Loader Leaks Down

[jimainiac]

I have a Kubota L3830 with the LA723 loader. Ever since it was new I noticed that the loader would not hold it's position and would gradually leak down. I even called the dealer to ask about it and they said it was normal. Most of the time it doesn't matter, but sometimes I use it for a platform with the pallet forks on. It's aggravating when it won't hold it's position, and I'd like to fix it. I thought the problem was probably in the control valve, but I have read several posts relating to this problem and knowledgeable people said it's usually one or both of the lift cylinders. In one post, Kennyd suggested a way to diagnose the problem. He said to retract the cylinders all the way, then remove the line at the butt of the cylinder and move the control to try to retract the cylinder again. If the cylinder is leaking fluid will come out. If the cylinder is okay nothing should come out. I hope I have that right, because that's what I just did, and nothing came out from either cylinder. I did them one at a time. Assuming that was the right procedure, and that result, I guess that the leakdown must be occuring in the control valve. Does anyone have any suggestions or thoughts?

 

[J_J]

Join the crown, I think we all have this problem. It ranges to leak down over a week to over night, to where you can watch it drop in an hour or less. May new seals, different valve, a high pressure ball valve to shut off fluid coming back to valve. Is both the lift cylinders and the tilt cylinder doing the same thing.

 

[jimainiac]

If it took the loader a week to leak down I don't think I'd mind, although the 3PH never drops. I don't really see it moving, but in, say, 15-30 minutes or so it'll be down inches. The bucket seems to stay put, it's the loader arms that go down.

 

[Wayne County Hose]

Measure exactly how much it comes down in one hour with a full capacity load. Then, go to the dealer and ask him what Kubota says is acceptable, in print, not verbally. Then tell him you want it repaired. If you guys all started making a fuss about this rather than accepting it, it would force these manufacturers to start installing a higher quality valve.

 

[J_J]

Measure exactly how much it comes down in one hour with a full capacity load. Then, go to the dealer and ask him what Kubota says is acceptable, in print, not verbally. Then tell him you want it repaired. If you guys all started making a fuss about this rather than accepting it, it would force these manufacturers to start installing a higher quality valve.

They are probably not going to do anything about it unless it is severe, Maybe change out the valve, to the tune of $500 or $600, plus labor, and they will continue doing that until the tractor owner is broke. Sure they will tell you the leak down is normal, and they can probably prove it by raising all the loader arms at the dealership and see how many are still up the next day. If the manufacture produce a valve with better tolerances, it will cost more for sure. If they had to build to mil spec, you know it is going to cost you. Every item is tested, not just one out of a thousand. Why, might you say. Because you don't want that nose wheel dropping out of it's storage bay in flight, or that flap to extend at the wrong time.

If you don't want to spring for a new valve, you could put a pilot operated check valve in-line, which will hold a cylinder until you activate the pilot and release the fluid.

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[john_bud]

Wayne is correct. You have a leaky valve.

Not all are junk. Mine will stay up with an empty bucket for more than 2 months. It will drop from full height by 4-5 foot over that time, but that's fine by me!

It could be as simple as o-rings in the valve leaking. Go to the dealer and if they won't fix it (and they probably won't), have them give you a parts breakdown on the valve with the sizes of the o-rings listed. You can either do a straight replace or "upgrade" with quad rings. Like an o-ring, but with 2 seal surfaces. Still cheap.

jb

 

[jimainiac]

Thanks for the ideas guys.

Wayne County- Your idea would be a good one if it was still new. Unfortunately I didn't pursue it then, and now it's five years old and going on 700 hrs.(Time does fly when you're having fun.)

J J- A valve like that, or even a ball valve inline, would be a last resort.

John Bud- If my loader stayed up that long we wouldn't be having this conversation! I would like to fix the valve myself, if possible. Unfortunately, the loader valve isn't covered in the shop manual. I'll try to get my dealer to explain how to fix it and get the parts. I never heard of a quad ring - I'll ask them about that. Doesn't seem like tearing into the valve should be rocket science - I hope.

 

[Wayne County Hose]

I would almost bet that this valve does not have o-rings in it. Honestly, just my humble opinion here, I believe that the leakdown you guys experience is not normal at all. It may be normal for your CUT's, but in the hydraulics industry, it is not normal. Leakdown is usually checked with a full capacity load and you measure the drift in a certain time period. In the forklift industry, .5" in 15 minutes is too much. I have seen many a hydraulic system that experienced exactly zero drift in a month. If I ever bought one of these things, I would be their worst nightmare.

 

[Kfbeal]

What does it mean if the loader and lift arms both drop down? I had to pull out one of the keeps in my curl cylinder and assumed it would leak. It doesn't leak but the entire unit tends to drop over 1-2 days without any load and I thought maybe it was that cylinder causing it until the lift arms dropped also. No oil leak anywhere visible.

 

[J_J]

I would suggest that anyone that has concerns about their loader leaking, to unhook the hoses, and take the valve to a hydraulic shop that has a test bench. They can tell you if it is working or leaking, or whatever. You can almost bet that they will leak some. There may be some valves that have o-rings, and can be repaired, but the majority don't, and are supposed to be a precision fit, however, after hours of use, the original tightness will fade to some leaking over time. Remember that 10 or 25 micron filter, the particles smaller that the filter, will be circulating through you system, and causing wear. When they broke my pump down, I could see the wear marks. I know the valves in my Case skidsteer has o-rings. and can be replaced. Most of you know there are ways around the leaking down, and that is the pilot operated check valve.

Sure the dealer will replace parts under warranty if you can convince him of a problem, and if you holler loud enough, just don't expect to much, and he will replace it out of warranty as many times as you want. There really is no cure for the problem. Wayne says to holler at the manufacture, and yes they might do something, down the road. Most will say that is just the way it is.

Wayne, you can holler at those tractor dealers all you want, they are going to tell you the same story.

I think everyone is in agreement about whether the loader arms should leak down, and the answer is no, but, you know about it, and have seen it, and heard the complaints. I know it is going to happen on Power-Trac. and I know about how much it will leak down.