Loader Hydraulic issues, No back Pressure after the Loader controls?

[scooter133]

Yanmar YM2002D, I've been trying to troubleshoot a Hydraulic issue. The 3Pt and Bucket don’t work.

I've replaced the Filter and Oil. I've cleaned the Screen, I've made sure the lines are clear. I can Pull oil from the screen filter to the oil filter. I can shoot oil out from the Exit port on the Loader controls (Line back into the Hydraulic cylinder case)

So the oil is clean, filters are clean, seems to be getting from the tank/Transmission to the bucket control, but there is no pressure. The Quick Connect can be taken apart when the tractor is running, so I know there is no pressure there.

I dont know much on the Hydraulic cylinder case/Relief Valve box, what it does and what issues it could have. If everything upstream of this is Okay, what do I do with the Hydraulic cylinder case to make sure it's doing what it needs to do?

I’m thinking it might be something in the Hydraulic cylinder case/Relief Valve box that is not able to keep the Pressure.

Thank you,

 

[winston1]

I am old and slow, not understanding just what your problem is. Are you saying you have a loader and it works but the 3 point does not? Your showing you own a John Deere D155, is that what we are talking about? Your picture looks like controls on a Yanmar. Please tell us the model number. Wanting to help, just not informative enough for me to understand.

 

[scooter133]

I am old and slow, not understanding just what your problem is. Are you saying you have a loader and it works but the 3 point does not? Your showing you own a John Deere D155, is that what we are talking about? Your picture looks like controls on a Yanmar. Please tell us the model number. Wanting to help, just not informative enough for me to understand.

Thank you. I updated the Question. It’s a YM2002D. No Hydraulic control. Only thing not taken apart is the Hydraulic control case/relieve valve box. Seems like its not keeping the pressure from the Pump.

 

[winston1]

Not sure what quick connect you are talking apart. Possible pictures of disconnects? If it was a disconnect that stopped flow you may have sheared your pump key. Your hydraulic system has flow at all times. If you stop that flow your pump will disintegrate or shear the key of coupling that drives the pump. I know you stated you have flow but do you have flow when under pressure? "If" the key is sheared the friction on pump shaft might be enough to flow fluid but not enough to pressure the system. I have no way of knowing this could be your problem but just something to ponder on. Do you have any reason to believe you might have stopped flow at one time or another?

 

[scooter133]

Not sure what quick connect you are talking apart. Possible pictures of disconnects? If it was a disconnect that stopped flow you may have sheared your pump key. Your hydraulic system has flow at all times. If you stop that flow your pump will disintegrate or shear the key of coupling that drives the pump. I know you stated you have flow but do you have flow when under pressure? "If" the key is sheared the friction on pump shaft might be enough to flow fluid but not enough to pressure the system. I have no way of knowing this could be your problem but just something to ponder on. Do you have any reason to believe you might have stopped flow at one time or another?

He Quick Connect was installed after the Bucket controls and before the return to the Hydraulic Case. It allowed the connection to add a Top/Side link control for the 3 Point. Though I’ve removed that and have the Bucket controls going back into the Hydraulic Case directly vs the 3Pt Control. I’ve been running without the 3Pt control for some time, so I know that is not the issue.

Have I stopped flow. Prior to last night, no. There has always been flow through the pump to either an open end hose, or through the controls or back into the Hydraulic Case.

Last night instead of disconnecting the hose from the exit of the bucket control, I just disconnected the Quick Connect. I didnt know the Male end of the Quick Connect would hold pressure if not connected. Trying to start the tractor with it disconnected, it would not start. The Hoses flexed, but engine didnt start. Reconnected, engine fired up.

It does seem like a pressure issue. Too much Air, Not able to Keep up with the pressure or the pressure relief system is not able to hold the pressure needed.

Starting the tractor after it sits for 10-20 Mins, I can work the bucket for less than a Minute. When I say work, that just means I can get some jitter movement and may be able to lift the bucket 2 feet in a Minute of futzing with the bucket control.

3Pt Will maybe lift at the start. Once you lower it, it’s not coming back up until the next rest cycle. Using the 3pt lessens the time that the bucket ‘works’

When there is pressure in the line the Qucick Connect pull back ring wont spin. No Pressure. You can spin and take it apart. So I guess I did that once while it was running. Though that was before the same issues I’m having.

To test if I sheared it off. I need to remove the pump from the engine, or the front of the pump off? I’m not sure if the key is on the fluid side of the pump(Pushing fluid) or the Engine side (driving the pump)

Attached is the Quick Connect and side/top view of the pump.

 

[winston1]

The tractor not starting with the quick connect disconnected indicates your pump is ok because it was pressuring. Good thing it didn't start or you would be replacing the key and or the pump.

I cannot tell just how you are plumbed but I would suggest you do it this way. Yanmar Tractor Loader Install Instructions
I ran my old 2002D several years plumbed just like that and later changed it to power beyond. Are you confident your screw on filter is the correct micron? If not, it will choke the fluid flow. I used a wix 51203 which is a 30 micron.

 

[scooter133]

The tractor not starting with the quick connect disconnected indicates your pump is ok because it was pressuring. Good thing it didn't start or you would be replacing the key and or the pump.

I cannot tell just how you are plumbed but I would suggest you do it this way. Yanmar Tractor Loader Install Instructions
I ran my old 2002D several years plumbed just like that and later changed it to power beyond. Are you confident your screw on filter is the correct micron? If not, it will choke the fluid flow. I used a wix 51203 which is a 30 micron.

The Filter Screen (not screw?) is the original that has been working for years and years.
I dont think the filter screen, or the intake are the issue.

I’ll Check out the Link…

Thank you!

 

[winston1]

The Filter Screen (not screw?) is the original that has been working for years and years.
I dont think the filter screen, or the intake are the issue.

I’ll Check out the Link…

Thank you!

Not saying the screw on filter or the suction strainer is the problem. Just pointing out possibilities causing your problems.

 

[kenmac]

If that quick connect coupler line is connect straight to the pump, and you disconnected that, and started it, You deadheaded the pump

 

[ptsg]

If that quick connect coupler line is connect straight to the pump, and you disconnected that, and started it, You deadheaded the pump

And without any relief valve in between, it's a recipe for disaster indeed.