions for 3-point operation.

In an open center system with pb there will always be flow through the system at idle but only low residual pressure. once you operate a valve anywhere within the system, pressure builds in the system up to that valve (and through that valve for its particular use). downstream pb flow is effectively shut off (or partially shut off) until the valve is returned to the neutral position again. operating your fel control valve while the bh is in use will interfere with the bh momentarily but cause no harm. the same is not true if operating the 3-point levers in your originally proposed scheme because it would place a sudden back pressure on the bh circuit and potentially bind the 3-point arms to the bh frame or even worse pinch one or more delicate body parts. ouch!

Theo

 

[R_squared]

Ken G no need to post visual aides. The fun is in figuring out all the fittings needed and having the hoses made to your specifications.

Theo Thanks for the better PB pressure and flow explanations.


Guys, I did spend time searching through the archives on the power beyond subject, but the content was weak. Hopefully this thread will help future people understand what goes on with the power beyond.

 

[mgrohman]

Hi, thought I would post on this thread how I did this, for commentary and critique.
I needed to add a rear valve to raise and lower my mower-conditioner, which has a single acting cylinder. I think what I have done is appropriate. I basically had hoses made that Tee into the line that comes out of the 'PB' port on my loader control valve (pointing to it with my knife in the picture; the one I Teed into is to the right of the blade). This line already had a quick-disconnect connection at its midpoint, so I just had my hoses made with the opposite QD's. I purchased a Converta valve at TSC ($122) and converted it to single-acting by installing the supplied plugs (instructions for this are on the outside of the box. The instructions aren't very good, but I called them and got help right away). With this setup you use the work port labeled 'B', and 'A' is plugged.
Although itｴs not pretty (can't believe it rusted in one day!), this all works and works well and got me on the field cutting. The the only downside is the way I have it, the lever works opposite of what you're used to. However the above posts about 'PB return is not being a proper return port' have me worried (my system return is the hose marked with electrical tape in the picture). The lines do get fairly warm, but I'm fairly sure this is normal.

Also worth noting that the valve mfr made sure to mention this valve is not for raising and lowering something that can't drop a touch before it goes up (not an issue for my moco).

 

[kennyd]

Hi, thought I would post on this thread how I did this, for commentary and critique.
I needed to add a rear valve to raise and lower my mower-conditioner, which has a single acting cylinder. I think what I have done is appropriate. I basically had hoses made that Tee into the line that comes out of the 'PB' port on my loader control valve (pointing to it with my knife in the picture; the one I Teed into is to the right of the blade). This line already had a quick-disconnect connection at its midpoint, so I just had my hoses made with the opposite QD's. I purchased a Converta valve at TSC ($122) and converted it to single-acting by installing the supplied plugs (instructions for this are on the outside of the box. The instructions aren't very good, but I called them and got help right away). With this setup you use the work port labeled 'B', and 'A' is plugged.
Although itｴs not pretty (can't believe it rusted in one day!), this all works and works well and got me on the field cutting. The the only downside is the way I have it, the lever works opposite of what you're used to. However the above posts about 'PB return is not being a proper return port' have me worried (my system return is the hose marked with electrical tape in the picture). The lines do get fairly warm, but I'm fairly sure this is normal.

Also worth noting that the valve mfr made sure to mention this valve is not for raising and lowering something that can't drop a touch before it goes up (not an issue for my moco).

Welcome to TBN

I am glad your valve works for you-BUT-in general, you CANNOT "T" into pressure lines on open center hydraulic systems. All new valves must be plumbed in series to work properly. I would guess it's working for you because it is a SA cylinder and does not need a lot of pressure to raise the mower.

 

[mgrohman]

I actually was going to T into the 'In' line until I read your posts warning about that. I guess I thought I was doing the right thing by T'ing into the PB line - not so? So is the way I have it OK except I should have the return (i.e. the 'Out' from my new valve) go somewhere else? I have time to change this now because I'm not cutting hay again until next summer.
Marty