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 | KCoburn
Join Date: Jul 2003 Posts: 2 West Branch, Iowa 
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2002-06-02 39252
I've equipped my Kubota L3600GST with hydraulic top and side links. The tractor came with a single rear remote, so rather than go through all the grief of plumbing with individual valves, I piped a triple electric solenoid valve to the single rear remote. I don't mind having to select a switch to direct power to the cylinder of choice. But my side link leaks down allowing the implement to slowly pitch down on one side. Means I have to hit the remote lever about once a minute to keep the implement level. It'll even drop a little without an implement attached. I noticed this when I installed the first side link cylinder (Tisco). I returned it and they sent me a replacement. Same thing. Is the leakdown the fault of the cylinder or is it possible that fluid is leaking by the valve? I've moved the side link to all three positions on the solenoid valve and it seems to make no difference. Thanks in advance for your thoughts.
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| TomG
Join Date: Feb 2002 Posts: 5406 Upper Ottawa Valley 
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2002-06-03 39260
A cylinder's control valve sure can cause leak down. an easy test if the connection uses quick-connect fittings is to level the hitch and then disconnect the lines. Assuming that there's only one problem, if it leaks down while disconnected from its control valve, then the problem is the cylinder, otherwise it's the valve. Some control valve assemblies have adjustable relief valves that could allow leak-down if broken or out of adjustment.
I have to guess how the hydraulic multiplier works. I imagine it's a three-way diverter type under solenoid control. Such a valve should give any one line open and the other two closed. There probably are pressure relief valves on each line. I'd discount the multiplier as the problem, because ultimately it’s the control valve that closes both lines to a double acting cylinder when the valve is centred. I do wonder if the leak-down still occurs whether or not the multiplier is selected for the tilt cylinder? If the leak-down sopped when the tilt wasn't selected, then the control valve would be suspect.
If the loader doesn't leak down, it would be very handy to connect the rear outlet hoses to one of the loader valves to see if the leak-down stops. Again, quick connects are handy. One thing that may confuse finding the problem is that the tilt leaks down while the top-link doesn't. That might suggest the tilt cylinder as the problem, because the control valve should affect all three lines. However, some implements place very little load on the top link when the implement isn't working. The top link might not leak down simply because there's very little load.
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| KCoburn
Join Date: Jul 2003 Posts: 2 West Branch, Iowa
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2002-06-03 39264
Tom,
Thanks for the tips. It hadn't occurred to me that the control valve could be the culprit. Your suggestion-disconnect the couplers to the side link-was a good one. It should allow me to determine whether or not the cylinder is at fault.The side link cylinder does leak down, even when that port isn't selected. The top link will also leak down, but very slowly and not enough to be the irritation that the side link is. It's pointing toward the control valve, isn't it? I'll bet, as you suggested, that there's less load on the top link so it's not so apparent that it's also leaking down. I truly appreciate your help. ....
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| TomG
Join Date: Feb 2002 Posts: 5406 Upper Ottawa Valley
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2002-06-04 39290
Thanks for the kind words. I did have an additional thought after I posted.
About the only way I can see that the hydraulic multiplier could be the problem is if there could be leak through from one line to another. Someplace inside the multiplier there should be an area that is common to all three output lines. Poor sealing in this area could allow oil under pressure from line to enter the other output lines. If that's what's going on, then leak down of the side-leveler cylinder would be accompanied by extension of the top-link cylinder (provided the top-link load is less than the side-link load). The extension might be noticeable if the top-link cylinder is a larger diameter than the side-link cylinder. A test for this theoretical problem would be to disconnect the top-link from the multiplier and see if the leak-down stops.
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 | Art White
Join Date: Jan 2000 Posts: 6898 Waterville New York
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2002-06-04 39293
Depending on the type of valve it might be the problem. If you don't have a check valve on the line your problem can happen with any valve that carries a load and is not uncommon. You might call the company as it sounds as yours is leaking down rather fast on that cicuit. ....
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