Backhoe Rear Hydraulics or Power Beyond Tap for Woods Backhoe on CT230

[DaveK OR]

One issue has come up with regard to the hydraulics for my Woods backhoe. That is, should I use the rear hydraulic A-B ports, or go to the trouble of tapping into the power-beyond and plumbing a separate return.

In reading the instructions for the Bobcat (Rhino-built) backhoe, Bobcat recommended (requires?) using the rear hydraulic A-B ports. On the other hand, Woods recommends separate, dedicated supply and return lines. I installed the rear hydraulic kit specifically because I eventually wanted to add the backhoe, so it will be very frustrating to have to add additional plumbing at this point.

So, a few questions:

1) If I use the A-B ports, I can see a potential for having reverse flow to the backhoe hydraulics. This would occur either by reversing the supply lines, or putting the A-B control lever in the wrong position. I understand that the backhoe would not operate with reverse flow, but would such a mistake actually damage the backhoe hydraulics?

2) Does the A-B control valve operate with an "open return" on either line? That is, whichever line is being supplied with pressure, the other provides no significant resistance to the return flow. Also, when the A-B lever is in the "neutral" position, do both lines provide that open return?

3) Is there a difference between the Woods and Bobcat backhoe hydraulic controls, such that it makes a difference in how hydraulic flow is supplied to the backhoe?

4) Anything else I should consider about my hydraulic hookup decision?​

 

[MtnViewRanch]

Dave, no good reason to not just use your A-B couplers. They flow 12 GPM and that is far more than what your tractor puts out.

No damage is going to occur if you pull the control lever the wrong way to supply the hoe. Things just won't work properly.

When fluid flows in one port, it flows out the other, the fluid has to go some where.

When the lever is in the center (neutral) all ports are closed on YOUR control valve.

Plug it in and go to work. :thumbsup:

 

[DaveK OR]

Thanks! I figured it would be that way, but the Woods rep was pretty inflexible in his "recommendations," and implied that I could damage the control valve block with reverse flow or back-pressure.

 

[RickB]

Reverse flow through the backhoe valve can and does easily damage the spool seals. Installation of a check valve in one of the hoses will prevent problems. I use my remote valve to power my Woods hoe.

 

[MtnViewRanch]

Reverse flow through the backhoe valve can and does easily damage the spool seals. Installation of a check valve in one of the hoses will prevent problems. I use my remote valve to power my Woods hoe.

All the valves that I have ever taken apart have never had a seal that would be damaged by reverse flow put to the valve. The valve simply would not work properly is all.

But then there are many different valves out there and I have only seen a few.

 

[DaveK OR]

The check-valve is an easy preventative measure, so I'll see about adding that into the system to prevent even the remote possibility of damage from a reverse flow situation. Thanks for that idea!

I'm working on the subframe installation today, taking notes and pix along the way (slower, but may help somebody else down the road). I'll post those in my other thread.

 

[RickB]

All the valves that I have ever taken apart have never had a seal that would be damaged by reverse flow put to the valve. The valve simply would not work properly is all.

But then there are many different valves out there and I have only seen a few.

Return oil is typically ported towards the spool ends. When this galley is subjected to system pressure, instant failure of the spool seals is the result. Usually 2 times however many spools are in the stack. I've seen it too many times. Reverse flow will do this, as will powering another valve downstream by plumbing the return to the next valve's input rather than using a power beyond circuit.

 

[tman1020]

Is there any concern of deadheading the pump with the use of check valves in this application?
Also for further info i believe kioti has a optional hydraulic return line kit for there backhoe that dumps return oil into vent/fill tube. As I understand it it was designed to reduce heat buildup in extended use of there backhoe. I'm wondering if this will alleviate the risks that you mentioned and still allow use of your rear remote.

 

[RickB]

Is there any concern of deadheading the pump with the use of check valves in this application?

There's always concern when any hydraulic pump is deadheaded. The trick is to be smart enough to know it is happening and not let it happen for more than a few seconds. That's not going to hurt anything.
When you activate a circuit and nothing happens, figure out why.

 

[countrybumpkin]

The check valve would defiantly be a fool proof way of not letting pressure go the wrong way. Also you can mark one of the hose ends with a colored plastic wire tie, and also the same color wire tie around the remote connection on the tractor, and a colored dot or something on the panel next to the control lever. This just helps keep everything the same every time you hook up.