3pt hitch Hydraulic top link and control

[joea99]

Got a Kubota B21 with WR Long 4 in 1 bucket, with the control valve up front. I don't think this is a Kubota specific question.

I just bought a 54 inch Woods Box Blade (scraper they call it) and was thinking I should spring for a hydraulic top link. I guess I am feeling my age.

Looks like all I really need to do is get the correct length range Cat 1 top link and add hoses and a control valve. There are a couple shops around (NAPA and Parker) that can make up hoses for me.

I have a handle on hydraulics basics, changed hoses, filters, etc, and have some recollection of terms from my navy days (from required cross training, not my specialty) but do not know much of the current terminology to quickly figure out what I need.

Question regards the control valve. I'm hoping to find something that I can slip into the hydraulic line, either to the front bucket or the hitch raiser/putter downer, and when idle, with just allow flow though it as if it were not there. I figure, maybe wrongly, that since I am not going to be using all of those at the same time, that could work fine.

Got any good words.

 

[joea99]

Umm, well. I just woke up and realized I will have the backhoe removed, so, the hoses will be right there, I guess I can use them rather than do a Rube Goldberg setup.

 

[Michael In Tennessee]

Yes, just insert your valve where your backhoe would go. If two hoses for the backhoe, you need to find a place for the tank line to go. I teed into my loader valve tank return.

 

[joea99]

Yes, just insert your valve where your backhoe would go. If two hoses for the backhoe, you need to find a place for the tank line to go. I teed into my loader valve tank return.

I may not be able to do that after all. On this model there is a lever, pull up for 3pt, down for backhoe. I'll need to check the hydraulics diagram to see if that shuts off flow to the backhoe hoses. I suspect it diverts it completely.

 

[Michael In Tennessee]

The ugly, but cheap, solution is to use your 4 in 1 lines.

 

[joea99]

The ugly, but cheap, solution is to use your 4 in 1 lines.

I'm all for cheap, as long as it works.

You're thinking of just putting it a diverter valve, hoses and quick connects?

 

[ericm979]

Doesn't Kubota make a rear remote kit for this tractor? A rear remote is ideal for controlling a hydraulic top link.
The factory remotes usually integrate better into the machine and are more ergonomic than home made. But it's possible to do your own as well. Put it in series between the loader valve and the selector for 3pt/BH.

 

[joea99]

Doesn't Kubota make a rear remote kit for this tractor? A rear remote is ideal for controlling a hydraulic top link.
The factory remotes usually integrate better into the machine and are more ergonomic than home made. But it's possible to do your own as well. Put it in series between the loader valve and the selector for 3pt/BH.

If so, I would surely consider one. If someone knows the Kubota numbers I would appreciate it. I'll search for them now on my own. I would not expect any dealers to know, given the age of the unit.

 

[joea99]

If so, I would surely consider one. If someone knows the Kubota numbers I would appreciate it. I'll search for them now on my own. I would not expect any dealers to know, given the age of the unit.

And sure enough, searching with the correct terms (top and tilt kit) finds B8032 as the kit part number. Looking at Messicks parts list it is one pricey set of toys.

 

[joea99]

And sure enough, searching with the correct terms (top and tilt kit) finds B8032 as the kit part number. Looking at Messicks parts list it is one pricey set of toys.

Astonished to find it is still listed and under $800. I tend to think I would be better off getting that than piecing together on my own.

Problem still remains (assuming it really is still available) I need to hook it into the hydraulics some where. The matching Kubota kit with valves, etc, is B8042 and is no where to be found. If someone can describe it and where it plumbs in, I can maybe scrounge up parts one by one.

 

[Michael In Tennessee]

I'm all for cheap, as long as it works.

You're thinking of just putting it a diverter valve, hoses and quick connects?

No. On the work side of the existing 3rd function valve, add male/female QD pairs. Disconnect 4 in 1 lines, add new lines to rear when needed. Won't be able to use 4 in 1 at the same time. You could do a diverter, but at added expense.

You can do a roll-your-own rear remote too. It should go: loader valve - existing 3rd function - new rear remote. Some tractors put 3rd function ahead of the loader valve though. I suggest you trace your existing hydraulic plumbing and diagram out possibilities. You then will know where your existing hydraulic supply, power beyond (if equiped) and tank lines go. Use a 2 or 3 lever valve of the appropriate flow rate. No sense doing this for just one remote.

 

[joea99]

I may have to content myself with aftermarket items. Think I want a couple spool valves for finer control of the box. What do I know?

Correct me if wrong, but I think I can remove the line going to the existing extra function block (from power beyond?) and input it to the spool valve and use a PB adapter in it and go from there to the existing extra function block. Rely on that for the return to tank, or would I have to find that line and T into it? Might be obvious if I had parts in hand. Well, it is past my bedtime.

Was told I need open center valves, 12gpm. But the FSM says B21 pumps just under 9, so an 11 gpm should do fine? Some say they have internal check valves for "load holding", is that sufficient or should the Link and arm have those checks on them as well?

 

[ericm979]

If you don't want to hook up both PB and tank ports from the new valve, you'll need to find a valve whose tank port is rated for your tractor's full pressure, usually around 2400 psi. Most are 500-750. This will limit your valve selection. You use the tank port as PB in this case and leave PB blocked (if it's even there). OTOH if you use a valve with both PB and tank, your tee into the existing tank line can be at one end of the line, where it comes out of the loader valve or where it goes into the transmission.

Some valves have handles that can be mounted in different positions. If you are mounting the valve on the fender, a common spot, you may want the handles to face forwards rather than up to get them closer to the loader joystick so you don't have to move your hand as far to operate them.

 

[Michael In Tennessee]

No need for the rear remote valve to be near the loader controls for rear remotes.

The only line that can be teed is a tank line.

Its is not necessary to go from the loader to the rear and back to the 3rd function. As long as the valves are in series and you have power beyond and tank ports where necessary, you are fine. 3rd functions generally don't have tank lines, so the output just goes to the input of the next valve.

Get us some pictures of the existing valves and lines and where the attach to the tractor.

 

[joea99]

No need for the rear remote valve to be near the loader controls for rear remotes.

The only line that can be teed is a tank line.

Its is not necessary to go from the loader to the rear and back to the 3rd function. As long as the valves are in series and you have power beyond and tank ports where necessary, you are fine. 3rd functions generally don't have tank lines, so the output just goes to the input of the next valve.

Get us some pictures of the existing valves and lines and where the attach to the tractor.

This is the existing third function valve, solenoid operated, on/off/on




This is the Bucket valve. The hose with RA fitting coming out back goes to the P port on the 3rd function valve.




Back of existing 3rd function valve. Port on right is marked L and goes back to tank (I think) looks like it came out of the bucket valve originally.
Port on left is marked P, hose comes out back of bucket valve.



Also attached are pictured of the ports on the solenoid valve. Seems I could just put a double (or triple) spool valve "in series" either before or after the solenoid valve, the removing the P hose, feed it to the spool valve "high" side and the "low/tank" side going to the solenoid P side. Or, feed the solenoid L side into spool valve assembly "high" side and the "return" from its "low/tank" side to the return to tank hose. I may have mangled the terms but hopefully it is clear enough.

All I really need to do is figure out where to mount stuff, make up any brackets and hoses needed and, play pen time.

 

[joea99]

I guess I need to modify my guestimations a bit. Looking up the HyVair valve specs it says the spool type is "A&B blocked P to T".

As mentioned I have only rudimentary current hydraulics knowledge, but, guessing this means there is no flow through the valve with the spools in center/idle position? If so that means if there is any chance of me working this out, the output of the Kubota bucket valve has to go to my Rube Goldberg setup, one that allows flow through it with spools "idle" via what ever they happen to call the "power beyond" port?

I suppose I could call the Parker outfit not that far away and discuss it with them as I read they are a HyVair dealer. At least I would not appear as ignorant having learned a bit from chatting here.

 

[Michael In Tennessee]

Link to valve spec please. A & b should be blocked to p & t when the valve is centered (idle). Whats the problem? P flows directly through the valve to T when idle. This is normal for a 3rd function and not a problem.

 

[Michael In Tennessee]

Question: How many hoses are attached to the loader valve? 6 or 7 (or different).

Question: Can you trace the fluid flow? Does it go: pump > loader > 3rd function > backhoe or pump > 3rd function > loader > backhoe.

Need picture of where supply hose comes out of tractor and where it returns.

 

[joea99]

Question: How many hoses are attached to the loader valve? 6 or 7 (or different).

Question: Can you trace the fluid flow? Does it go: pump > loader > 3rd function > backhoe or pump > 3rd function > loader > backhoe.

Need picture of where supply hose comes out of tractor and where it returns.

There are 7 hoses in that assembly. 4 go to/from loader, two metal lines at the bottom, one looks like it comes from the pump the other goes to the rear to the backhoe/3pt hitch stuff, looks like.

The one coming out the back goes to the 3rd function valve (the jaw/grapple of the 4 in 1). That looks like the PB (power beyond) port.

The existing 3rd function valve is HyVair D03s-2C-12D-35. Specs below.

View attachment 702150

 

[Michael In Tennessee]

That is weird. The three non-work ports should be Pressure, PB and tank. What do you think the rearward going hose do? Any chance you have any documentation on the tractor?

Where does the output of the 3rd function go?