Almost there with grapple hydraulics...?

[stormpetrel]

My loader valve has a high pressure line from the hydraulic pump going into it. It has a return line which goes into a steel line that heads back to the pto. My tractor is a Yanmar 2210D.....am I wrong about the return going to the pto? Does it in fact return to the tank (transmission)?

When I talked to the people at Koyker about a power beyond sleeve for my loader valve, I was told NOT to "T" the return lines from the two valves together, that this would cause me to lose the pto while operating my grapple.

I was predicating my grapple hydraulics install on the graphic J.J. had very nicely posted. I need to be sure I'm installing stuff correctly BEFORE I complete it and fire the system up.

Here's a photo of the bottom of my loader valve. As you can see from the two large hoses, I only have high pressure from the pump, and a return line....
Also a link to the valve that Surplus center sold me to operate the grapple.https://www.surpluscenter.com/item.asp?catname=&qty=1&item=9-6701

I'm very confused to be told I shouldn't "T" the return lines together.....is this correct? Need help!!!!

 

[kennyd]

If you keep starting different threads you will only get more confused. Keep all the info in one thread please

 

[J_J]

You can tee the return hoses, as long as they are large enough as to not cause high back pressure. Use same size hose as the outlet.

 

[cycle_gator]

Not to disagree with the most knowledgable of the hydraulics group, but I do not think you want to Tee the "return" line. Based on what the guys from Koyker said, it appears to me the return line is acting almost like a power beyond. If I was in your shoes, with that Prince valve in hand to run the grapple, I would put that new valve in series in the return line, not as a Tee. So return line from loader valve goes to inlet on grapple valve, return on grapple valve goes to 3 pt/return line. That way, fluid is always flowing. If the using the loader does not cause issues for the three point, this set up would not either as you are, in essence, simply adding another valve section to the loader valve. This may not work quite as well as if the loader valve had PB as there will be a lessening of flow temporaily when the loader valve is actuated and the return flow is coming back through the opposite work port, but I will bet it will work well enough that you will not regret setting it up this way.
Added as an afterthought. Do, however, as JJ suggested, keep all the lines the same size as what is on the loader valve now.

 

[J_J]

Why do you think you can not tee the return lines. Here is a diagram.

http://www.tractorbynet.com/forums/...0053269-new-2-spool-valve-has-rd5000insts.pdf

 

[cycle_gator]

JJ:

I think we are talking past each other here. You certainly can tee into a return line for another return line. But I think what Stormpetrel has in mind is to tee into that line to get pressure to run the grapple valve. i.e, he would end up with a dead end or two tees into the return line, in which case the grapple would never work.

I suspect we are saying the same thing. If I interpret this correctly he is looking for a pressure supply for the new valve to run the grapple. So my solution is to just put the new valve in series in the return line.

 

[Gary Sweat]

Why do you think you can not tee the return lines. Here is a diagram.

http://www.tractorbynet.com/forums/...0053269-new-2-spool-valve-has-rd5000insts.pdf

If the grapple valve has a PB port then you can "T" the grapple valve return into the loader return line. If the grapple valve does not have PB port then the 3pt will raise the grapple valve return port pressure to whatever the 3pt is running at. Which will likely damage the grapple valve.

My loader valve shuts off the 3pt when operated. Don't they all work that way?

 

[cycle_gator]

If it is not damaging the current loader valve, it will not damage the grapple valve either, as they would be in exactly the same position. The grapple valve appears oversize for the task, given the rated flow, so I suspect it would not be in any worse shape than his current loader valve.

It may be better to use PB if it is available, but the folks at Koyker seemed like they really did not want to answer the question about the availability of a PB plug for the loader valve. From the pic it appears that side plug in question is an option for sideport entry (or exit in this case) for the return line without the additional chamber space necessary to create PB within the valve.

And, oh ya, it really is never as simple as it seems, well said!!

 

[J_J]

If the grapple valve has a PB port then you can "T" the grapple valve return into the loader return line. If the grapple valve does not have PB port then the 3pt will raise the grapple valve return port pressure to whatever the 3pt is running at. Which will likely damage the grapple valve.

My loader valve shuts off the 3pt when operated. Don't they all work that way?

If you have 8 GPM's, and are only using 4 GPM's for the cyl, then you have 4 left over for the 3pt. So, no you do not always shut off the 3pt when using the FEL.

 

[Gary Sweat]

If you have 8 GPM's, and are only using 4 GPM's for the cyl, then you have 4 left over for the 3pt. So, no you do not always shut off the 3pt when using the FEL.

Good point! My little pump only puts out 4 gpm so I am probably using it all for the loader. Dang, I need a bigger pump.