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.

 

[scooter133]

Okay, here is more info.

Still have jerky minimal control for a few moments after start up.
What I've taken apart/seen.
Intake Screen - cleaned
Pump seems to be able to build pressure, cant seem to sustain it.

Took apart the relief valve to the parts shown- Spring and valve pin. Valve pin had slightly burred edge. used ceramic edge to smooth.

Replaced all. Can get oil to flow from top of pressure relieve. Tighten back down and bucket performs the same jerky movements.

That one with the O-Ring seems to be where I'm headed next. Though I'm not sure?

 

[winston1]

You have two control levers for the 3 point lift. One that raises and lowers, the other is for draft control. Have you tried moving the draft control lever to different positions to see if it effects anything? I remember my old 2002d was effected in some way, just can't remember just how.

 

[careyo63]

Look inside the lines. Had the same thing pretty much happened on the Fords Wagner. NTM. so I was doing Maint. and changed the Hyd. fluid cleaned the filter etc.. Started it up and it did the same thing. Pulled it back down and checked the screen which is a Basket just before the pump which is driven off the Eng. Crank shaft so real easy to access. It was clean still and full of Fluid! thought that was odd that was Happening. Luck have it I happen to look inside the hyd. line itself and Wahla!! The hose swelled up inside at a bend and had the line almost pinched off. I Replaced the line actually shortened that section to prevent it happening again and has been working ASIS every since. You can see the small section just before the Strainer basket in the Pick. Barely see it on the L.side. Only a couple inches to were it use to be at least 6 inches easy. Replaced and cleaned both pump lines and it's been trouble free!

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[scooter133]

I was able to remove the bucket controls from the line. So it’s just the screen, filter, Pump QuickConnect, then back into Hydraulic control valve.

3Pt was still wacky.

Pressure gauge shows not even 500PSI when put inline.
Pressure gauge pegged passed 3000 when I cranked the engine (no gas).

Took apart the Hydraulic controller. The O-Ring on the cylinder in there has some rough spots. Looking for the replacement O-Ring.

Took quite a bit to get the Cylinder out of there. Most of the videos I watched it just slides out. I need to Add compressed Air to push it out. I was stuck or so it seemed?

 

[scooter133]

Look inside the lines. Had the same thing pretty much happened on the Fords Wagner. NTM. so I was doing Maint. and changed the Hyd. fluid cleaned the filter etc.. Started it up and it did the same thing. Pulled it back down and checked the screen which is a Basket just before the pump which is driven off the Eng. Crank shaft so real easy to access. It was clean still and full of Fluid! thought that was odd that was Happening. Luck have it I happen to look inside the hyd. line itself and Wahla!! The hose swelled up inside at a bend and had the line almost pinched off. I Replaced the line actually shortened that section to prevent it happening again and has been working ASIS every since. You can see the small section just before the Strainer basket in the Pick. Barely see it on the L.side. Only a couple inches to were it use to be at least 6 inches easy. Replaced and cleaned both pump lines and it's been trouble free!

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  pump.JPG

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I’ll Check out the lines out, though I am getting flow to the Hydraulic valve Controller, It gushed out of the input there when I loosened the connectors.

 

[careyo63]

I’ll Check out the lines out, though I am getting flow to the Hydraulic valve Controller, It gushed out of the input there when I loosened the connectors.

Pumps work or they don't pretty much. The pump is working so you have a problem with the amount of Hyd. fluid being pumped. Just because you have pressure the problem is not enough fluid. Suction side to the Hyd. pump is my guess. Why I'm saying this is I worked for a swimming pool store and That is very common for that to happen. I did the repair work also! Commercial and Residential pools!! I knew to pull mine back down and start to look for a problem, The Bio lab plant in Ga. on fire. I know it well. Local....Chlorine!

 

[ponytug]

I was able to remove the bucket controls from the line. So it’s just the screen, filter, Pump QuickConnect, then back into Hydraulic control valve.

3Pt was still wacky.

Pressure gauge shows not even 500PSI when put inline.
Pressure gauge pegged passed 3000 when I cranked the engine (no gas).

Took apart the Hydraulic controller. The O-Ring on the cylinder in there has some rough spots. Looking for the replacement O-Ring.

Took quite a bit to get the Cylinder out of there. Most of the videos I watched it just slides out. I need to Add compressed Air to push it out. I was stuck or so it seemed?

Yes, that o-ring looks bad to me, both in this photo and the slightly out of focus one before. However, I would look inside to see if there is rust or scars or scratches that could have caused the nicks/wear in the o-ring. It would be great to find the cause of the wear on the o-ring. If you don't, I think that you run the risk of this repeating itself.

I would not rule out the thought that part of your issues is water in the hydraulic oil, causing a clogged suction screen.

The nicked o-ring might explain the "glitches", but it probably doesn't entirely explain the low pressure.

Good luck!

All the best,

Peter

 

[winston1]

Not understanding the 3000psi when cranking the engine. You are not going to have much pressure unless your lift is requiring it. (big load). On the 20002 you can slowly close down on the stop valve and watch your pressure gauge. The 2002d has a relief valve built in the 3 point control and it will or should relieve a little over 2200psi. I wouldn't necessarily recommending making it relieve, just close the valve enough to watch the pressure rise. If it doesn't rise then there is something rotten in Denmark.

 

[careyo63]

Rice patty water trashed my Org. cylinder screen, Had to replace it. Looked as though Someone Copper welded a new screen. So it had problems a couple times! The weld was pitiful and the screen showed signs of damage on that one, The Hyd Pan had 1 inch of Crisco thick dirty Hyd. fluid on the bottom. Super Nasty!! And Stank!! Rice Patty water no doubt! And my guess Whale oil. Common Hyd. fluid back then! be careful you don't Shear the Hyd. shaft key if you close that Valve I highly don't recommend doing that!