
Adding second hydraulic valve.
#1
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Posted January 13, 2021 - 04:08 PM
#2
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Posted January 13, 2021 - 04:09 PM
- propane1 and Mark 149 J. have said thanks
#3
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Posted January 13, 2021 - 05:54 PM
There are many different configurations of valves. Until you know exactly what valves you have you or we are only guessing. If one valve is now working properly in the circuit I know of no way that installing a T after the pump would work. You have to start thinking in the terms of pressure and return lines. Most times the hydraulic control valves for hydraulic lift on a garden tractor are two way open center spring loaded which means you push to operate the cylinder in one direction and pull for the other direction. When you release the valve it returns to center and the cylinder is locked in its present position and the hydraulic flow is routed directly back to the return to tank line to relieve the pressure of the pump. In this position with the valve in the center position there would be no pressure available at your proposed T. Adding a second Identical valve by using a T in the pressure line would add a second open center relief to return and make sure nothing could work properly. I have a book ISBN number 935100-B. Industrial Hydraulics Manual. It explains all the standard valves and circuits in hydraulic systems. The people who have done hydraulics for years can often identify the different valves, circuits, and systems by sight but for a dummy like me it takes a lot of studying.
I still haven't gotten the hydraulic system on my JD 317 figured out. It has two control valves and a diverter valve controlling lift cylinder and front two front hydraulic ports which I have actuating lift and angle cylinders on a front blade. When operating the blade I sometimes get cross talk between the cylinders.
Don.
- Mark 149 J. said thank you
#4
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Posted January 13, 2021 - 08:56 PM
- Mark 149 J. and Nytractorguy have said thanks
#5
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Posted Yesterday, 06:07 AM
#6
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Posted Yesterday, 11:43 AM
I don't know how to add pictures to my reply but i am using the cub cadet control valves.
This should help explain how to load pictures
https://gardentracto...file-uploading/
#7
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Posted Yesterday, 01:25 PM
Second try, I bet your “crosstalk” happens when a cylinder bottoms out on its stroke. Back pressure can do funny things.
Have not investigated yet. At times when lowering the blade it contacts the ground and begins to change angle. I suppose the pressure goes up slightly when the blade makes contact. Always turns the blade to the right.
Don
- Mark 149 J. said thank you
#8
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#9
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Posted Yesterday, 04:36 PM
This is the valve I am using.
Has an actuator shaft on the left end. Push and pull on that shaft to see if it is self centering (spring loaded). Looks like the ports on the right end are for pressure and return. The A and B ports would go to the cylinder. Could be open center or closed center. If open center flow between the two ports on the right end should be free with the control being in the center position. Could also have a float position where there is an open flow between A and B ports. If you google the manufacturer and numbers you might be able to deturmin exactly what you have. Some valves can be set up for power beyond and some not. I have seen systems where an open center valve was wired into one position or the other to effectively bottom out the cylinder it controlled which forced the to go to the other valve. I am not capable of identifying a valve by sight and as far as I know valves that externally look identical except for the numbers can be greatly different in function and some can be reconfigured for different options. Again I suggest a trip to the library.
Don
#10
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Posted Yesterday, 04:40 PM
Found this in a quick google search. I know nothing about it and did not download it. It appears to be a digital copy of the book I have.
https://5a.avtomir21.ru/15.html
Don
#11
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Posted Yesterday, 05:03 PM
This is the valve I am using.
I plan to use that same valve on my Sears project!
#12
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Posted Yesterday, 05:04 PM
Found this in a quick google search. I know nothing about it and did not download it. It appears to be a digital copy of the book I have.
https://5a.avtomir21.ru/15.html
Don
That link never opened!
- secondtry said thank you
#13
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Posted Yesterday, 06:40 PM
That link never opened!
Don't open for me either. How I got there is google ISBN number 935100-B' go to the second page of the results, open the second item on that page. I just went back there and clicked download. It said I had to sign up and be a member. already having the book I didn't bother.
Don
#14
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Posted Today, 12:31 AM
Found what appears to be the same book but 4th edition on amazon relatively affordable. It may be available at the library. The name is Vickers Industrial Hydraulics Manual
Don
#15
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Posted Today, 05:06 AM
I do have one of these already on a tractor amd they return to center with no float. I blew thru one and it looks to be open in the center position for the inlet and outlet so look like daisy chaining is the way to go.Has an actuator shaft on the left end. Push and pull on that shaft to see if it is self centering (spring loaded). Looks like the ports on the right end are for pressure and return. The A and B ports would go to the cylinder. Could be open center or closed center. If open center flow between the two ports on the right end should be free with the control being in the center position. Could also have a float position where there is an open flow between A and B ports. If you google the manufacturer and numbers you might be able to deturmin exactly what you have. Some valves can be set up for power beyond and some not. I have seen systems where an open center valve was wired into one position or the other to effectively bottom out the cylinder it controlled which forced the to go to the other valve. I am not capable of identifying a valve by sight and as far as I know valves that externally look identical except for the numbers can be greatly different in function and some can be reconfigured for different options. Again I suggest a trip to the library.
Don
Edited by Nytractorguy, Today, 05:07 AM.
- KennyP said thank you