3pt hitch Hydraulic top link and control

[joea99]

I think I know now though. Consider above I described an open center valve where PB and tank were combined. It works because, being the last valve in a system, PB has nothing to do so PB and tank just flow together. Now, after the BH, there is the 3PH. The 3PH is also open center and fluid just flows through the middle if it is doing no work. Since it never does work with the backhoe attached, it is effectively just a pipe with blended tank and PB flow. Your new rear remotes will not have that scenario, so we need a tank line.

I get that. So, "living dangerously" I could send the valve T and PB to the same place (P) for the 3pt hitch AS LONG as I remember to never use the raise/lower on the 3pt at the same time as the tilt and/or top on the box blade, or whatever. But I guess that is not optimal if I got a 3 or more spool for some future toy. The way my memory has been getting lately, it might be better for forget that entirely

I'd not do that unless you want to invest in tubing bending and flaring tools. Not fun without the right tools. I really want JIC flaring tools, but its just too much money.

Post again your tank port picture on the tractor. We need to figure out how to get two lines teed in there. If I recall, it was a hard line with a banjo fitting. You can get banjo fittings on rubber hoses too. I'm thinking a short hose with a banjo on one end and a JIC on the other. A JIC tee. and then one rubber line aft and one back to the loader valve with whatever fitting is needed. I usually use a JIC on the hose and an adapter on the valve body if needed.

This is all I can come up with at this hour. It is night, cool, raining, so, no shots tonight.

 

[Leejohn]

I don't know if this is going post, but it does maybe it well help.

http://www.princehyd.com/Portals/0/valves/RD5000InstS.pdf

Well it looks like it did. Read everything on the drawing.

 

[Michael In Tennessee]

I'm having second thoughts on the selector valve and the BH circuit working with the 3ph selected. I read somewhere on another forum that it may be problematic. Is it possible to test? Can the backhoe and 3ph operate at the same time? Your second pic above says "return from BH or loader ", which gives me hope.

 

[joea99]

I don't know if this is going post, but it does maybe it well help.

http://www.princehyd.com/Portals/0/valves/RD5000InstS.pdf

Well it looks like it did. Read everything on the drawing.

Thanks that is the clearest manufacturers explanation I've seen so far. Seems to be no doubt their design "wants" to have a direct return to tank, no matter
what the configuration. However, their PB note provokes the same thought about actually needing the T (outlet) connection when using a downstream valve that
has a dedicated T connection, in the case the 3pt hitch. After all, the BH does that already. But, I guess, there is zero chance the 3pt will be in use with the BH still
hooked in.

Could probably save myself a lot of aggravation (if not $) by just doing it their way.

 

[joea99]

I'm having second thoughts on the selector valve and the BH circuit working with the 3ph selected. I read somewhere on another forum that it may be problematic. Is it possible to test? Can the backhoe and 3ph operate at the same time? Your second pic above says "return from BH or loader ", which gives me hope.

I am not sure what that means. The Kubota WSM and other docs are not always clear or consistent in how they refer to "things". I'll just have to break down and crawl under there, after the ground drys a bit, and hand over hand it. With some cleanish rags and a light. LED, of course.

Seems like the idea of plugging into the existing BH connections will not fly. Or float, if you are a sailor.

There is a 2 position "selector valve" that selects BH or 3pt hitch. Looking at the diagram again, it suggests the 3pt hitch "selector valve" functions to connect flow to T (in BH position)(?) or to "flow through" to the 3pt lift control with its tank connector.

Perhaps all these kits that hook into the front circuits had this all figured out to begin with? Ya think?

 

[Michael In Tennessee]

Well, I'm not sure. If you go back to your posted diagram Hyd1.pdf and look at the hydraulic block (item 1) you have valves 5 and 6. I have no idea if they are separate and move independently or not. But, with valve 6 in the closed position, flow goes to loader and BH and in the open position, flow can either go to the Loader and BH or bypass, which is weird. Also, it is listed as a "control screw". I wonder if it just turns on/off this flow if the loader is not installed.

Now, valve 5 seems to be a 3ph bypass. Closed, the 3ph works, open it doesn't as the low resistance path is to tank. However, you will note that the loader and BH are on the same loop, so if something turns off the BH, it also turns off the loader. If the loader works, then something you replace the BH with (rear remotes) should also work.

When you use the 3ph, does the loader work too? If so, this should work.

 

[joea99]

Well, I'm not sure. If you go back to your posted diagram Hyd1.pdf and look at the hydraulic block (item 1) you have valves 5 and 6. I have no idea if they are separate and move independently or not. But, with valve 6 in the closed position, flow goes to loader and BH and in the open position, flow can either go to the Loader and BH or bypass, which is weird. Also, it is listed as a "control screw". I wonder if it just turns on/off this flow if the loader is not installed.

The "control screw" (6) in that diagram, controls flow to either the FEL or the 3pt hitch, according to the WSM. My guess is it is there for units that will normally not have, or never will have, a BH attached. Does not look easily accessible

Now, valve 5 seems to be a 3ph bypass. Closed, the 3ph works, open it doesn't as the low resistance path is to tank. However, you will note that the loader and BH are on the same loop, so if something turns off the BH, it also turns off the loader. If the loader works, then something you replace the BH with (rear remotes) should also work.

When you use the 3ph, does the loader work too? If so, this should work.

It does seem like 5 either passes to 3pt hitch, or dumps to tank, thereby providing the BH tank connection. You may have a point as it seems pressure will still be supplied and it should work. Perhaps I was under caffeinated this morning.

I've never actually used the 3pt hitch and the previous owner claims he did not either. It did not have the 3pt hitch hardware, so I purchased a B26 kit a local dealer had collecting dust. Been thinking I should at least see if it operates before I go any further.

/Edit: I "should have" tested the 3pt hitch BEFORE I bought that Wood Box Blade/scraper. Shows how clear my thinking is getting. . . /End Edit.

I'm not gonna test it (just for grins) until I change the leaking hose and its mate and the two on the right cylinder. They all look badly weathered. Fed Ex will be here today.

 

[Michael In Tennessee]

Well, post back when you have more info.

 

[joea99]

With the hoses. reluctant BH release levers and other time consumers behind me now, the 3pt and the loader do function at the same time, but do not seem to be
particularly happy about it, the 3pt seeming to act a bit "jerky" on lift. Guessing that is due to the loader valve getting first taste.

now I just have to decide on a spool valve and how to plumb things in. The single biggest question is, I guess, the spool valves. Most of the cheaper ones I have seen seem to be huge cast iron deals, which I understand take up a lot of space.

May have plenty of time as no idea when the Kubota kit will come in and probably need to wait for that to figure out fittings and such.

After testing the box blade to be sure the B21 could pull it, a bigger machine would be better suited. I will have to learn to pace myself AND the machine to avoid overheating either one.

I am absolutely sure I do not want to be getting on and off to adjust the top and tilt. While it is "do-able", it take a lot of time and in this hot spell, is no fun at all.

 

[Michael In Tennessee]

Most folks manually adjust. Its not that bad. But a top cylinder is awful nice. I still don't have a tilt cylinder.