Help tapping into HYDRO Kubota b5100

[LazyGator]

I am making a FEL for my Kubota B5100e, in an effort to save costs I would like to use the existing hydraulic pump, in theory I should be able to tap it somewhere for the feed and find a return line to add. I don't know Hydraulics very well at all this is my first time dealing with them, any help would be great.

 

[BeezFun]

Most tractors provide a place to connect to supply and return. There is typically a small block held on with bolts to cover the open ports. You buy a block to replace that cover that has threaded fittings on it that allow you to thread in a hose that goes to the supply/return on the loader valve. That is not a large tractor, it's possible it didn't offer a loader as an option. But it may have provided a way to add rear hydraulics, so look around on the transmission for something that looks like a cover or plug for access to the hydraulic system.

 

[rScotty]

These older compact tractors typically had the hydraulic pump up on the engine, and most of them were plumbed so that the only use for the hydraulics was to feed fluid under pressure to the 3pt lift hydraulics at the rear. Usually via a steel pressure line about 3/8" in diameter.

It was possible to interrupt that line with a "Y"" flow divider block and tap off some of the pressure to run a loader. The block was nothing more than a block of aluminum about 1"x4" threaded and drilled internally to serve as a "Y" type connector. As Beezbun wrote, the factory blocks sometimes also had some holes drilled to mount the divider block to the top of the transmission case.

But all too often this system meant that the ran slow, and worse yet....the 3pt worked erratically. Adding a either/or type selector valve to the divider block allowed just one system to work at a time and that was an improvement....but then you couldn't use both at once. So if one had leaky cylinders, then both suffered.

The best solution on those under 20 hp tractors was for the loader to use an accessory hydraulic pump, often one that was driven off the front of the crankshaft and had its own oil reservoir in one of the loader uprights. Look around at some older compacts and you'll see what I mean.

 

[ptsg]

I second 100% what said.

On the B7000 I had, I used a 0.366 ci pump, if I recall correctly.

The stock pump is like 0.122 ci or something close to that. I once had one of this pumps apart to figure out the displacement. It would work on a loader but as said, just way too slow.

If you still end up going that route, make sure you get a valve for the loader with power beyond capability and the proper power beyond sleeve for that valve.

With the valve figure out, you can then take the hardline from the pump to the 3 pump. Either cut in half or just replace everything with hoses, but you run a hose from the pump to the In port of the loader valve, then a hose from the Power Beyond port to the 3 pt hitch. Then figure a way to run the Tank line of the loader valve back to the transmission sump.

 

[Leejohn]

I posted your parts manuals for the 4 wheel drive and the 2 wheel drive. Don't know what you have so just done both.
It looks like you well have to cut the pressure line and jump up to the loader valve in port.
The loader valve well need a PB fitting, then that line well go the line you just cut. The return line from the loader valve well have to dump into the rear end. You well have to see if you can find a way to do that.

 

[LazyGator]

Thank you for all the help, If I were to mount a external pump lets say to the front crankshaft, the engine spinning is counter clockwise if I remember correct, does the rotation the pump is spinning matter? or is it directional?

 

[LazyGator]

In addition I'm not 100% confident in my abilities to splice and dice the lines, knowing me I'd probably manage to do it backwards

 

[LazyGator]

I second 100% what said.

On the B7000 I had, I used a 0.366 ci pump, if I recall correctly.

The stock pump is like 0.122 ci or something close to that. I once had one of this pumps apart to figure out the displacement. It would work on a loader but as said, just way too slow.

If you still end up going that route, make sure you get a valve for the loader with power beyond capability and the proper power beyond sleeve for that valve.

With the valve figure out, you can then take the hardline from the pump to the 3 pump. Either cut in half or just replace everything with hoses, but you run a hose from the pump to the In port of the loader valve, then a hose from the Power Beyond port to the 3 pt hitch. Then figure a way to run the Tank line of the loader valve back to the transmission sump.

Okay so I just had a thought, If I did this with the lines and got rid of the hard line that is there, ran the new line from the pump where it already connects run it with some kind of diverter valve so if I want the loader I can just turn the valve to allow flow up to the loader controls, then if I need 3ph I turn it the opposite way to allow flow the normal route, for the return I could find the proper thread size, and take out the oil fill into the transmission have it flow straight back into there?

 

[LazyGator]

This is the idea I sketched up with my understanding it should work, any suggestions? I feel like I am on the right route

 

[LazyGator]

I know I am asking a lot of questions but I thought of another... if I have pressure into a spool control valve that has a power beyond setup can I run the beyond part into my 3 point, and not run a return line since the 3 point has one?