Backhoe hydraulic plumbing

[BJN644]

Getting ready to pull the trigger on a new Woods BH80X for the CK35. I'm doing the install myself, I have a set of rear remotes on my tractor, but after talking with Woods tech support they recommend running the return line directly into the transmission case to eliminated any restriction going through the quick coupler. My question is, I'm pretty sure I have seen a picture of this setup on this site before, I just can't find it. Is there a Kioti part for this return line set up ? or does anyone have a picture they could post?

[MichiganIron]

The KIOTI KB24XX Backhoe's are supplied with a kit that allows plumbing through the Quick Connects or an option to plumb directly to tank. The plumb to tank actually goes to the rear transmission oil fill port. Your dealer probably has the fittings and breather for a direct return set up.

We always set up our backhoes to the quick connects. It's a cleaner set up and does not cause any operational problems with the backhoe. It also allows an you to accidentally bump the rear remote lever in the wrong direction without dead-heading the hydraulic system. That alone is reason enough for us to plumb to the quick connects.

[dfkrug]

....Woods tech support they recommend running the return line directly into the transmission case to eliminated any restriction going through the quick coupler.

I think dumping the return to the tank is better than to the AUX valve, but
you will still have a QD fitting to go thru. The reason to do it is that
there are restrictions inside the AUX valve itself.

Better yet is to avoid the AUX valve entirely and use the power beyond
circuit.

My CK30 uses the AUX valve for IN and OUT and it works fine, but I think
I can reduce the fluid heating by making one or both of the above changes.
Not high on my list at present.

[Steve_Miller]

I assume that the lines and valves are sized to suit the oil flows that are supplied by that tractor. The only problem I see is if someone downsized something (ie...lines, connectors valves) that were connected to the aux port would be possibly overheating the fluid because of back pressure and then oil being dumped over the relief constantly. My two cents worth.

Steve

[BJN644]

Thanks to all that replied.
I would like to use a dedicated hydraulic circuit other than the aux remotes, just not sure how to do that. The Woods hyd kit bolts on the transmission in the same place that the Kioti remote valve block goes. I don't want to eliminate that and I don't think you can piggy back the 2, if you could that's what I would do. As stated before I think I'll do what Woods recommended and return directly to the tank if I can get the right fittings. If anyone has any ideas or picture of tapping into the hydraulic circuit another way I'd be interested.
On an interesting note, while hoe shopping, a dealer that sells the other orange tractor was vehemently opposed to plumbing through the remotes and said that they have had people damage their tractors hyd system by doing this. I have seen several Kioti's run this way and figured thats why the valve has a detent in it, maybe the botas are different?

[MichiganIron]

The return line is low pressure, and does generate much heat through the quick-connects. The heat is generated through the supply side quick connects at the restriction. This no different that the loader, except the loader uses 3/8" couplers, the backhoes use 1/2". If you are really concerned about heat, use the auxiliary valve plugs and change them to 3/4" Flat face couplers. This will reduce any concern for restrictions.

[dfkrug]

I would like to use a dedicated hydraulic circuit other than the aux remotes, just not sure how to do that. The Woods hyd kit bolts on the transmission in the same place that the Kioti remote valve block goes. I don't want to eliminate that and I don't think you can piggy back the 2, if you could that's what I would do. As stated before I think I'll do what Woods recommended and return directly to the tank if I can get the right fittings.

I have given this a lot of thought, and can hit on the highlights thus:

Your tractor's implement pump supplies the FEL valve, then the AUX
valve(s), then the 3PH valve. The last valve (3PH) dumps to the tank.
Most CUTs do it this way.

When the hoe is mounted, you can do without the 3PH, but must have
the FEL. You may or may not want to do without the AUX valve(s),
depending on if you use it for a hyd thumb, or a grapple on the FEL bkt.

Your hoe valve has no Power Beyond outlet like your FEL and AUX valves
have, so it must be last in the circuit if it is plumbed as a primary valve
in the power beyond pressure circuit. As I said earlier, the best way to
plumb a hoe is as a primary valve in the PB circuit.

Kioti gets around this problem by providing detented work ports on its
AUX valve, and they tell hoe users to connect there. It is a clean and
easy installation, but somewhat of a compromise. If you look at the
Kioti AUX valve, you can see internally that the passages are not large,
certainly smaller than the ID of a 1/2" hose. That (in addition to some
restriction from the high pressure QD fitting) causes some significant
restrictions to hydraulic flow. As I said before, this setup does work, but
I have installed and used the same hoe extensively on tractors that I
have connected to the PB out of the FEL valve, and to the PB Out of
the AUX valve and I got less oil heating.

Note that Kioti does not use QDs between the IN of FEL valve and the
pump, and none between the other valves either. On some Kubotas, the
FEL is connected to the loader, so the IN and PB OUT do have QDs, but
large ones (1/2").

Now, back to the M27 tractors, including yours and mine. The ideal place
to put a hoe is with the hoe's IN after the AUX valve, and the hoe's Out
connected to the tank. The 3PH is bypassed when the hoe is mounted.
Large QDs should be used...I use 1/2" QDs and 3/4" hoses between the
AUX and 3PH, which are connected to each other when the hoe is not
mounted. The problem is, the CK does not use external plumbing between
the AUX and 3PH, so it is hard to get access to the PB Out on the AUX.

Woods may get around this by providing a manifold that connects to the
same place as the AUX valve does. If so, I would like to see a photo
and testimonial from a user. Does it keep you from using the Kioti OEM
AUX valve, or is it stacked on (to the right or left) of the OEM AUX valve?

So, the 2nd best place to put the hoe is connected to the PB Out of the
FEL valve, with hoe Out connected to the tank. (Kioti and Kubota do not
provide many unused ports for the hoe Out, so I have purchased the oil fill
port adapters.) Kioti does have a hardline between the two valves, so you
would need to remove it and adapt it to a large QD and hoses for your
hoe. I am considering this for my CK.

Note that I have chosen to use electric solenoid diverters for my hyd
thumb and 4n1 bkt partially wanting to avoid use of the AUX valve in case
I bypass it in the future. I leave my hoe mounted all the time, but I
turn the AUX valve Off when not using it.

If you decide to do it this way, consult your manual for which line is
which on your FEL valve underneath, or just follow them from the valve.
Accessibility is good.

[dfkrug]

The return line is low pressure, and does generate much heat through the quick-connects. The heat is generated through the supply side quick connects at the restriction.

I agree that the return side low pressure lines and fittings do not cause
the greater heat generation. The inside passages of the AUX valve are
quite small, and that is where a lot of the heat comes from. When I add
aftermarket AUX valves, I go with larger units.

[MichiganIron]

Here is a diagram of the KIOTI KB Series direct return to tank system.Rear Remote to Tank.pdf

[BJN644]

Just what I was talking about thanks.
I still like the idea of piggy backing the Woods hydraulic kit with the Kioti aux valve best, I need to research that option more.