Yanmar 336D FEL only works when 3 point is raised to max and straining the engine!?

[bulldogmack407]

Hello, i tried solving this problem on other forums but had no luck. I bought a Yanmar 336D for $1000 recently. The tractor is in decent shape and runs/operates great. However the tractors FEL will not operate unless you raise the 3 point hitch beyond MAX to the point where you can hear the engine bogging down a little. You can also see one of the lines going to the spool valve tense up. If you use the loader the engine tone returns to normal and the line is not tense until you stop using the loader or lower the 3 point. I replaced the spool valve that was on it when i got it however it did the exact same thing with the old one. The reason i replaced the old one was because it was cracked. There are 3 lines hooked to it besides the 4 ones for the loader cylinders. One of the lines just goes into the reservoir (trans housing) and the other 2 go to a block under the seat. I have spoken to several people and some have told me there should only be 2 lines not 3. I also have a power beyond valve on one of the lines. The only reason i installed the power beyond is because i was told with 3 lines i need it and with 2 you dont. I have included photos of the set up. On all the other forums i got alot of people telling me to cut the steel lines from the pump and plumb things in and people speculating. This machine has the factory loader on it so i know it will work somehow without re engineering the hydraulic system so please dont give me those answers. If you have one of these tractors could you please send me photos or show me where the lines go and tell me weather or not i need the power beyond valve. I love this tractor even with the issues it has at the moment and really want it working without issues.

Thanks

 

[J_J]

Your tractor is open center, so all valves go in series.

When adding valves, you need a valve with PB in order to pass fluid downstream.

All tank lines go to tank via a return line.

Your loader probably gets the fluid first, so it must have the PB adapter installed.

All other valves will be in series and need a PB port with adapter.

 

[bulldogmack407]

Your tractor is open center, so all valves go in series.

When adding valves, you need a valve with PB in order to pass fluid downstream.

All tank lines go to tank via a return line.

Your loader probably gets the fluid first, so it must have the PB adapter installed.

All other valves will be in series and need a PB port with adapter.

So if the loader is first then i was right to install a PB, the tractor always had this loader on it so the issue is not a loader being added or anything. That being said what could the problem be?

 

[Leejohn]

Why are there two hoses from loader valve going to same place?

 

[bulldogmack407]

No idea, this is the way it was set up when i got it. I am lost when it comes to where everything SHOULD go. I have emailed several people asking for photos of their tractor

 

[Leejohn]

Go to Prince Manufacturing Corporation Home Page and look at some of the drawings. See if you can find something like you have. You don't care a hole lot about what kind of valve you open, just look over the plumbing. I think it might be plumbed wrong.

 

[bulldogmack407]

Go to Prince Manufacturing Corporation Home Page and look at some of the drawings. See if you can find something like you have. You don't care a hole lot about what kind of valve you open, just look over the plumbing. I think it might be plumbed wrong.

I received a diagram with the loader valve from them. I hooked up the valve how the diagram showed and it was the same way the valve was installed before. A week ago i actually switched the two other lines (not the return-tank line) and it functions exactly the same.

 

[Leejohn]

What is it that the hoses are hooked to in the 1st picture.

 

[bulldogmack407]

Its some sort of hydraulic block bolted to the 3 point housing, there is a lever on top of it to increase or decrease the hydraulic speed.

 

[Leejohn]

Well it seems like your loader is working off of back pessure from the 3 pt and that is why it is only working with the 3pt lever all the way up. Your pic #2 is small and can't tell where the lines go. The 2 hoses that are coming back to loader valve in picture #1 just where do they hook up at the valve?

 

[bulldogmack407]

Well it seems like your loader is working off of back pessure from the 3 pt and that is why it is only working with the 3pt lever all the way up. Your pic #2 is small and can't tell where the lines go. The 2 hoses that are coming back to loader valve in picture #1 just where do they hook up at the valve?

Just took this photo and labeled the lines

 

[Leejohn]

If the hose on the right going into the valve is the pressure line then it's right. There should not be any pressure at the PB adapter hose. I would unhook the right and left side put ends in a pal, then start or just turn over engine. The hose that has oil coming out goes on the right or in port and other goes to the PB adapter. There is a good chance the plate that you are hooking the hoses in the back is the wrong one or maybe a bad o ring and letting the oil pass over to the other hoses, putting pressure on both lines. I would do the hose in a pal thing, then pull the plate and look at it. Other then that it looks right to me.

 

[kenmac]

Post this in the yanmar section. There are members that have a 336 with a loader. They will be glad to take picks and tell you how their loader is connected. I believe (not sure) that there is already hp at the block you are referring to so, you may not need the pb port. I have the sister tractor to yours ,but mine is plumbed differently

 

[bulldogmack407]

If the hose on the right going into the valve is the pressure line then it's right. There should not be any pressure at the PB adapter hose. I would unhook the right and left side put ends in a pal, then start or just turn over engine. The hose that has oil coming out goes on the right or in port and other goes to the PB adapter. There is a good chance the plate that you are hooking the hoses in the back is the wrong one or maybe a bad o ring and letting the oil pass over to the other hoses, putting pressure on both lines. I would do the hose in a pal thing, then pull the plate and look at it. Other then that it looks right to me.

I just recently, about a week ago switched those 2 lines and everything functions exactly the same.

 

[Leejohn]

Switching hoses might not do it if both have pressure. It is a good ideal to try the yanmar site like kenmac said to see if someone well post some pictures for you. Sorry I couldn't be more help, but don't over look that plate the hoses hook in to.

 

[kenmac]

You probably already know this ,but it would seem you aren't getting any pressure from that block to supply pressure to the FEL valve. The problem may be in that block that supplies pressure to the loader valve

 

[bulldogmack407]

Switching hoses might not do it if both have pressure. It is a good ideal to try the yanmar site like kenmac said to see if someone well post some pictures for you. Sorry I couldn't be more help, but don't over look that plate the hoses hook in to.

Your help is most appreciated, i will try a yanmar site. I cant wait till this thing is finally fixed!

 

[bulldogmack407]

You probably already know this ,but it would seem you aren't getting any pressure from that block to supply pressure to the FEL valve. The problem may be in that block that supplies pressure to the loader valve

Kenmac, your 3110D looks almost identical to my 336D, do you have that block on yours for your FEL?

 

[kenmac]

You don't have to find a Yanmar site. Just scroll down the page on this site for the yanmar section. No. That's why I said in my post, that my loader is plumbed differently than the 336. Though it is basically the same tractor.I have a Koyker aftermarket loader My 3110 is the GREY version of your 336. Looking at the pics. the line marked line 2 from the block should feed hp to the FEL valve inlet. Is this correct? Just to let you know , My steel HP (small line) from the pump was cut. then routed to the inlet loader valve PB is then run to the 3 point. and outlet to the tank. Most if not all GREY'S are plumbed this way. Most (GREY;S) don't have a tank return

 

[bulldogmack407]

You don't have to find a Yanmar site. Just scroll down the page on this site for the yanmar section. No. That's why I said in my post, that my loader is plumbed differently than the 336. Though it is basically the same tractor.I have a Koyker aftermarket loader My 3110 is the GREY version of your 336

Is it possible for me to plumb mine the same as yours or will i have to cut lines to do it? I just want this **** loader working as it should without cutting the steel lines like many suggested to me.