Rear remote on a BX22.....

[RichNJKubota]

Jerry,
Could you explain your diagram? What is "ABC"? How does the fluid flow?
I understand about 50% of it but not the rest.
Thanks,
Rich

 

[JerryG]

It was late when I posted that, I should have changed a few things. Without all of the print, somethings on it are confusing. I will clean it up and repost.

 

[JerryG]

On the left side of the picture. You have the three lines that go to the tractor. The pressure line, the return and the sump. The sump line is "T" or double manifolded before reaching the sump. This line has no pressure, it just dumps the fluid in the sump. The two valves labeled "loader mounted valve" and "tractor mounted valve", either one can actually be for the loader or for remotes. Both of these valves have Power Beyond. The backhoe has only pressure and return with NO PBY, because it is the last valve in the series.

 

[MadReferee]

Unfortunately, that diagram does not reflect how a Kubota is plumbed.

On a Kubota, oil is sucked from the sump by the pump and sent to the loader valve. The loader valve has a high pressure Power Beyond port which sends the oil to the next valve in the series circuit and a seperate return port line which goes back to the sump.

The loader's high pressure PB line now goes to any tractor mounted valve, which like the loader valve, has a PB out port and its own return to sump port.

The tractor mounted valve's high pressure PB line now goes to the 3pt, which is the last valve in the series circuit. The 3pt has no PB line and its return to sump port is internally plumbed.

If you have no tractor mounted valve then the loader valve's PB port goes directly to the 3pt. The 3pt is not connected directly to the pump but is the last valve in the series circuit.

Since a backhoe typically has no power beyond, it must be the last working valve in the circuit. Some installations have the loader's PB line connected to the backhoe and the backhoe outlet connected back into the main circuit but the 3pt and any tractor mounted valve must be disabled when the backhoe is connected. These type of installations will usually require that the 2 backhoe QD's be looped together whenever the backhoe is not attached.

A proper backhoe installation whould have a QD on the loader's (or even the tractor mounted valve's) PB line. When using the backhoe the backhoe's inlet would be connected to the QD and the backhoe outlet would be connected directly to the sump. This correctly disables any valve after the QD which are usually the 3pt and any tractor mounted valves. When the backhoe is not on the tractor, the line to the 3pt and tractor mounted valves would be connected to the QD. No looping of the 2 backhoe hoses would be necessary.

If you have a Kubota WSM there are nice hydraulic diagrams of the circuit.

 

[JerryG]

This will work for ANY tractor with three lines and open center.

 

[Junkman]

Now that I have put the valve into the line that feeds the backhoe and know that it works, is there any thing that can be damaged by doing this? thanks....

 

[MadReferee]

Jerry,
OK, but where is your 3pt? Is it that little tubular gizzie on the lower left corner? If so where is it getting it's high pressure oil from? You show it getting return oil twice.

And you have the backhoe outlet going to "RETURN". Where is "RETURN"? I believe it would have to go to the sump since it has to be last in line.

In your diagram the 3pt should get its high pressure oil from one of the pairs of QD's on the loader valve's PB line.

 

[MadReferee]

No, as long as your valve has its own return to tank line which it should.

 

[JerryG]

Welll.............I used this drawing because I thought that I read above that his three point was routed internally. I just re-read and Junkman didn't /forums/images/graemlins/crazy.gif say that on this thread. I should have posted a drawing with the three point also external in series. I will try tonight.

 

[MadReferee]

On Kubotas and NH, the 3pt is on the same circuit as the loader and any aux valves. The 3pt plumbing is steel tubing from the loader or aux hydraulic outlet to the inlet and the return to tank is internal to the transmission/rear end depending on the model.

 

[JerryG]

That is the way that I thought that it was on the Kubota's, but I mis-read what Junkman said. /forums/images/graemlins/crazy.gif

 

[Junkman]

I get blamed for everything.... /forums/images/graemlins/mad.gif /forums/images/graemlins/crazy.gif /forums/images/graemlins/mad.gif /forums/images/graemlins/crazy.gif /forums/images/graemlins/mad.gif /forums/images/graemlins/crazy.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

 

[botaman2]

Added Kubota rear hyd. kit to my Kubota L3010 last Jan. In the neutral (mid-pos) the fluid flows thru the valve back to the 3ph mounting. When the valve is operated to either the forward or rear position,the pressure is directed to either the left or right quick-dis at tractor rear.When my valve is operated to the forward position,the right sided Q/D is pres.I then plug in the supply (pres. to backhoe) to this Q/D.I then plug in the (return from backhoe) to the left side Q/D.To make all this work the valve handle is locked in the forward position.The backhoe control valve handles the flow thru,when lines are connected in this way.A word of caution,the tractor mounted valve must never be operated unless a hydraulic cylinder,or flow thru device (backhoe valve) etc. is connected to the rear remotes.

 

[Junkman]

Does your valve have a return line? What would happen if someone "accidental" operated the valve with nothing connected to it? /forums/images/graemlins/confused.gif

 

[MadReferee]

The L series valves are not "external" so to speak. They are attached (stacked) directly to the transmission case and have no hoses for PB, inlet and return to tank. It's all done with internally machined passages. All you have is steel tubing going out to the quick disconnects and linkage for the levers.

Basically nothing will happen if the valve is actuated and nothing is connected. Same as an externally mounted spool valve. No oil will flow since it has nowhere to go. For an external valve, depending on the valve, the relief may activate and dump oil to tank.

 

[Junkman]

Thanks for the explanation. You have confirmed what I already thought to be true. I just figured that after such a stern warning, that it would be advisable to learn what botaman2 was thinging of when he made the statement.... thanks again.. Junk.. /forums/images/graemlins/wink.gif

 

[botaman2]

MadReferee's explanation was correct,the plumbing is as he stated. The warning I gave,was only to discourage valve use when nothing is connected to avoid possible damage to pump.When operated, the engine will slow down dramaticly as the bypass cuts in to relieve this pressure.

 

[lp333]

… The question is now officially resolved… Tonight…I hooked them to the backhoe line. I tried the backhoe outriggers and they lifted the rear of the tractor as usual. I have to assume now that this will work… Junk..

Now that I have put the valve into the line that feeds the backhoe and know that it works, is there any thing that can be damaged by doing this? thanks....

No, as long as your valve has its own return to tank line which it should.

It seems to me that the challenges that BX22 and BX23 owners once faced when trying to add a rear hydraulic remote valve to their tractors have been considerably reduced with the advent of the BX24.

If you take a look at the hydraulic plumbing at the back of the BX24 (going from the tractor to the BT601 backhoe) you will no longer find only two connectors but three. There are as follows:
1) Outlet hose
2) Return pipe, and
3) Power Beyond pipe.

In other words, the owner can now mount a rear remote using only the plumbing connectors found at the rear of the BX24, without the need to run a long return hose towards the front of the tractor as was required on the earlier BX22 and BX23.