Unusual Hydraulic Issue

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chrisg727
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Unusual Hydraulic Issue

Postby chrisg727 » Wed May 30, 2018 2:20 pm

I have an unusual issue with the hydraulics on my Yanmar 1810D. The 3 pt lift will not raise. I have a loader on the tractor and it works but it seems "weak" in that I can't seem to lift more than 100 lbs or so. I changed the fluid and cleaned the screen hoping that would solve the problem. No luck. Could it be a pump issue? Not sure how to check hydraulic pressure or what is normal for this tractor. Any advice would be appreciated. Thanks!

winston
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Re: Unusual Hydraulic Issue

Postby winston » Thu May 31, 2018 9:54 am

Your pressure should be around 2000psi at the relief valve. You will not see that pressure unless system is loaded enough to raise it. Definitely sounds like a pump problem. Do you think you could have done anything to dead head your pump? What happens when you raise or curl you loader until it reaches the end of the cylinder stroke? Do you hear a relief valve going off on the loader control valve or nothing at all. If nothing at all it would even point more to the pump or pump coupling being bad.

chrisg727
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Re: Unusual Hydraulic Issue

Postby chrisg727 » Sun Dec 02, 2018 10:09 pm

Finally got back to working on the tractor. I installed a new hydraulic pump. Still have an issue in that the 3 point lift arms won't raise. I noticed this time that if I raise the loader to full height and leave it there it ver slowly "bleeds down" or lowers. This would seem to indicate a leak in the system but I've been unable to locate any. The only place I haven't looked is the 3 point lift itself. Question: can the lift unit be opened up and, if so, might there be any components inside the housing that could have failed or are leaking? I'm a completely new to this so any insights would be appreciated. Thanks!

chrisg727
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Re: Unusual Hydraulic Issue

Postby chrisg727 » Sun Dec 02, 2018 10:28 pm

Wanted to add that the hydraulic fluid has been changed and the filter screen cleaned. The old fluid looked pretty good actually. Stop valve is fully Open. The lift arms were working but just quit operating. Thanks!

winston
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Re: Unusual Hydraulic Issue

Postby winston » Mon Dec 03, 2018 4:55 am

With the new pump will the loader still only lift a 100lbs or so?

chrisg727
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Re: Unusual Hydraulic Issue

Postby chrisg727 » Mon Dec 03, 2018 5:50 pm

I haven't had a chance to "stress test" the loader yet. Pretty cold up north here right now :shock:

One thing I did notice is that the new pump puts a more notable demand on the engine than the old one. I'm assuming that it's now "working harder" than the old one(?) so maybe can lift more weight.

Today I noticed a slight bit of leakage on the right hand (as you're sitting on the tractor) lift arm. Appears to be coming from the lift arm housing. Maybe the source of the "bleed down" leakage(?)

Thanks for your input!

winston
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Re: Unusual Hydraulic Issue

Postby winston » Mon Dec 03, 2018 6:16 pm

The pump should not put a load on the engine unless the loader or 3 point is activated. Maybe not what you are saying, sometimes typed words can be hard to interpret.

chrisg727
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Re: Unusual Hydraulic Issue

Postby chrisg727 » Tue Dec 04, 2018 6:39 pm

Yep, the written word isn't the perfect form of communication. :D I meant that the "loading" takes place when the FEL is operated.

I'm beginning to wonder if I might have a control valve issue as the small leak is coming from the side where the valve is located, i.e. the side where the handle to raise/lower the 3 point is. Not sure what might be involved in checking this out though.

winston
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Re: Unusual Hydraulic Issue

Postby winston » Wed Dec 05, 2018 6:07 am

chrisg727 wrote:Yep, the written word isn't the perfect form of communication. :D I meant that the "loading" takes place when the FEL is operated.

I'm beginning to wonder if I might have a control valve issue as the small leak is coming from the side where the valve is located, i.e. the side where the handle to raise/lower the 3 point is. Not sure what might be involved in checking this out though.


Could be the valve but I would want to confirm the loader is now fully functional before opening up the 3 point valve. Mind me asking where you reside?

chrisg727
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Re: Unusual Hydraulic Issue

Postby chrisg727 » Wed Dec 05, 2018 2:05 pm

Winston:

Thanks for the reply. I live in Sprague, Washington which is about 35 miles SW of Spokane. How about you? What part of East Texas do you reside.

I'll check the loader ASAP and see. I realize I neglected to add some pertinent information on this. I'm not 100% sure but I think the rear lift arms stopped working when I blew a seal on my FEL lifting hydraulic cylinder (there's only one on this set up, not real strong to begin with). I replaced it with a Magister unit of the same size and other than the bleed down issue, it seems to work OK now. I can see no leakage of any kind at the loader cylinders, lines, or control box. Everything is clean and dry.

As I indicated, I'm seeing some slight leakage (weeping) around the right rear lift arm where it comes out of the housing. Probably a seal that needs replacing. Just a guess though.

As far as the hydraulics are plumbed, the FEL comes off the pressure side of the pump. The return from the FEL then goes to the hard line that feeds the rear lift mechanism. I'm assuming that the pressure going back to the rear lift is good but don't know for certain. I've contemplated rigging up something to bypass the FEL and feed the rear lift directly. When I changed the pump I tried to reconnect the rear hard line to the pump output but evidently when the FEL was installed, the hard line was "reshaped" so that the FEL circuit could be installed. I tried to resend the line but couldn't get it to mate with the pump. I didn't try too hard though as I was concerned about breaking the hard line.

On my rear lift, the Raise/Lower lever enters the side case on the right. That looks OK. There is a rod that comes out of the same side, down lower, that is connected to the right arm (as sitting on the tractor). I think this is the control lever linkage rod. Everything seems to be connected OK. However, there is something odd to me. On the shaft that comes out of the housing, the one the control lever linkage is connected to, there is an "arm" that looks like something can be connected to it, but nothing is. If I raise the rear lift arms manually, it moves with them. Don't know what this is supposed to be for as I can't see that there's anything nearby that might attach to it. My service manual doesn't show this "arm" in the picture (although the manual is for a YM220/226 which is as close as I can get to the 1810).

Not sure if any of this sheds some light on the potential source of my issue. As I think I mentioned previously, I'm new to this.

Thanks again for your help. Hope thinks are a bit warmer down there in E. Texas :)

Chris

winston
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Re: Unusual Hydraulic Issue

Postby winston » Wed Dec 05, 2018 2:39 pm

Was hoping you might live closer but didn't work. I live in the Longview/Tyler area of Northeast Texas. I am thinking your 1810 probably had provision for a cable controlled draft control for a tiller.
100_5034.JPG
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Wouldn't doubt yours is very similar to my old 2002D shown here.

Yours is plumbed as the majority of the older Yanmars with added loaders. I later plumbed mine with power beyond but no reason yours shouldn't work the way it is plumbed.

There is no pressure where the rock shaft comes out of the lift housing or where your lift arm is attached. If the leak is not bad I wouldn't be concerned with it. Should have no effect on your problem.

"If" your loader picks up a load with ease then your control valve would seem to be the next place to look.

I read back over the thread and might have missed it but your surely your stop valve is not closed??

chrisg727
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Re: Unusual Hydraulic Issue

Postby chrisg727 » Thu Dec 06, 2018 1:25 pm

Thanks for your reply again! Your 2002 does indeed resemble my 1810. Thanks for clarifying the purpose of the "arm."

Yes, the stop valve is fully open so I'm going to check on the control valve as it does seem to be the next logical step.

Thanks for the insight on the "weeping" around the rock shaft (didn't know that's what it was called). I'm glad to know that I won't have to tear that apart too.

Have a great day!
Chris

chrisg727
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Re: Unusual Hydraulic Issue

Postby chrisg727 » Tue Jan 14, 2020 4:14 pm

So I finally got back to working on my 3 point issue. Here's where I'm at now:

I removed the FEL (I found a used Koyker 80 that I'm going to replace the old one with once I get this issue resolved).

The high pressure output from the (new) hydraulic pumps now goes straight back to the hydraulic lift via the smaller diameter hard line. Low pressure still comes back to the pump via the larger diameter hard line.

After removing the FEL, the 3 point lift is still not working.

Hydraulic fluid was changed and filter cleaned out last year. I've now drained the hydraulic fluid again and will re-check the filter screen.

I removed the seat and right wheel/fender (for ease of access) and opened the side casing containing the control valve. I've inspected the linkage that depresses/releases the "plunger" on the control valve. It looks to be operating fine.

So now I have the control valve out. I can press the "plunger" in manually and it pops right back out. Spring pressure is good and it's not hanging up. The two O rings look to be OK.

My question is "what now?" I haven't disassembled the valve yet. Is there a way to check the valve without tearing it apart? I have a maintenance manual I purchased from Hoye but the the control valve in the manual is a bit different than mine. I am including two pics of the control valve with this post.

Any additional help would be very much appreciated! Thanks!
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winston
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Re: Unusual Hydraulic Issue

Postby winston » Tue Jan 14, 2020 6:48 pm

I think this is the valve you have.
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Several O-rings in there and possibility of trash. You have pretty much covered other bases. I think being careful and with this drawing to help you a tear down may be in order. Of course it is your call but good luck in whatever you choose.

chrisg727
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Re: Unusual Hydraulic Issue

Postby chrisg727 » Wed Jan 15, 2020 12:13 pm

Winston,

Sure does look like my valve! Going to go ahead and tackle opening it up and see if I can find anything wrong inside.

You continue to be a great resource of information. Thanks again!

Chris


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