L**40 rear hydaulic pressure

[J_J]

Although this situation is different than most by the fact that we are seeing a picture of a gage at 3200 psi. Not saying that it can not do that, but I did not see the test, and what all was done.

I am curious why a video was not made showing the gage with tractor running with voice annotation, and someone going through all the motions of a test.


A 15 min test using all the hyd on the tractor, could be exercised to show all the variables. What did you do, and what were the results.

We have asked a lot of questions, and I am not sure they have been answered.

oldnslo, my self, and others have ask some detail questions to complete certain task to seek out answers and try to resolve this situation.

Is there any reason that you can not make a short video, working all the hyd in order to show the action and the result of that action.

I think I would have inserted a flow and pressure meter in the circuit to see what was happening.

Where is the test for the 3pt, or is it using the FEL relief settings. When you did the pressure test at the remote and deadheaded the valve, which relief valve relieved the pressure, or did any valve relieve the pressure.

How long did you deadhead the pump to read the 3200 psi.

If the gage was left in place in a tee at the IN port, the gage would show all results of any hyd action through the hyd system. If you have QD's on the remote, and activate the valve, the first relief valve in the flow path should protect the complete system.

Are all QD's engaging properly?

Are there any fittings with flow restrictions used, with out knowing.

If you are cautious about using the tractor with 3200 psi, you could put an external relief across the pump .

Is there anybody that thinks that Kubota would design a hyd system with out a relief valve to protect the hyd pump, or a circuit that would cause the pressure to exceed the relief valve. Relief valves hardly fail closed. So if the hyd flow path of the fluid is passing the relief valve, it should work as long as the tractor is running.

Yes, of course a hyd pump with out a relief valve will try and develop pressure until something breaks, or the pump bypasses internally. The pump should never get to that pressure if the first relief valve setting is working correctly, which was I believe was 2550 psi.

If this tractor has regen, how would this affect the pressure.

Is it possible that you could have reversed the remote valve hose connection, or is it hard line or internal connection.

 

[oldnslo]

JJ,
this is the schematic that 4shorts posted on page 5. It shows the system relief Item 16 as the first item from the pump item 15. It also indicates that the relief item 16 is contained within the FEL control valve item 14. This schematic also shows the second pump being totally separate circuit.

Kuboman has stated everything is hard plumbed.

In looking at the schematic, none of what Kuboman is seeing is logical or makes any sense. The fact that his tractor is doing this and the tractor at the dealership is doing this sure makes me wonder what could cause this.


Kubo, you do realize it close to January 1st and not April 1st which is April fools don't you??:confused2:

Roy

 

[4shorts]

When I did the test at the rear remote on mine I asked Kubotaman how he wanted it done. He said he did his at idle and engine warm. I did it that way as well. When I attached the guage I pulled the aux lever until I heard the strain come on the system and let off. I'm sure at a higher RPM and a longer stay on the lever I could have bumpted the pressure up a bit more. I kind of stayed out of this conversation due to being on holidays and the fact the guys posting on the subject know far more about it than I ever will.

The OP should be very thankfully you guys are so determined to help him sort it out. Good stuff :thumbsup:

Is the warranty period expired on this machine ?

 

[J_J]

Seems like there is something different about the dashed line and a solid line associated with a relief valve item 16. Is not one of them a pilot operated relief valve?

If it does indeed need a pilot pressure, where is it coming from?

I thought I saw some other relief valves in some of the other units .

 

[kuboman]

When I did the test at the rear remote on mine I asked Kubotaman how he wanted it done. He said he did his at idle and engine warm. I did it that way as well. When I attached the guage I pulled the aux lever until I heard the strain come on the system and let off. I'm sure at a higher RPM and a longer stay on the lever I could have bumpted the pressure up a bit more. I kind of stayed out of this conversation due to being on holidays and the fact the guys posting on the subject know far more about it than I ever will.

The OP should be very thankfully you guys are so determined to help him sort it out. Good stuff :thumbsup:

Is the warranty period expired on this machine ?

Yes I am very grateful for all the determined help here. I have and will try to answer all questions.
As for a video, I will see what I can do. I am alone with this and it is a 2 man job to get a video that would show anything. Bear with me.

 

[oldnslo]

Seems like there is something different about the dashed line and a solid line associated with a relief valve item 16. Is not one of them a pilot operated relief valve?

If it does indeed need a pilot pressure, where is it coming from?

I thought I saw some other relief valves in some of the other units .

JJ,
Don't know if this is a Direct Acting or Pilot operated relief. Either way it is sensing pressure right at the inlet of the relief valve per the schematic.

Other reliefs are in the 3PH Position Control Item 1.

Roy

 

[oldnslo]

The OP should be very thankfully you guys are so determined to help him sort it out. Good stuff :thumbsup:

Is the warranty period expired on this machine ?

4shorts,
your posting of the scheamtic is invaluable and many thanks.

Now back to :mur::mur::mur:

 

[J_J]

Yes I am very grateful for all the determined help here. I have and will try to answer all questions.
As for a video, I will see what I can do. I am alone with this and it is a 2 man job to get a video that would show anything. Bear with me.

A suggestion for the video would be to install the gage in a tee before the FEL if possible, and aim and focus on the gage only, and then activate the levers to show all the relevant test. Annotate with voice as you select the different lever or valves, and explain as you show and tell.

If the hyd we are discussing now are from the same pump, and supply the FEL, remote valve and 3pt valve, the one gage will suffice.

 

[oldnslo]

A suggestion for the video would be to install the gage in a tee before the FEL if possible, and aim and focus on the gage only, and then activate the levers to show all the relevant test. Annotate with voice as you select the different lever or valves, and explain as you show and tell.

If the hyd we are discussing now are from the same pump, and supply the FEL, remote valve and 3pt valve, the one gage will suffice.

Good advice on gauge placement. problem is with everything being hard plumbed installing a tee is next to impossible. Tried looking at the pictures both Kubo and 4shorts posted but was unable to see if there was any plugs in the valve bodies that might be pressure ports.

Roy

 

[J_J]

Roy, I sent you a PM.