Install L3901 HST rear remotes with Factory 3rd function and BH77 Backhoe?

[NewtFarms]

I am pretty savvy about all things electrical, but but I do not quite understand tractor hydraulics.

I have a 2022 L3901 HST with a dealer installed front 3rd function to run grapple, and a power beyond rear port to run a BH77 backhoe. I want to run a ditch bank offset flail mower that tilts and can extend and retract from the Tractor. It has 4 hydraulic lines, so I need a 2 spool rear remote. I do not want to lose the ability to use the grapple when using the mower, so I can pick up rock or other impediments. I contacted summit hydraulics, told them what I wanted to do and was told their Kubota rear remote kit was what I needed, so I purchased it.



When I got the Summit kit, the instructions tell you to remove the power beyond hose from the mid tractor manifold, and discard the hose and connect the hose that powers the rear remote. In their instructions, the power beyond hose appears to go up to the joystick that runs the bucket and 3rd function. It appears to me that the way their set up is, I would not have a rear power beyond port to run the BH77, if i install their rear remotes. My understanding is when the BH77 is removed, the power beyond hoses need to be hooked together to provide a hydraulic flow loop. Obviously, I would not be using the backhoe and the mower at the same time, but is there a way to install the rear remotes, retain my front 3rd function, and have the power beyond port available to run the back hoe when needed?

Would it work to connect the power beyond ports to the summit hydraulics valve block via a short hose and and a pioneer connector that matches the power beyond hose and then just disconnect the hose and hook it up to the backhoe when needed? I dont know if the summit hydraulics valve block has flow through it at all times or just when the valves are being actuated.


I feel like someone out there has figured out how to do this already.

I have contacted Summit, but it has been a few days and they have not responded.

 

[Russell King]

You need to apply your electrical knowledge to the hydraulics system since they are very similar systems.

The hydraulic pump on the engine supplies flow to all of the hydraulics on the tractor. The pump flow goes through the valve and exists the valve through an adapter sleeve (power beyond) and on to the next valve or back into the tractor to be distributed to other valves internally. Eventually the fluid ends up at the three point control valve and dumps back into the sump where it started.

The valves just divert the flow to a cylinder when you activate the valve. Then pressure will build up in the pump and cylinder until it moves the cylinder. So if you are actuating the first valve in the system the remaining valves will not really have flow to them, since it is diverted. As a cylinder extends (or retracts) the fluid on the opposite side of the cylinder has to be moved out of the cylinder. That flow is low pressure and is called tank return.

So the system above is called open center and the flow is really from pump through valve to valve to backhoe to three point control valve to sump. Then that flow can be diverted by any of the valves.

So if you didn’t have a FEL or backhoe installed the only hydraulic valve would be the three point control valve.

Most newer Kubota tractors have a hydraulic tap block installed to allow the additional hydraulics to be easily installed. That block may have a valve on it that diverts the flow out of the block when additional hydraulics are added or turned the other way to keep the hydraulic flow as original. Older tractors just had a cover on the block that was replaced with a different cover to tap into the hydraulics. I believe that you have the type where the cover is just replaced.

So in your case you can locate that block and see that the block should have three hoses connected to it. One hose should go to the FEL valve and connect to the P port on the valve. That line is the power out of the tractor pump. One of the lines should go to the FEL valve and connect directly to a T port. That line is tank return (which is basically a drain line). Then the remaining line should also go to the FEL valve to a port also labeled T on the valve BUT there should be a fairly large sleeve adapter between the hose and the valve. This is the power beyond sleeve and that line is the power beyond line going back to the tractor to provide power onto the next valve. So you should identify each of those lines to help you understand how the power is flowing.

Now from the FEL valve there are an additional four lines that go to the FEL lines and connect to cylinder ports. You don’t need to worry with them for your situation. Just know they are the power out of the FEL valve when you actuate the joystick.

Now since you have a third function involved that is a bit more complicated but only because it can be placed before the FEL valve or after the FEL valve. You will have to figure that out but I will assume it is after the FEL valve. In that case the power out of the FEL valve should go to the third function valve P port, then out of the third function valve and down to the hydraulic block on the tractor.

Since you have a backhoe there is already a circuit out of the rear of the tractor that you attach the backhoe valve to. That port provides power to the backhoe valve which then return the flow to the other port back to the three point valve and dumps into the sump. The backhoe valve will probably not have a power beyond sleeve in it since it is essentially the last valve in the chain. There really is the three point valve left in line BUT it can’t be used if the backhoe is installed so can’t back pressure the FEL valve. That is why there is no PB sleeve in the FEL valve.

You can add the rear remote valve and retain all other functions you currently have, so don’t worry about that.

I think what they are telling you to do is to run from your third function valve out port to the input power port on the rear remote valve then through the rear remote out the PB sleeve on the rear remote back to the tractor block where the previous PB line had been installed.

To me I would say it as:
Remove the line from the third function valve that returns to the tractor block (PB return). From that port on the third function valve then route a line to the rear remote valve power in (P) port. From the rear remote valve PB sleeve route a hose to the tractor block where the return line from the third funtion valve was attached. Then run a tank return line from the T port on the rear remote valve to connect with the other tank return lines at the block on the tractor.

The tank return lines are the ONLY lines that can be connected together in a tee type configuration since they flow directly to the sump as a low pressure return.

Sorry for being so long winded and hope it all makes sense. If not just ask more questions.

 

[TheOldHokie]

I am pretty savvy about all things electrical, but but I do not quite understand tractor hydraulics.

I have a 2022 L3901 HST with a dealer installed front 3rd function to run grapple, and a power beyond rear port to run a BH77 backhoe. I want to run a ditch bank offset flail mower that tilts and can extend and retract from the Tractor. It has 4 hydraulic lines, so I need a 2 spool rear remote. I do not want to lose the ability to use the grapple when using the mower, so I can pick up rock or other impediments. I contacted summit hydraulics, told them what I wanted to do and was told their Kubota rear remote kit was what I needed, so I purchased it.



When I got the Summit kit, the instructions tell you to remove the power beyond hose from the mid tractor manifold, and discard the hose and connect the hose that powers the rear remote. In their instructions, the power beyond hose appears to go up to the joystick that runs the bucket and 3rd function. It appears to me that the way their set up is, I would not have a rear power beyond port to run the BH77, if i install their rear remotes. My understanding is when the BH77 is removed, the power beyond hoses need to be hooked together to provide a hydraulic flow loop. Obviously, I would not be using the backhoe and the mower at the same time, but is there a way to install the rear remotes, retain my front 3rd function, and have the power beyond port available to run the back hoe when needed?

Would it work to connect the power beyond ports to the summit hydraulics valve block via a short hose and and a pioneer connector that matches the power beyond hose and then just disconnect the hose and hook it up to the backhoe when needed? I dont know if the summit hydraulics valve block has flow through it at all times or just when the valves are being actuated.


I feel like someone out there has figured out how to do this already.

I have contacted Summit, but it has been a few days and they have not responded.

Many peiple including Kubota have figured this out.

You simply insert thdenew valve between BH and the third rfunction

1. Disconnect hose going to BH from T port on third function
2. Connect T port on third function to P port on new remote valve
3. Connect BH supply to PB port on new valve.
4. Connect T port on new valve to T port on mid outlet using a tee fitting

Done.

Dan

 

[NewtFarms]

 

[NewtFarms]

This is a picture of the valve coming out of the pump. The top left hose (the dirty one) goes straight back to the rear of the tractor to a female pioneer coupler that attaches to the backhoe. The other line that goes to the backhoe has a male pioneer coupler at also attaches to the backhoe, it has a short hose attached to it and then connects to a hard line. I was assuming this was the return line. When the backhoe is not attached you connect the male and female end together and the hydraulic oil is supposed to circulate in the loop. Since those hoses are already at the rear of the tractor, can I hook them to the 2 spool valve body to the T & P ports and have it work?

 

[TheOldHokie]

This is a picture of the valve coming out of the pump

Since this hoses gostraight bacj to the rear of the tractor, can I hook them to the 2 spool valve body to the T & P ports and have it work?

That is a picture of the hydraukic outlet block. It is not a valve.

The answer to hooking your new vakve to the the BH outlets is NO. You need a remote valve with P, T, and PB ports. You could use the backhoe connections for P and PB but you still need a third tank return

The hose going to the female backhoe outlet is pump pressure. It should currently be connected to the T port on your third function valve. That is were you insert the new valve as follows:

1. Disconnect the hose from the third function valve.
2. Run a new hose from the third function valve to the P port on your new valve.
3. Connect the hose you disconnected in (1) to the PB port on your new vakve. Its pribably too long so replace it with sonething shorter if needed.
4. Install a tee on the bottom right hose connection on the outlet block. That is tank return
5. Run a hose from the T port on your new valve to that tee.

DONE

The new valve is now a permanent full time addition to the hydraulic system and the backhoe connections work exactly as they did before the addition.

Thats the plumbing - simpLE and easy to connect.. The bigger question is do you understand what a renote valve with "power beyond" is and do you know what/where to buy? If not ask before jumping in.

Dan

 

[NewtFarms]

That is a picture of the hydraukic outlet block. It is not a valve.

The answer to hooking your new vakve to the the BH outlets is NO. You need a remote valve with P, T, and PB ports. You could use the backhoe connections for P and PB but you still need a third tank return

The hose going to the female backhoe outlet is pump pressure. It should currently be connected to the T port on your third function valve. That is were you insert the new valve as follows:

1. Disconnect the hose from the third function valve.
2. Run a new hose from the third function valve to the P port on your new valve.
3. Connect the hose you disconnected in (1) to the PB port on your new vakve. Its pribably too long so replace it with sonething shorter if needed.
4. Install a tee on the bottom right hose connection on the outlet block. That is tank return
5. Run a hose from the T port on your new valve to that tee.

DONE

The new valve is now a permanent full time addition to the hydraulic system and the backhoe connections work exactly as they did before the addition.

Thats the plumbing - simpLE and easy to connect.. The bigger question is do you understand what a renote valve with "power beyond" is and do you know what/where to buy? If not ask before jumping in.

Dan

You are right, the photo is of the hydraulic outlet block. I called it the wrong thing as I was trying to think of how to describe it. I bought the Summit Hydraulics Kubota Rear Hydraulics remote kit after reading suggestions on this forum and talking to them. When I got it reading through their instructions, i don't think their kit is set up to hook up the hydraulics if you already have a 3rd function and use a backhoe. The electrical part of the installation is easy for me, my grandfather was an electrician so I have been around that all my life. I have only had the tractor a little while, after purchasing a home with some acreage, but Ive use the backhoe, mowers etc quite a it. I decided an offset mower flail mower would best suit my property and now I am trying to figure out how to be able to use it. Tractor hydraulics are totally greek to me.

 

[TheOldHokie]

You are right, the photo is of the hydraulic outlet block. I called it the wrong thing as I was trying to think of how to describe it. I bought the Summit Hydraulics Kubota Rear Hydraulics remote kit after reading suggestions on this forum and talking to them. When I got it reading through their instructions, i don't think their kit is set up to hook up the hydraulics if you already have a 3rd function and use a backhoe. The electrical part of the installation is easy for me, my grandfather was an electrician so I have been around that all my life. I have only had the tractor a little while, after purchasing a home with some acreage, but Ive use the backhoe, mowers etc quite a it. I decided an offset mower flail mower would best suit my property and now I am trying to figure out how to be able to use it. Tractor hydraulics are totally greek to me.

There is nothing new or special in your situation. Backhoe and third function simply change the hose connections on the Summit kit. If Summit includes hoses you may need to replace them with different lengths.

The Summit kit gets hooked up the same way I described in my previous response except it does not need the third tank return hose.

1. Disconnect the BH supply hose from the third function valve.
2. Using a new hose of the appropriate length connect the third function valve to P on the Summit manifold
3. Connect the backhoe supply hose to T on the Summit msnifold. You may have to replace it with a different length.

Thats it for the hydraulics.

Dan

 

[NewtFarms]

There is nothing new or special in your situation. Backhoe and third function simply change the hose connections on the Summit kit. If Summit includes hoses you may need to replace them with different lengths.

The Summit kit gets hooked up the same way I described in my previous response except it does not need the third tank return hose.

1. Disconnect the BH supply hose from the third function valve.
2. Using a new hose of the appropriate length connect the third function valve to P on the Summit manifold
3. Connect the backhoe supply hose to T on the Summit msnifold. You may have to replace it with a different length.

Thats it for the hydraulics.

Dan

That's what I thought but I wanted to make sure.

Thank you.

Mike