After reading in this forum about hydraulic top link, I am convinced that it is the way to go. I do have a question though. Is the cylinder a single or dual acting? Or the down pressure is caused by the implement weight? I have a dual control valve for the loader. I guess I would have install a T and add a standard control valve. Do I have other options?
Like JB said, the hydraulic top link is double acting.
As for plumbing in a new valve to operate the top link, your machine is most likely "open center" and your new valve will have to be plumbed "in series" or inline with your fel valve.
That means no Tee on a high pressure line.
Using a Tee to power another valve won't work because depending which valve you use, fluid would just flow through the other valve instead of the valve you are working. Your other valve is open allowing fluid to pass through it back to sump or tank. Fluid will flow in the direction of least resistance.
I am making an assumption that your fel valve is plumbed directly from you hyd pump?
If so, then your 3pt valve would be powered by the power beyond port on your fel valve. (I am assuming you have 7 lines to your fel valve).
One high pressure line coming into your fel valve from your hyd pump.
Four work ports where those lines go to the cylinders on your fel.
One exit line which returns fluid back to your tank or sump.
One power beyond line that goes to power your 3pt.
Note that some fel valves do not have that 7th power beyond port, they might use the exit or return to tank/sump to power the 3pt.
So, if you have 7 lines on your fel valve, you would need to:
1) Disconnect the power beyond line on your fel ... note where that line goes to (probably the 3pt valve)
2) Buy a new valve to power your top link.
It should be open center and also have a power beyond port on it. It will have an "IN" or P where the high pressure line connects to it. I will have an exit port and also a power beyond port. Depending on how many spools it has, it will have 2 ports for each spool to power a double acting cylinder. So a single spool valve would have only 2 work ports and a 2 spool valve would have 4 work ports on it. Sometimes there will be alternate exit (return to sump/tank) ports for ease of installation so don't be confused by that.
3) Install the new valve where you can comfortably operate it.
4) Run a line from your from the Power Beyond port on your fel valve (which you disconnected) to the "In" on you new valve.
That powers the new valve.
5) Run a line from the Power Beyond port on you New valve to the hose which you disconnected from your fel valve.
That will power whatever valve was being powered before from the fel valve. (Probably your 3pt)
6) Run a line from the exit or return to sump/tank on your New valve either directly to sump/tank, or you can Tee that one to an existing return to sump/tank line.
7) Run (2) lines from the work ports on your New valve to the new top link cylinder and you are done.
Now, if your fel valve only has 6 lines (no power beyond port), then:
1) Disconnect the exit or return to sump line on the fel valve.
2) Run a line from that exit port on your fel valve to the "In" port of your New valve to power it.
Then do the remaining steps above to finish.
Note again that even though you have only 6 lines on the fel valve (no power beyond port), I still recommend that your New valve have a power beyond port on it to whatever valve is down stream. It is always better to use power beyond ports to power the next valve in line.
I would also recommend getting at least a 2 spool New valve. That would give you an extra set of rear remotes to power other hydraulically controlled attachments. The plumbing to put that valve into your system is exactly the same as putting in a single spool valve. You would just have 2 more work ports to plumb to Quick Disconnects for future use.
Hope that helps..
Rob-
