Can't find tank return line

[ericm979]

In a power beyond system using valves that have tank ports you are correct.

Even with a valve with a PB port, say a system with just a loader and 3pt valves, the loader valve can see up to full system pressure, if you're lifting the max capacity with the 3pt. I guess technically only part of the valve will see that pressure- the tank port won't. And it's work ports won't at that time though they could when using the loader.

With open center systems the valves ahead of the valve doing work are essentially just pipes between the pump the the valve doing work.

 

[ericm979]

I may get to the point of thinking outside the box. Like the fill tube or drain a drain plug.

That'd be appropriate for the tank port if you're using a valve with a PB port.

You need to direct the work flow to the 3pt valve inside the cases if you want to be able to use it with your new valve plumbed in.

If you use a valve with a PB port you can plumb the tank port into a tee in the tank line from the loader valve. Assuming it has one, some don't.

 

[brianrohr13]

Re: Can't find tank return line L4240

Where is that diagram from? I'm not finding that view on mine. I went through kubotausa com

I then went to parts, then illustrated parts list. Mine is L4240HST-3.

 

[brianrohr13]

Re: Can't find tank return line L4240

Good point, I was looking at the valve backwards.
About the only option I see would be to cut line 110 in this diagram and put in a compression tee:
View attachment 650724

Aaron Z

While I don't have exactly what's in your picture (it's an option), I do have the same base. We may be onto something. I don't have line #110 but I have a plug #230 right there. So if that indeed dumps to tank, that would work. I could maybe even purchase that line #110 and then tie into it. The hole is smooth bore and the plug just pushes in. Here are my pictures. Also, not the biggest hole so I'm wondering what it needs to support as far as flow.

 

[Michael In Tennessee]

Re: Can't find tank return line L4240

If you use a valve with a PB port you can plumb the tank port into a tee in the tank line from the loader valve. Assuming it has one, some don't.

It doesn't, which is the problem.

Good point, I was looking at the valve backwards.
About the only option I see would be to cut line 110 in this diagram and put in a compression tee:

Aaron Z

Excellent catch. This might work. As the OP said, he doesn't have rear remotes now, so that port is plugged and available.

While I don't have exactly what's in your picture (it's an option), I do have the same base. We may be onto something. I don't have line #110 but I have a plug #230 right there. So if that indeed dumps to tank, that would work. I could maybe even purchase that line #110 and then tie into it. The hole is smooth bore and the plug just pushes in. Here are my pictures. Also, not the biggest hole so I'm wondering what it needs to support as far as flow.

Doesn't need to be big. Buying that hard line and having a JIC flare brazed/welded to the end would work.

 

[Leejohn]

Re: Can't find tank return line L4240

While I don't have exactly what's in your picture (it's an option), I do have the same base. We may be onto something. I don't have line #110 but I have a plug #230 right there. So if that indeed dumps to tank, that would work. I could maybe even purchase that line #110 and then tie into it. The hole is smooth bore and the plug just pushes in. Here are my pictures. Also, not the biggest hole so I'm wondering what it needs to support as far as flow.

Take plate #200 off that might be where it is to hook into.

 

[Michael In Tennessee]

Re: Can't find tank return line L4240

Take plate #200 off that might be where it is to hook into.

If you look at Aaron's picture, you will see only two of the three necessary lines go through where plate 200 is. The third line (tank) goes where we are discussing. We know its tank and not P of BY, because when the rear remotes are not installed, a simple o-ringed plug caps it off.

 

[ericm979]

If you can't find the tank line, add new valve(s) that don't have PB, only tank, and run that into the port that provides pressure to the 3pt. That's how your BH valve stack works and how the dealer added rear remote on my Branson works (and how my BH's valve stack works). As long as the valve is rated for it, it works fine.

(it's confusing to use "tank" both for the low pressure port that really runs to tank when there's a PB port passing on the high pressure, and for the port that combines both flows when there isn't a PB port. But that seems to be the usage. Hopefully it's clear in my posts which I'm talking about)

 

[Bill_M]

I am not sure which transmission you have so adjust accordingly.
There is a steel line on the valve that is the return to tank s/n dependant - Look @ H23300 Hydraulic return line illustration, H280xx is your loader valve. should be a link below:
Kubota L424HSTC (Hydrostatic Transmission / Cabin / 27 - 29) Parts Diagrams
Then look at the loader section & 3rd function kits link below:
Kubota LA854 (FRONT LDR / L424 / 474 / 5 / 524 / 574) Parts Diagrams
item# 04 shows a loader return line that will have an addition fitting on it that you can attach a return hose to.

 

[Michael In Tennessee]

The is about all I can find for pics. A couple drawings from Kubota website of what I believe is the right valve. The spot that was curious to me in the drawing was the O ring. Wouldn't need O ring just to bolt on a valve to the side of the case. In thinking maybe that's the passage for the fluid to tank? One of the drawing shows where the pressure relief is. As for my pictures. I got a view of under the seat, a side view, and a shot from up underneath.

I am not sure which transmission you have so adjust accordingly.
There is a steel line on the valve that is the return to tank s/n dependant - Look @ H23300 Hydraulic return line illustration, H280xx is your loader valve. should be a link below:
Kubota L424HSTC (Hydrostatic Transmission / Cabin / 27 - 29) Parts Diagrams
Then look at the loader section & 3rd function kits link below:
Kubota LA854 (FRONT LDR / L424 / 474 / 54 / 524 / 574) Parts Diagrams
item# 04 shows a loader return line that will have an addition fitting on it that you can attach a return hose to.

If you look at Brian's post 15, last picture, you see a view of the valve from below. There is no return line like your reference shows. The bolt you see is the pressure relief valve, not an unused port either. However, it would be worthwhile for Brian to see whether there is an unused port on the transmission where located on your referenced part list (option 5 drawing).