Hydraulic connection to the backhoe

[mikeh19d]

*Cross Posted from LS Tractor* Hello, I have a 2018 XG3025H with FEL & backhoe. I just purchased a grapple for it and I need to plumb in the hydraulics for it. I was wondering if I can use the connections coming off the tractor that are used for my backhoe to control the grapple. Is this connection to the backhoe considered the "power beyond" connection? If so, can I use a log splitter valve to control the opening and closing of the grapple? I would like to keep the cost down as much as possible. I'll take any recommendations you have. Thanks.

 

[ericm979]

I think your LS has a backhoe "loop" like my Branson, where you disconnect male and female quick connects and plug them into the backhoe. You can use that to run a different spool valve that you could use to run the grapple. But if you plan to pick up anything with the 3pt hitch while the grapple valve is connected, you need to find a valve whose tank port can withstand the full system pressure (somewhere around 2500 psi). Most valves's tank ports are rated to 500 or 750 psi. You could damage one of those valves if you lifted something on the 3pt with the valve connected. It can be hard to find the spec on the tank port. Usually its on the manufacturer's spec sheet.

The detent feature on the log splitter valve does not go well with a grapple. A regular single spool valve is $50-100. Fittings and hoses to connect any valve and run lines and quick connects to the loader will run you about $200.

 

[mikeh19d]

You are correct regarding the "loop" connection. You make a good point for not using the log splitter valve. I'll look at picking up a single spool valve, fittings and hoses. I have a couple of questions, where would the placement of the spool valve be in the circuit? If I use a single spool valve, will the backhoe connection still be available when I'm not using the grapple?

 

[ericm979]

My tractor has two factory remotes, a dealer added remote mounted on the fender, and a BH loop. The system goes in this order: pump, loader, dealer remote, BH loop, factory remotes (valves mounted on the transmission and flow directly into the 3pt), 3pt, tank. A lot of that is driven by how easily it is to make the connections.

That stuff I wrote about the T port on your new valve being rated for system pressure is for connecting it through the BH loop. Normal valves have one input, two work ports and two outputs. One output is power beyond, which goes to the next valve in the series. The other is the T port which goes to the tank. If you're using a valve without a PB so the T port takes all the output, the T port has to be able to handle the pressure caused by a valve farther down the line opening it's work ports and doing work.

With either a four port or five port valve you can put it anywhere in the chain. Usually it would go between the loader valve and the 3pt, because the PB and T ports on the 3pt are inside the transmission case where you can't get to them (and the 3pt valve is probably not going to handle the pressure of a valve after it). And having the loader first means it has priority, which is probably what you want. In practice it's often tough to get two things to operate at the same time with our simple hydraulic systems.