I don't know what the "official" Kubota method of doing it is, but I do know what your options are:
One way is to take the hydraulic pressure from the power beyond on the loader valve and run it to a quick-disconnect at the back. Then you need another line coming back to tank, which can tee into another tank line. This has the disadvantage of reducing your flow to the backhoe to less than the full output of the pump, if there's any reduction of plumbing size in the loader valve (and there usually is).
A second way is to run a hose from the pump to a quick-disconnect at the back, then back to the front and into the hose originally going from the front to the distribution block. This has the advantage of sending full pump output to the backhoe, but has the disadvantage of requiring you to connect the two hoses together when you don't have the backhoe attached and all the tractor's implement hydraulic flow is contantly going to the back of the tractor before it gets to the loader. This isn't a problem if you use big hose, but you have to be careful where you route it: You don't want to risk damaging it, and you don't want it where a leak could spray you with hot oil. It also has the disadvantage of requiring that you cut the tractor off to connect and disconnect the hydraulic hoses to and from the backhoe.
A third way, my preference, is a little complicated to explain, but works extremely well. You put two tees separated by a manual needle valve (in my case, 15 gpm) into the pressure line coming out of the pump. I used tees and a needle valve bigger than the line coming from the pump to reduce flow restriction. The tee closest to the pump has the pressure line going to the backhoe coming out of it and the tee farthest from the pump has the return line coming back on it. Both lines terminate in quick-disconnects at the back of the tractor. When the needle valve is open, the hydraulic flow goes straight through both tees and the needle valve as though they weren't even there, so the circuit is identical to what it was before you installed them. When the needle valve is closed, flow is diverted through the hose on the leg of the first tee, to the back, through the quick disconnect, through the backhoe hydraulics, back in the return hose through its quick-disconnect, back into the second tee via the hose on it's leg, and on through the rest of the tractor's standard hydraulic circuit. To use it, you just back up to the backhoe, connect it to the tractor's hydraulics via the quick-disconnects, and close the needle valve. Now the backhoe's hydraulics are "hot" and can be used to help you mount it. When you're done, just unmount the backhoe, open the needle valve, disconnect the two hydraulic hoses going to the backhoe, and drive off. No muss, no fuss.
And, lastly, of course, there's the self-contained backhoe hydraulic system with its own reservoir and a PTO pump.
Does that help? (Sorry I couldn't do it in three words or less.)
Mark
