hyd control valve on 3 pt

[clemsonfor]

There is a spring and a ball bearing and then a shaft inside behind that big nut. The spring is not powerful and as long as your aware that it will come out when that last thread on the nut comes off you can easily hold it without any real effort and then just ease it apart watching how the pieces come out. I had a part fall out of mine when I took it apart cause I was in a hurry and could not figure what was wrong, I think I had the shaft thing or something in backwards. I pulled it apart several times thinking the oring was cut and I kept swapping them and looking, the diagram was not clear enough for me, finially I figured it out and swapped it around and got it back working right. Yes I did drop a piece, but I didn't know what was in there and I was rushing taking it apart, but each subsequent time when I pulled it apart there was not problem or remotely close to loosening a piece cause I was ready for it.

 

[kenmac]

They guy I talked to at fredricks said they sell a good many of these valves. So , I guess they go bad often.
I had no idea they had them made. I thought they were original yanmar stock

Winston, I will see if I can check this relief. It appears to be located under the big knob. I don't really know what I would / should be looking for in the relief to determine if something is wrong there ,or not

 

[clemsonfor]

Like I said mine leaks down a little when the tractor is off, but not near bad enough for me to want to spend $250 on it!!

 

[winston1]

Relief valve could have trash in it or a broken spring. Probably not, just thinking how fast you are leaking down sounds a little unusual for a control valve to leak that bad. Also, costs nothing to check.

Another edit. Going back to your first post stating high rpms to have loader function sure sounds like pump is going bad or suction stopped up. Your 3 point relief valve is down stream from your loader. But then again, the 3 point should not leak down that fast. Did this all happen pretty suddenly or over a long period of time?

 

[careyo63]

A pump works or it doesn't. Along with a spring breaking "So rare it Don't happen" and For another edit I brought up that the Suction "Pickup Screen was Dirty". On #2 post. It is almost more than apparent this is a Winston and Kenmac Thread. And one of you doesn't even own a Yanmar that he apparently couldn't keep up With LMMFAO........

 

[winston1]

Careyo63, I meant no offense by stating what you had already stated. My only intention here is to offer suggestions as they come to me. No idea what LMMFAO means. This is post #26, Kenmac leads with 10, his thread so sounds good to me. You come in second with 7 posts. I have 5 posts counting this one. Clemsonfor has 4 posts. Guess I need to post faster to catch up.

 

[kenmac]

winston, My system doesn't have the B like in the link you posted. I assume the B is where you are indicating the relief is. There is nothing under the big shut off screw.
My filter screen is clean. Since I've had this tractor, I changed the hyd oil, Last yr I changed over to Transmission fluid.
I shut the big knob off and the 3 pt holds.

At idle with big knob all the way out. the 3pt will drop. It will raise back up at about 1500 RPM

I think I solved the slow loader issue. When The tractor is first started in the AM. loader speed is great. It seems like I lose some loader speed after using the tractor for several hrs straight. I think the oil is getting hot and thinning out causing me to have to run higher RPM to get the same flow. I think I'm going to experiment with thickening the HYD fluid some (maybe add some STP) and see if that helps with the thinning of the HYD oil when it gets hot.

Clem, I intend on keeping the tractor even though I'm looking for a larger (50-55 HP) tractor . So, I may as well have it working right. I think they have those valves made in china. Probably why they go bad so often. LOL

Carey063, I have no idea what you mean by a kenmac/ winston thread. I have read and appreciate all the comments. I didn't comment about the dirty suction ,because I know it's not dirty.

 

[careyo63]

How do " You Know it's Not Dirty". What you are saying is your pretty sure you think it's not dirty. You haven't checked it so your Guessing it's not dirty or clogged.

 

[kenmac]

How do " You Know it's Not Dirty". What you are saying is your pretty sure you think it's not dirty. You haven't checked it so your Guessing it's not dirty or clogged.

I'm so positive it isn't that I would be willing to bet it's not.

For enough trash to be in the hyd system to stop it up, It would have to get in there from some outside source. It isn't just going to clog up from the transmission fluid and alone.

A few metal shavings on the filter ? Maybe, but fluid was replaced and filter cleaned within the last couple of yrs
I have replaced transmission filters on vehicles with over 100 K . Those filters were almost like new

 

[careyo63]

Your Guessing!! Water,Rubber,Metal,Gasket material, All of these things could do it. What are you out to check it. To much for you to handle doing it? Then you can rule it out. If it's all good pour it back in.

 

[kenmac]

I have no doubt it's clean. You are guessing it's dirty

If I wanted JD303 in it, I would have put JD303 back in when I changes it last yr.

 

[careyo63]

Well if you want it to work correctly you might want to use JD303 or equivalent........ That just maybe the problem. Something Changed and that is no doubt it was that.....

 

[Neat 1500]

I'm not joining the bandwagon but..... I think it could also be something to do with the trans fluid in it. The pump may be a bit lazy and a few other bit worn which is amplifying your problem. As it warms it does turn to water, I notice this with my YM14 trans. Great when it's cold but a bit ordinary when hot.

 

[winston1]

Kenmac, the relief valve is shown in the very bottom parts drawing in that link from post #20 with reference numbers 27 through 38.

 

[rScotty]

Kenmac, the relief valve is shown in the very bottom parts drawing in that link from post #20 with reference numbers 27 through 38.

Winston, I just went to that link and read through the article above that illustration. There is at least one striking inaccuracies in the text of the article which could lead a person down the wrong path entirely, and that makes me wonder just how universal that illustration is. Do we know what model Yanmar is being referenced in post #20?

Looking back on the original post #1 on this thread....if it were my tractor doing that I would go back and get some more information and do some diagnostics. Kenmac says the loader is slow. Well, that could have several causes. Along that line, does anyone know how similar - or not - the gray market YM3110 is to the US YM336? I ask that because I am more familiar with the YM336. It's has a type of standard factory power steering and a proportioning valve which made its hydraulics work a bit different from the under 30 hp YM series.
rScotty

 

[kenmac]

I'm not joining the bandwagon but..... I think it could also be something to do with the trans fluid in it. The pump may be a bit lazy and a few other bit worn which is amplifying your problem. As it warms it does turn to water, I notice this with my YM14 trans. Great when it's cold but a bit ordinary when hot.

Yes, I believe as it gets hot, The fluid thins out too much causing everything to slow down.
At first, I thought it may be something to do with the 3pt control valve. After using the tractor first thing in the mornings, I really noticed how well the loader works until it gets hot.

It did the same thing with the JD303, which is why I switched to transmission fluid.
I believe tractor Ernie used transmission fluid in all his yanmars and never reported any problems.

 

[winston1]

rScotty, I don't know what model the illustrated tractor is. Yes, Kenmac does have power steering. I too, as Carey pointed out, had a 2002D with the factory power steering and factory diverter (proportioning valve). Never experienced the problems Kenmac is having.

 

[kenmac]

Winston, I just went to that link and read through the article above that illustration. There is at least one striking inaccuracies in the text of the article which could lead a person down the wrong path entirely, and that makes me wonder just how universal that illustration is. Do we know what model Yanmar is being referenced in post #20?

Looking back on the original post #1 on this thread....if it were my tractor doing that I would go back and get some more information and do some diagnostics. Kenmac says the loader is slow. Well, that could have several causes. Along that line, does anyone know how similar - or not - the gray market YM3110 is to the US YM336? I ask that because I am more familiar with the YM336. It's has a type of standard factory power steering and a proportioning valve which made its hydraulics work a bit different from the under 30 hp YM series.
rScotty

The 3110 also has this valve. The manual states that ps has priority . After checking , I think my loader problem is related to the fluid getting hot and thinning out causing the pump not to flow as well

I have transmission fluid in it now, but it did the same thing with JD303 fluid.

I did add some STP to the fluid to see if it would help the fluid stay thicker when hot, and yesterday when I used the tractor all day, It seemed to really help !

 

[winston1]

I'm sure thinning fluid could cause some slower response but I think you have other issues. When I used my 2002D all day I could not tell any difference in the speed and it did get hot. Still thinking you have something leaking by or a badly worn pump.

 

[rScotty]

The 3110 also has this valve. The manual states that ps has priority . After checking , I think my loader problem is related to the fluid getting hot and thinning out causing the pump not to flow as well

I have transmission fluid in it now, but it did the same thing with JD303 fluid.

I did add some STP to the fluid to see if it would help the fluid stay thicker when hot, and yesterday when I used the tractor all day, It seemed to really help !

Maybe...... Are you thinking that you may have two entirely separate problems? Even if the pump itself is worn, I don't see how the 3 point dropping would be connected to the pump. That's more likely to be a leaky valve somewhere in the system. On the other hand, a leaky valve would certainly make the pump appear weak.

It sounds to me like you are going to replace that relief valve in the 3pt anyway. I agree that would be a good place to start, and might even be the whole problem. Based on what's been written, I'd do that in any case.

There's a lot of trans/hydraulic fluids on the market. Frankly I've not found much difference in any of the name brand trans/hydraulic fluids. That may be because our little tractors just don't really stress a modern trans/hydraulic oil. JD makes a low vis 303, but I've not heard of a high vis 303. A pump would have to be really, really WORN before you will see a difference based on viscosity. And if it was that worn I'd think that you would also see quite a difference in loader speed depending on how much load you are lifting. Do you see that? Not just empty vs clear full, but depending on how full.

Just thinking out loud now.....Lots of oil companies market a JD 303 "lookalike"oil. No idea if they really are the same or not, and no idea how to tell.

Most Yamars had multiple hydraulic filters. Typical setup was for one to be a spin-on high pressure filter, and the other was a hand-cleanable tubular stainless screen down lower. I change the spin-on every 5 years or so when I remember to, but have never seen that make a difference. I have seen the hand-cleanable screen filter clogged up so much with some sort of dirt and oily film that it restricted flow. But that was in Yanmars with a power shift tranny and there the main symptom was slow engagement when power shifting gears.
luck,
rScotty