Backhoe Hydraulic circuit for power beyond with third function kit on Grand L60

[mljenkins]

Does anyone know how the hydraulic circuit is supposed to be plumbed when using power beyond and third function on a Grand L (L6060HSTC)?

My backhoe keeps leaking at the valve block. When I purchased the tractor, the dealer told me over the phone they were working a problem waiting for the Kubota representative to help them. They mentioned when they hooked up the backhoe, that the loader stopped working, or something regarding the loader, backhoe, and third function not working when they installed all three. My first thought was oh crap, that's not good, because that typically means a fluid stop.

So, speaking with them last week after they worked on the backhoe valve block again to try to stop the leaks, I asked why it kept leaking and then told me it likely had to do with that event when they were installing everything. Given the block is still leaking when using the backhoe, I don't trust the plumbing on this thing anymore.

When I trace the lines, there are two ports on the top of the back hydraulic block, one on the left, one on the right. The one on the right seems to be the output that goes to the power beyond hose, which then goes through the backhoe to complete the circuit. After coming back from the backhoe (or if the backhoe is not there), the flow goes to another hose that is connected to the third function block on the middle right of the tractor. Out of the third function block it comes back to the back of the tractor and back to that left side port on the rear hydraulic block.

Now, those left and right ports seem to have a tee, and there are hard lines from them going up to the front hydraulic block. I'm not sure if this is the feed for the front hydraulic block, or if this is feed for it. Nonetheless, those two hard hoses go up to the front and appear to be in parallel with the power beyond.

So, I guess my questions really are:
1. Is the third function valve block supposed to be in series with the power beyond (for backhoe)?
2. Is the power beyond supposed to be in parallel with those hard lines going to the loader?

Also, I found a service manual for an L3540 online but it hasn't helped any. It doesn't mention the power beyond nor the third function kit. I thought about purchasing a service manual, but I don't want to sink the money in one if it won't show the circuit diagrams for the third function and backhoe (BH92). If anyone can recommend which manual I would need for this and where to source one (even if I need to pay for it), I would appreciate it.

I'm not saying things are wrong here, but what I am saying is I don't trust what has been done. I've had the tractor in the shop now three times, the last time for over a month, trying to fix the leaks on the backhoe, and it comes back the same every time. The problem is if I take it somewhere else to have it looked at, the backhoe is out of the year warranty and I am going to get charged for any work on it, despite the problem originating from my dealer's mistake. So I'd like to make sure the main circuit is plumbed correctly before taking it back in there and having it come back the same again.

Also, here is a picture of the ports on the rear hydraulic block where the lines come off of:

 

[mljenkins]

I was looking at some parts diagrams over lunch.

My third-function kit is L2265 and the backhoe mount kit was BH4982. I can't find the BH4982 on Messick's parts diagrams, but they do have BH4983 which I assume is pretty similar.

The joint in my picture I thought was a tee, but it looks to be an elbow from what I can tell. That part # is 7K505-16910 and used for both the backhoe install kit and the third-function. So considering that is an ell and not a tee going into the block, then the backhoe and loader must be in series, and without a backhoe the loader and third function would be in series, so hence with all three they would all three be in a series like they are now. I'm still confused as to how they managed to have whatever issue they did during the initial install, but I can see how it happened when I can't find any diagrams of all three together.

I really wish I could see a hydraulic circuit diagram for all three components, loader, backhoe, third-function. It would be nice if the diagram mentioned the 3 rear remotes as well.

Maybe this is another stupid question, but how does the third function relieve without a relief? Would that then occur at the front or rear block? The dealer told me it was safe to use the third function with the backhoe attached when I asked them about it a couple weeks ago.

Anyone have any idea where I would find a circuit diagram for all the components together? Just trying to wrap my head around this to have a better comfort level that things are as they should be.

 

[100 td]

How they have plumbed in the valves and backhoe circuit. Generally the backhoe would simply go in series with the 3pt but if they have plumbed it incorrectly they probably have the PB and T ports swapped on the backhoe valve, which would probably stop the FEL/3PT.
Edit: Wrong manual listed!

 

[mljenkins]

Download the service manual link below and spend some time marking up the hydraulic circuit diagram to exactly what you have on your tractor and establish where/how they have plumbed in the valves and backhoe circuit. Generally the backhoe would simply go in series instead of the loop at the top of the diagram. I've only glanced the circuit, will wait till you check out your routing, but if they have plumbed it incorrectly they probably have the PB and T ports swapped on the backhoe valve, which would probably stop the FEL/3PT.
M6060

Thanks, I looked through it and it looks similar to the circuit in the Kubota L3540 Workshop Manual I have been studying this evening. From what I can tell, the flow comes from the pump, to the front hydraulic block, to the loader valve block, back to the front hydraulic block, then to the rear hydraulic block. At the rear block it goes to the auxiliary remotes, then to the 3-point lift control, and then back to the tank.

The issue is the loader, backhoe, and third function are not shown in the circuits. Somehow they either come off that front or rear block. The reason I can't see this is because of the cab. It looks like the seat somehow comes off and there is a service door that allows access down there, but it looks sealed up pretty good so I hate to tear into all that.

To figure out this puzzle I think I'll need the LA1055 and BH92 circuit diagrams. I found a WSM for a LA344 but it appears to be a vary different circuit for the third function than the larger tractors.

 

[100 td]

FEL's are generally similar, sometimes taken from pump (eg. front hydraulic block) and must include a relief valve, P, PB & T; PB heading on to 3pt and/or remotes. Looking at your pictures, it appears 90 degree hoses were removed and now joined to other hoses, probably backhoe. Check where they run, as earlier stated possibly hooked up incorrectly, check what goes to and from your backhoe valve body.

 

[100 td]

My bad, read incorrect model numbers previously, gave you an "M" manual instead of an L. Follow the hoses from the hoe block back.

 

[100 td]

The issue is the loader, backhoe, and third function are not shown in the circuits. Somehow they either come off that front or rear block.

Looking at the L3540/5740 circuit you probably have (hope it's similar to 6060), it does show the auxiliaries, and the hoe will likely be plumbed in before or after them, and the FEL, probably to the front block where the takeoff loop is shown. Where do your FEL hoses connect?
Get you phone and set it on video and shove it down behind the cab and twist it all around then review footage to help see where hoses go etc.

 

[100 td]

I had a look at the parts diagram, flow goes as follows, pump>loader valve> SPACER(removed, now backhoe)>3pt
Your remotes bolt directly to the 3pt(rear block) so are after the backhoe.
In your picture you can see pipe fittings left and right of the 3pt where hoses have been attached, the spacer(070) has been removed, this is where they have broken in to run hoses to the backhoe I expect. Is the backhoe using QC valves?

 

[mljenkins]

I had a look at the parts diagram, flow goes as follows, pump>loader valve> SPACER(removed, now backhoe)>3pt
Your remotes bolt directly to the 3pt(rear block) so are after the backhoe.
In your picture you can see pipe fittings left and right of the 3pt where hoses have been attached, the spacer(070) has been removed, this is where they have broken in to run hoses to the backhoe I expect. Is the backhoe using QC valves?

Hey thanks for the diagram, I never looked at the oil line diagram to find those pipes. Also, sorry I missed your PM last night I had just went to sleep.

So this makes sense because they tell you not to use the rear remotes with the backhoe.

So basically I think I have:

1. Pump
2. Relief
3. Loader boom valve
4. Loader bucket valve
Out PB Port on front hydraulic block to right side of rear block into backhoe power beyond QC
5. Backhoe valve block
Return through backhoe power beyond QC but into third function hose tie in
6. Third function valve
Into left side of rear hydraulic block lines (where spacer is removed for PB addition) and into rear hydraulic block
7. Auxiliary remote valves
8. 3-point lift
9. Return to tank

It looks like in the diagrams there is another relief (not the cylinder safety valve) in between the auxiliary remotes and the 3-point lift position. The symbol is on the diagram, but it's not mentioned on the key. Maybe that is the same relief that is on the front block, because that would probably make more sense considering I don't see it in a parts diagram and never heard of one back here.

Still trying to wrap my head around it... Have to think on it a bit more tonight.

 

[mljenkins]

I did some more quick reading over my lunch and reviewed my videos I had taken of the hoses last night.

Bottom line is, the circuit is currently setup loader, backhoe, third function, aux/3pt. So the third function valve is after the backhoe.

Everything I have seen on these forums seems to indicate the third function should be before the backhoe. This seems to make sense otherwise when the valve is actuated the pressure is going to go back on the backhoe block and not directly to the relief at the loader block.

I don't know if this is what is causing the leaks on the backhoe block, because it was leaking when it came back from the dealer even before I used the third function. However, it probably isn't helping anything.

I guess it would probably be helpful to get the L2265 third function install manual, but I haven't found one online yet.