YM2000

Post your questions or problems you are haviing with your Yanmar tractor here.

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woodtore
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YM2000

Postby woodtore » Wed Jun 10, 2020 7:02 pm

Hello all,

I had 3pt lift drop on my YM2000. I had drop when the hand valve was closed so I replaced the three point piston oring and backup seal as well as most of the other orings in that area. That fixed by drop when the hand valve was closed but I still had drop when I throttled back so I replaced the control valve HHV-451. This fixed the problem for about an hour of use so here are my current observations.

HHV-451 was a pain to get bolted up because the mounting holes were very inaccurately placed.
When things went south I only had up hydraulic power when throttled up. When idled back I had 3pt drop.
At this time I had no down control. Drop the level and hydraulic control piston did not follow the lever.
After a few minutes I had no hydraulic power up independent of RPMs.
No loader hydraulic power.
The hydraulic control valve piston appears to be stuck forward( the piston is not riding against the lever).
I pulled the hydraulic oil strainer. It had some build up but I wouldn't call it clogged.
Hydraulic oil level was acceptable.

On the old hydraulic control valve there is a spring that keeps the hydraulic control piston toward the rear of the tractor but when I received the valve in the mail today I noticed that piston was not in the rearward most position. When I started the tractor the piston moved rearward after it received power. Does the new valve not have a spring? Is their a chance I have a lemon for a valve(the hole location real has me questioning the quality of the valve)? But that would not explain the lack of hydraulic power on the loader, right?

What in the world do I have going on here?

Thanks in advance.

Aaron
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Joined: Thu Jul 26, 2007 12:39 pm
Location: Iowa Park, TX

Re: YM2000

Postby Aaron » Thu Jun 11, 2020 12:15 pm

Does the new valve not have a spring?

I think they all need to have the same internals.
https://www.hoyetractor.com/CTGY/YM15003PTVALVE.htm

Is their a chance I have a lemon for a valve(the hole location real has me questioning the quality of the valve)?

Possible. They are not my favorite part that we sell- for sure. That being said, while there have been a few warranty claims that may or may not have been the fault of the valve (many of the problems ended up being caused by something else), we have not statistically had many problems with them.

The bad news is that we sold our last one and do not have any ETA when we will be getting more so if yours is bad my only option is a refund at this point.

But that would not explain the lack of hydraulic power on the loader, right?


Correct.

winston
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Re: YM2000

Postby winston » Fri Jun 12, 2020 4:19 am

I certainly don't have a good answer but "IF" the control valve is putting back pressure on your loader valve and not letting the fluid pass through this could cause no loader power. Is you engine loading up when this is happening? I would also wonder if your 3 point relief valve is leaking badly causing your drop while running.

woodtore
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Re: YM2000

Postby woodtore » Fri Jun 12, 2020 7:55 am

Thank you Aaron and Winston for your responses. I am going to be away for the weekend. When I return I will take a look at the relief valve.

Aaron, would you mind if I popped open the control valve to see what is going on in there?

I was reading another post regarding the different configurations for loader control(6 hose and 7 hose). Could someone help me understand the differences? I have 6 hose. So I believe that I don't have a relief valve in my loader valve right. When my loader lever is in the neutral position it is just passing power on to the three point control valve? When I engage one or more of the cylinders on the loader, power is filling that half or set of halves of cylinders which in turn passes the oil from the other half or halves of the cylinders engaged on to the three point control where it must overcome the relief valve?

woodtore
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Re: YM2000

Postby woodtore » Fri Jun 12, 2020 7:57 am

Winston, I forgot to answer your question. No, the engine is not loading up in any set of conditions.

Torey

winston
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Re: YM2000

Postby winston » Fri Jun 12, 2020 10:11 am

Six hoses means no power beyond. Probably most of these older Yanmars are plumbed that way. Yes, your control valve will have a relief valve in it.
The outlet on your loader valve going to the 3 point should be labled outlet. If the valve is power beyond capable it might have an opening that is plugged and might be labeled pb or something indicating power beyond.

You are right about how the loader valve operates but the flow does not have to overcome a relief valve at the 3 point. If 3 point is not in immediate use the flow from the loader valve just passes through the 3 point valve into the transmission sump. Now if your 3 point valve is not functioning correctly and letting the flow go through then that flow could be meeting relief valve pressure. If that were the case your loader would likely sturggle. Remember this is an old mans ramblings, no facts here.

woodtore
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Joined: Wed Jun 10, 2020 6:41 pm

Re: YM2000

Postby woodtore » Sun Jun 28, 2020 5:17 pm

Well, I finally had time to look at the tractor. I opened the control valve and the piston was stuck in one location. That is why the piston was not following the control lever. I pulled the piston out, cleaned it up and put it back in. It appears to be unstuck at this point but we will see if it has a hang up spot after a little use. On the front side of the control valve piston there is a spring loaded stud that hangs often when I cycle it.... Not sure what to make of that.

But anyway I am now waiting on the screen kit because I ripped the screen when pulling it out.

Torey


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