Rear Hydraulic valve question

/ Rear Hydraulic valve question #1  

BeezFun

Elite Member
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Jul 1, 2009
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IL
Tractor
Kubota B2710
Got my Prince 3 spool valve and put it together. Referring to page one of attached instructions, I thought I ordered it to come with an open center plug (option 1), but it came with a power beyond plug (option 2). I guess I have to call and get an open center plug, and use it to replace the power beyond plug that it came with. I still need to have the hoses and fittings made up at the local hydraulic place. Would they have the plug that fits this?
thanks
 

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  • TractorHydraulicValveInstructions.pdf
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/ Rear Hydraulic valve question #2  
Got my Prince 3 spool valve and put it together. Referring to page one of attached instructions, I thought I ordered it to come with an open center plug (option 1), but it came with a power beyond plug (option 2). I guess I have to call and get an open center plug, and use it to replace the power beyond plug that it came with. I still need to have the hoses and fittings made up at the local hydraulic place. Would they have the plug that fits this?
thanks

They should have a plug. Is there a chance that the plug is the same size for both ports? Literature shows #8 SAE ORB for the power beyond.

Roy
 
/ Rear Hydraulic valve question
  • Thread Starter
#3  
Thanks, I have to take the valve with me when I get the hoses made, so I'll ask them to plug it.
 
/ Rear Hydraulic valve question #4  
Why don't you want to use the PB plug?
 
/ Rear Hydraulic valve question
  • Thread Starter
#5  
Why don't you want to use the PB plug?

Because it's not a plug, but that's what the drawing calls it. I don't know the right hydraulic jargon, but I'd call it a port extender- it's threaded to accept a fitting to support more hydraulic devices downstream. So I assume if I connected the supply to the inlet, and the return to the outlet, hydraulic fluid will come shooting out the hole in the "plug".
 
/ Rear Hydraulic valve question #6  
That is a big 10-4 on that one. Old Faithful has nothing on an open PB port
 
/ Rear Hydraulic valve question #7  
Because it's not a plug, but that's what the drawing calls it. I don't know the right hydraulic jargon, but I'd call it a port extender- it's threaded to accept a fitting to support more hydraulic devices downstream. So I assume if I connected the supply to the inlet, and the return to the outlet, hydraulic fluid will come shooting out the hole in the "plug".

Yes, that is correct, and that PB line is what you would connect to the 3PH on a typical valve install on a Kubota tractor.
 
/ Rear Hydraulic valve question #8  
Yes, that is correct, and that PB line is what you would connect to the 3PH on a typical valve install on a Kubota tractor.

That's right, you guys with Open Center have to hook back into the 3PH when your done. I keep forgetting that and it seems so wierd to me since everything I have is Closed Center.
 
/ Rear Hydraulic valve question
  • Thread Starter
#9  
Yes, that is correct, and that PB line is what you would connect to the 3PH on a typical valve install on a Kubota tractor.

I'm confused. My kubota has an auxilliary hydraulic connection in the rear of the tractor on the side of the transmission, it provides a supply connection, and a return connection. I plan to connect the valve I bought to that auxilliary connection. I'm not tapping into the 3pt hydraulics. So I just use the inlet and outlet on the valve I bought, I don't need to do anything with PB. True?
 
/ Rear Hydraulic valve question #10  
most HST kubota tractors has nearly everything "tapped in to each other" for example, my BX has pby port in back of tractor and out with extra tank return. Without the pbyd plug, I cant use the 3 pt hitch same time fluid going through the new add on prince valve. From my point of view, open center plug and power beyond plug on the kubota tractor is essentianly the same thing. I could be wrong somewhat here, but this is how I see it and understand it.
 
/ Rear Hydraulic valve question #11  
...I'm not tapping into the 3pt hydraulics...

Would it not be the case where the loader valve's pb port is already connected to the 3PH ?
 
/ Rear Hydraulic valve question
  • Thread Starter
#12  
most HST kubota tractors has nearly everything "tapped in to each other" for example, my BX has pby port in back of tractor and out with extra tank return. Without the pbyd plug, I cant use the 3 pt hitch same time fluid going through the new add on prince valve. From my point of view, open center plug and power beyond plug on the kubota tractor is essentianly the same thing. I could be wrong somewhat here, but this is how I see it and understand it.

That's helpful, I think I see what I'm confused about.
On the valve there's an outlet and a power beyond port. I understand that if the valves are all in neutral position there is open flow from the inlet of the valve out the pbp, so you can power something downstream. When does anything come out the outlet of the valve, and what is it for? I thought if I plugged the pbp, that the outlet valve would also carry full pressure flow back to the auxilliary block when the valves are in neutral position. I think that's not correct.
 
/ Rear Hydraulic valve question #13  
That's helpful, I think I see what I'm confused about.
On the valve there's an outlet and a power beyond port. I understand that if the valves are all in neutral position there is open flow from the inlet of the valve out the pbp, so you can power something downstream. When does anything come out the outlet of the valve, and what is it for? I thought if I plugged the pbp, that the outlet valve would also carry full pressure flow back to the auxilliary block when the valves are in neutral position. I think that's not correct.

PLEASE correct me if I am wrong.
A CC plug is for a closed center system, which means that you have to have a variable displacement pump.
A OC plug means that the system is open center, and it at the end of the line meaning all oil not intercepted when a spool is worked will go to TANK, which you are calling the "outlet."
A Power beyond plug means that you have more work to do down stream, and this plug is a means of getting the oil there without overpressurizing the valves "TANK" port. Most Tank ports cannot take full pressure.
 
/ Rear Hydraulic valve question
  • Thread Starter
#14  
PLEASE correct me if I am wrong.
A CC plug is for a closed center system, which means that you have to have a variable displacement pump.
A OC plug means that the system is open center, and it at the end of the line meaning all oil not intercepted when a spool is worked will go to TANK, which you are calling the "outlet."
A Power beyond plug means that you have more work to do down stream, and this plug is a means of getting the oil there without overpressurizing the valves "TANK" port. Most Tank ports cannot take full pressure.

I believe you're correct. The confusion (I think) is due to the fact that my model (B2710) has a rear auxilliary hydraulic connection, but I'm not confident I know what it's tapped into. It's possible it provides connections for a supply and a return. So on the control valve I bought, I would run the outlet from the control valve back to that connection because it goes to the hydraulic tank. And I should plug the power beyond port on the control valve.
On the other hand, it's possible that auxilliary connection is a tap into the supply side, in which case I need to plumb the valve's pbp back to the auxilliary connection. I'll research this more tonight when I get home.
 
/ Rear Hydraulic valve question #15  
I'm confused. My kubota has an auxilliary hydraulic connection in the rear of the tractor on the side of the transmission, it provides a supply connection, and a return connection. I plan to connect the valve I bought to that auxilliary connection. I'm not tapping into the 3pt hydraulics. So I just use the inlet and outlet on the valve I bought, I don't need to do anything with PB. True?

False. Please look at your owners manual page 39 or there about.

You will see that power beyond is involved, and you MAY need three lines, not two. Further, you may need a pressure relief device, depending on where you are connecting.

If I understand correctly, mid WILL require three lines, and a relief device, and rear MAY require three lines if there is a relief device in your Prince valve stack. I will reread this and ponder, and if I think I am wrong, I will re-post. Hopefully, others will chime in and confirm or deny as well.

Please study the page from AN owner's manual carefully. If you can verify it does match that in YOUR owner's manual, we are in business!
 

Attachments

  • B2710-B2910-B7800.pdf
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/ Rear Hydraulic valve question
  • Thread Starter
#16  
False. Please look at your owners manual page 39 or there about.

You will see that power beyond is involved, and you MAY need three lines, not two. Further, you may need a pressure relief device, depending on where you are connecting.

If I understand correctly, mid WILL require three lines, and a relief device, and rear MAY require three lines if there is a relief device in your Prince valve stack. I will reread this and ponder, and if I think I am wrong, I will re-post. Hopefully, others will chime in and confirm or deny as well.

Please study the page from AN owner's manual carefully. If you can verify it does match that in YOUR owner's manual, we are in business!

Talked to the service dept at the dealer. The power beyond port from my valve stack needs to be connected back to the auxilliary block. And I do need a 3d line because I have a pressure relief on the valve stack. The return port location is shown on page 40 of the manual you kindly provided, which matches mine. It's still not clear to me how you know from that diagram in the manual that power beyond is required to go back to the block, but I'm not that familiar with hydraulics. Thanks for your help, I think everything you say is correct.
 
/ Rear Hydraulic valve question #17  
Talked to the service dept at the dealer. The power beyond port from my valve stack needs to be connected back to the auxilliary block. And I do need a 3d line because I have a pressure relief on the valve stack. The return port location is shown on page 40 of the manual you kindly provided, which matches mine. It's still not clear to me how you know from that diagram in the manual that power beyond is required to go back to the block, but I'm not that familiar with hydraulics. Thanks for your help, I think everything you say is correct.

I am glad your getting specific help for your machine. I can answer this for you though:

When does anything come out the outlet of the valve, and what is it for?

In a PB equipped valve, only "waste oil" from the work ports goes out the OUT or T port.
 
/ Rear Hydraulic valve question
  • Thread Starter
#18  
In a PB equipped valve, only "waste oil" from the work ports goes out the OUT or T port.

Thanks, I've been reading some online hydraulic info and I think I've got it sufficiently figured out to hook this up. Will post pictures of what I end up with.
 
 
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