Need some help with remote valves

[TRUST]

Hi, I am a new tractor owner and honestly don't know a lot about hydraulics. I have a Kubota 2620 with a FEL and a BH. I purchased a rear remote kit that I planned on adding myself(just cause I like to tinker) for running a grapple on the front bucket.

After looking at the instructions for the valve and the BH I'm getting confused. The BH is already on, however the valve instructions state its not compatible with the BH. I called my dealer and he said he called Kubota about that and says it will work. The instructions for the BH state that the BH must be removed before using the rear remotes. Something about using things downstream from the BH can cause damage? So now I am fairly confused as to what/how this works. All I want is to use a grapple on the front bucket. What I would really like to know is....what are my options? Options on where to connect to the tractor and options on different ways to operate it, even if I have to get a different type of valve. I can always return the one I have. It is a rops mount with a single lever.

Thanks, Joel

 

[kennyd]

Seems your question's a specific to the kit for your tractor, so I can't really help much unfortunately. Maybe you could check with another dealer?

 

[Farmerford]

Joel:

I am not familiar with your machine or the hydraulic system, but here is a wild guess. I assume the BH is frame mounted, so the TPH is not used when the backhoe is on. Therefore, the BH is the last hydraulic device in the system and as such exhausts directly into the reservoir. Thus, the BH valve does not need power beyond because there is never any pressure build up downstream of it (since there is no hydraulic device downstream).

The remote valve must connect downstream of the BH and would cause pressure in the BH exhaust circuit when used.

If that is the problem, it could be solved by converting the BH control valve to PB (if it is convertible); that normally requires a PB plug/insert and an additional hose to carry the high pressure fluid.

Sounds like the BH instructions assume the BH valve does not have PB.

I assume your remote kit is from Kubota and that the Kubota factory rep knows what he/she is talking about. I agree with Kennyd that you need to learn more from Kubota regarding the inconsistency between the BH instructions and the remote instructions. Perhaps you can get the dealer and factory guy on the phone at the same time.

If what you have does not work, all is not lost. It is fairly certain that you can install an additional control valve just downstream of your FEL. It is done all the time and there are many posts here on the various ways to do it.

 

[smooth_pilot]

I am learning about hydraulics, as well, but can confirm that Farmerford is on the right track. My L39 has two valves that have to be reset depending upon whether the BH is mounted or not. You can't operate the TPH and BH at the same time. I'm going to assume that your tractor is plumbed the same way.

If you want to use a rear remote to operate your grapple you would have to put those manual valves in the TPH position. The BH hydraulic hoses would have to be disconnected but you would not necessarily have to dismount the BH. Just be sure that the TPH draft control lever is locked in the "down" position. If the TPH lift arms come up when the hoe is mounted you will tear things up.

Kubota has an FEL hydraulic extension for the L39. Probably available for your tractor, as well. It puts an switch on top of the FEL control handle which operates an electrohydraulic valve in the PB circuit of the FEL control valve. Handy for grapple operation as you don't have to move your hand off of the FEL control level. Considering that all of the parts come in one box, the price is fairly reasonable.

 

[TRUST]

Joel:

I am not familiar with your machine or the hydraulic system, but here is a wild guess. I assume the BH is frame mounted, so the TPH is not used when the backhoe is on. Therefore, the BH is the last hydraulic device in the system and as such exhausts directly into the reservoir. Thus, the BH valve does not need power beyond because there is never any pressure build up downstream of it (since there is no hydraulic device downstream).

The remote valve must connect downstream of the BH and would cause pressure in the BH exhaust circuit when used.

If that is the problem, it could be solved by converting the BH control valve to PB (if it is convertible); that normally requires a PB plug/insert and an additional hose to carry the high pressure fluid.

Sounds like the BH instructions assume the BH valve does not have PB.

I assume your remote kit is from Kubota and that the Kubota factory rep knows what he/she is talking about. I agree with Kennyd that you need to learn more from Kubota regarding the inconsistency between the BH instructions and the remote instructions. Perhaps you can get the dealer and factory guy on the phone at the same time.

If what you have does not work, all is not lost. It is fairly certain that you can install an additional control valve just downstream of your FEL. It is done all the time and there are many posts here on the various ways to do it.

The TPH is not used while the BH is attached. It has a lock on the draft lever. Yes the kit is kubota kit, however some say it is not "factory", but nevertheless it does have a Kubota part number and I ordered it from the dealer. My dealer stated something to the effect that the Kubota rep did say that the BH does have a relief in it and the valve would work. For some reason which I have no answer to is why the valves directions state otherwise.

Seems like I read somewhere you can get a solinoid that diverts via a switch and allows the use of the loader bucked dump/raise to function to operate a grapple when the switch is made. If so, I was thinking that may be a better option as I would never have to take my hand off the loader control while using the grapple.

J.

 

[BotaBigot]

... My dealer stated something to the effect that the Kubota rep did say that the BH does have a relief in it and the valve would work. For some reason which I have no answer to is why the valves directions state otherwise...

I am far from being an expert on tractor hydraulics...but I've learned a lot reading TBN hydraulic posts for the last 2 years.

I believe FarmerFord nailed it with power beyond. When multiples control valves are plumbed in series in a hydraulic circuit, all but the last one needs power beyond. Whenever a control valve in the circuit is activated, everything from that function upstream to the pump is pressurized to pump pressure...which is OK when upstream valves are PB. But, some control valves are designed to be "standalone" (or last in series). Example: A log splitter valve. This type of valve expects the outlet to dump to the reservoir, and not have much back pressure (my 3PT splitter valve outlet is only rated 500 PSI). They're not designed to handle pump pressure. I'm guessing this is why your instructions read the way they do. As for the Kubota rep's "relief valve" comment...a relief valve protects the pressure side of the control valve (and associated cylinders, lines, seals, etc.), not the "tank" (outlet) side. If the downstream side is not rated to pump or relief pressure, then...

 

[TRUST]

I've done some studying and here is what I've came up with. My BH is fed from the PB from the loader valve. The outlet side of the BH goes to the 3PT inlet right by one of the 3pt lifting arms. It appears the BH valve has no PB.

The instructions on this remote valve would have you hook the inlet of the new remote valve to the PB of the loader valve( which is currently occupied), the outlet goes to a return to tank and the PB would go to the 3pt inlet. (that is currently occupied as well by the BH valve).

How would you hook it up?

Also I'm confused how the BH does not have a return to tank. It appears it only has and in and an out an the out feeds to the 3pt inlet. (I do understand the the 3pt cannot be used with the bh)

Can the return to tank line on the new valve be omitted if your using the PB outlet to feed to the next item in line? I guess I'm fuzzy on the return to tank thing, if your using a PB. But in the case of the BH it has neither the PB nor is it return to tank?

Joel

 

[BotaBigot]

Don't know why your BH doesn't use PB to the 3PT, only explanation I can think of is that since the 3PT can't be used simultaneously, the installed BH in effect becomes the last control valve in the system, with its outlet passing thru the inoperable 3PT "to tank."

Following the instructions, the new remote valve should be inserted in the system between the FEL and BH...if that's physically possible. It could also be installed before the FEL, but apparently not after the BH (if indeed, the BH doesn't have PB).

You can't omit the return to tank on the new valve. Cylinder exhaust side fluid needs a low pressure path (to tank) to work.

I would try to locate the hydraulic system schematic for your particular tractor (mine was in the Work Shop Manual). With that, and looking at the physical plumbing, I would find a location in the system that created the least inlet/PB/tank plumbing hassle.

 

[TRUST]

I think I got it figured out. Here is a link to my new post about this valve kit.

linky

 

[TRUST]

The remotes are finished.(lots of pics) Use the link in the above post to view.

Thanks for the help fellas!

Joel