adding a thumb to Kubota KX-018

[oldnslo]

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I am working on plumbing layout for relief valve

If that is a reducing / relieving valve you do NOT need a relief. The relief function of the valve maintains the reduced pressure by relieving any external load induced pressure to tank.

Sun also makes a body that eliminates all the extra plumbing for the reverse flow check. These bodies are the E2 series.

 

[love2havefun]

Well I tried adding the pressure assembly with external check valve, no luck! Simply too much plumbing on a small arm, I need to find assembly with build in check valve. I went to Sun Hydraulics site but I simply don't have the knowledge to figure out what I need.
I feel I need to do the following on one side of the auxiliary port:
- Reduce pressure to thumb closing ( top of cylinder) to 1800 from 3100
- Allow excess pressure in thumb cylinder to release back to tank when the bucket is curling up and pushing it up
If there is anything I have missed please feel free to advise
Your help is appreciated.
Thanks

 

[ptsg]

Well I tried adding the pressure assembly with external check valve, no luck! Simply too much plumbing on a small arm, I need to find assembly with build in check valve. I went to Sun Hydraulics site but I simply don't have the knowledge to figure out what I need.
I feel I need to do the following on one side of the auxiliary port:
- Reduce pressure to thumb closing ( top of cylinder) to 1800 from 3100
- Allow excess pressure in thumb cylinder to release back to tank when the bucket is curling up and pushing it up
If there is anything I have missed please feel free to advise
Your help is appreciated.
Thanks

Excavators usually come ready for what you want to do. They have relief valves on the work ports of the auxiliary valve to allow the extra pressure to relieve to the tank.

Basically you just need to connect the thumb to the auxiliary circuit and then adjust the work port pressure relief valves at the valve bank.

After looking at your previous picture of the valves, it's a pain to check anything like that but I would try to look around a bit better.

 

[love2havefun]

Excavators usually come ready for what you want to do. They have relief valves on the work ports of the auxiliary valve to allow the extra pressure to relieve to the tank.

Basically you just need to connect the thumb to the auxiliary circuit and then adjust the work port pressure relief valves at the valve bank.

After looking at your previous picture of the valves, it's a pain to check anything like that but I would try to look around a bit better.

That's the problem, there is no adjustment, the auxiliary circuit get's same a rest at 3100psi. I need 1800 so that the bucket will overcome the thumb when you curl it

 

[ptsg]

That's the problem, there is no adjustment, the auxiliary circuit get's same a rest at 3100psi. I need 1800 so that the bucket will overcome the thumb when you curl it

No work port relief valves on the auxiliary valve? That's odd though. Do you have a hydraulic diagram?

EDIT: Just checked the parts diagram on the KX-018-4 on Messicks and it doesn't have it either. That's a bit lame from Kubota. Most excavators have relief valves at the work ports.

 

[love2havefun]

No work port relief valves on the auxiliary valve? That's odd though. Do you have a hydraulic diagram?

EDIT: Just checked the parts diagram on the KX-018-4 on Messicks and it doesn't have it either. That's a bit lame from Kubota. Most excavators have relief valves at the work ports.

I do not have hydraulic layout. I have checked hydraulic pressures with gauge and they are at 3100 like the owners manual says. It's not a big deal I just need assistance with pressure regulator / relief valve

 

[oldnslo]

If the link below works it is the page for Sun Bodies with cavity for reducing reliving valve and free flow check. Multiple ports styles and sizes to choose from.


https://www.sunhydraulics.com/model... degree with reverse flow check - reducing"]}

 

[love2havefun]

If the link below works it is the page for Sun Bodies with cavity for reducing reliving valve and free flow check. Multiple ports styles and sizes to choose from.


https://www.sunhydraulics.com/model... degree with reverse flow check - reducing"]}

I just added a thumb, the thumb manufacturer ask痴 that the hydraulic pressure be set to 1800 psi (the auxiliary circuit it plugs into is currently 3100psi) so that when you curl the bucket the bucket will overpower the thumb and both will move up accordingly. I looked at the bank of hydraulic valves but don稚 see any adjustment on the one that works the auxiliary circuit.
Then I reviewed a Kubota site to find that there are 田aps you remove to find spring and shims ,I would like more information on the shims please.
I am trying to lower not increase pressure but then need to increase pressure back to 3100 psi when I hook up post hole auger.
Is there a 田ap that has an adjustment rod/screw that can be adjusted without taking things apart? If you have details on this is appreciated so I can order from someone.
Thanks for your help

 

[Seven Gables]

Just wondering if you did in fact find this cap and the shims and spring on your auxiliary valve? If so just take one shim at a time out and re test your hyd pressure to see how much each shim removed reduces the pressure.

 

[love2havefun]

Just wondering if you did in fact find this cap and the shims and spring on your auxiliary valve? If so just take one shim at a time out and re test your hyd pressure to see how much each shim removed reduces the pressure.

I spoke with another Kubota dealer who advised me that Kubota has a valve available for this that vents excess pressure over to other side of cylinder and they use it on their thumb installations. OMG I have many hours into this with no success to hopefully have found a solution. I have ordered the valve and will install in when I receive. I will let you know once done.