Rear Remotes and Single Acting Cylinders

[oldnslo]

Could one not connect the hose from the single cyl to the float port on a valve.

If you were to push the lever to the down position, the relief will activate, but if you go into the detent float mode, the cyl should move with the ground level with no adverse action.

Yes, this would allow a SA cylinder to float.

 

[SPYDERLK]

Well i have a single acting cylinder on my post hole hydraulic assist and it did not work on the rear hydraulics.

The fix was a simple part that screws into the rear HST filler spout, and the single acting cylinder line dump plugs into this.

Its the same part they use for backhoes.

Part was like $24.00 from my Kioti dealer PLUS the female hyd connector end that i already had. And took about 10 minutes to install.

My dealer told me this is necessary any time a single acting cylinder is used.

It should have worked without it if you lifted the 3ph at the same time you valved "retract" to the remote. Tihis pressurizes the vacant/closed retract QD and since it wont flow, the relief valve vents to tank. The extend port on the remote valve is also vented straight to tank while in retract position, and doesnt resist lifting the 3ph.
.. I dont know why that didnt work for you, but I know the relief valve on my old JD doest sound like it appreciates it. No problem at all on the more modern tractors.
larry

 

[grsthegreat]

Well i dont know what to tell you all, but i tried plugging my hoses into every different rear port i had and i could not get the single acting cylinder to retract....especially when i lifted the 3 point.

With the return line that my dealer had me install, it work like it was designed to do.

JJ, the fitting and connector that the dealer had me add goes to one of the hoses on the post hole assist cylinder, and the other hose from the cylinder goes to the upper rear remote port from my NON-detente style rear remote controls. When i pull up on the lever, the single acting cylinder extends, and as i lift the 3 point, it collapses the cylinder. This way i dont have to control the rear remotes at all during lifting of the 3 point.

 

[grsthegreat]

... I am confused about the 2 hoses on a single acting cylinder tho.
larry

there is a block/manifold on the cylinder with 2 hoses.... see pic

 

[grsthegreat]

what i dont understand is how a cylinder with only 1 hose would ever work. It would extend but how would it ever retract???

 

[oldnslo]

what i dont understand is how a cylinder with only 1 hose would ever work. It would extend but how would it ever retract???

Gravity or some other external force. Lots of older farm equipment and FELS worked on SA cylinders.


On your PHD does your tractors directional valves tank port (power beyond)feed the 3PH? If yes this would explain why the SA cylinder would not retract while lifting the 3PH. Other wise with out knowing how your tractor is plumbed (I.e. hydraulic schematic) we can only guess as to why something works or does not work.

Roy

 

[grsthegreat]

Gravity or some other external force. Lots of older farm equipment and FELS worked on SA cylinders.


On your PHD does your tractors directional valves tank port (power beyond)feed the 3PH? .

Roy

I have NO clue at all.....

 

[J_J]

I think I may have the answer, If that hyd block on the cyl has a shuttle valve/check valve, that closes off the hose going to the tractor 3pt, the cyl will raise. When the 3pt is used, the pressure is released from the shuttle valve and the fluid escapes to the reservoir. Plausible but not positive.

One valve raises the cyl and another valve lets it down with a load down force.

Shuttle valve
-to isolate one part of a system from an alternate part of circuit.

http://www.valvehydraulic.com/hydraulic-shuttle-valves.html

 

[SPYDERLK]

Well i dont know what to tell you all, but i tried plugging my hoses into every different rear port i had and i could not get the single acting cylinder to retract....especially when i lifted the 3 point.

With the return line that my dealer had me install, it work like it was designed to do.

JJ, the fitting and connector that the dealer had me add goes to one of the hoses on the post hole assist cylinder, and the other hose from the cylinder goes to the upper rear remote port from my NON-detente style rear remote controls. When i pull up on the lever, the single acting cylinder extends, and as i lift the 3 point, it collapses the cylinder. This way i dont have to control the rear remotes at all during lifting of the 3 point. [--It should have worked without it if you lifted the 3ph at the same time you valved "retract" to the remote].

Sorry, long interrupted edit. [Iv repositioned the post] > ... I am confused about the 2 hoses on a single acting cylinder tho. I guess what youve done is put one of those hoses [the retract] venting to tank. I dont see how that alone would allow you the raise the 3ph w/o operating the remote simultaneously ... UNLESS its a relief valve Tee'd, instead, off the extend hose, then to the tank. Looking back at the last picture you posted that could be it.
larry

 

[MtnViewRanch]

This is one of the BIG reasons that you use a kit designed to work for a PHD down pressure kit. It just is not worth the risk or the hassle to save literally a few dollars to build this kit on your own. And what may or should work sometimes has things actually working against themselves and the stronger piece wins while the weaker piece ends up failing at some point. Always better to have things work together vs against each other with the stronger piece prevailing.

As far as having the 2ND bleed off hose connected to a separate valve locked into float position, that is exactly what I do on my 7520. But you need to have 2 available controls to be able to do that and have no worries. Yes you could physically do it with one valve that has float position, but you would always have to be 100% sure that it was in the right position each and every time that the boom was raised when the down pressure had been used. This would be a real pain and at some time I'm sure that something BAD would end up happening. I have 3 rear remotes on that tractor and use the 1st remote that normally gets used for my hydraulic top link as the return to tank port. I bungee the lever into float position so that I don't worry about it getting knocked out of the float position. I use the 3rd remote for the down pressure hydraulic and I use the 2ND remote for the side link to be able to adjust the PHD to be plumb if I am on a hill.

I hope that all of this helps or clarifies this situation for someone.