Lenar 254 II Hydraulic pump weak

[Dave M7040]

Dave-yes,the valve,part number 23 is for certain the valve with the chinese writing on it.The knob under the seat for certain cuts off the power to the 3 point and directs it to the auxillary quick connect for the backhoe.I have no idea why there are numbers on it.
Mike

Mike
More questions as always.

Can you tilt the seat forward or someway get me some pictures of the back side of the valve under the seat so I can see what hose goes into it and out of it.

In the photo of the knob under the seat, there is a hydraulic cylinder or shock absorber. Can you clarify this plse.

In the parts material I do not see the valve under the seat nor any hydraulic lines to the backhoe. Do you have any other parts diagrams which would show this.

Your pressure reading at WOT was 1,900 psi. The number 10 MP on the valve with the Chinese writing on it converts to 1,450 so if that valve is indeed the relief valve you are already higher than you should be. This is why I am so reluctant to have you taking it apart and possibly shimming it.

Dave M7040

 

[Greygoose]

Dave-
I cannot get the seat tilted to get a photo-sorry.That is a shock absorber for the seat-no hydraulic line goes to it.The line from the knob goes into the case that the 3-point hithch lifting mechanism operates from.Something must not be right with that number because a Lenar dealer / mechanic told me that I should be getting 2200-2500lbs. ??
Mike

 

[Dave M7040]

Dave-
I cannot get the seat tilted to get a photo-sorry.That is a shock absorber for the seat-no hydraulic line goes to it.The line from the knob goes into the case that the 3-point hithch lifting mechanism operates from.Something must not be right with that number because a Lenar dealer / mechanic told me that I should be getting 2200-2500lbs. ??
Mike

Mike
Do you know anything about this Red River Company?
They claim to be able to provide you with a link to a downloadable operation and Maintenance manual for your tractor when you contact them by email.
Dave


Contact Us For Chinese Tractor Parts

Red River Parts Supply can provide you with the Operational and Maintenance manual for your tractor. Please email us with your tractor name and model (include model number and manufacturer) and we will send you a link for a downloadable copy of the manual.


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[Dave M7040]

Mike

I came across some info which seems to confirm my thoughts that the valve we have been looking at as the possible relief valve is in fact a flow priority valve for the hydrostatic power steering.


Read the description of the purpose of the Shunt valve in broken English.

PSU means power steering unit. Your hydraulic system is an open center design.

In your case after the steering system needs are met, the pump is being shared with other systems like the 3pt, backhoe and FEL.

In this spec table note the same letters FLD-F and then 6 stamped for 6 liters per minute going to the power steering unit
This one has a higher pressure than yours of 12.5 MP whereas your is 10 MP

What I think this means is the relief valve is somewhere else.

My logic is this, the shunt valve close to the pump provides a stable flow to the pump and a stable pressure of 10 MP.

The reason for this design is when you are driving fast and decide to raise the FEL while driving, the designers did not want you to loose control of your steering. Unlike your car or pickup, there is no connection between the front wheels and the steering wheel. On your car, if the engine stalled, you can still steer but with much higher effort. On your tractor, engine stalls, no steering period.

After the pressure supply leaves the shunt valve it is at a high pressure if you are using the backhoe or FEL or 3pt hitch. The relief valve for those things is somewhere further back on the tractor.

Do you have any other parts pages?

Dave M7040

 

[Greygoose]

Great info Dave,thanks very much.Well,I think we are moving forward since you told me you think the relief valve is somewhere else-I think I may have found it.Attached are some pictures from the parts manual again,and of that actual area of the tractor.What really caught my eye was part numbers 25-31 and 34-ESPECIALLY 30,"shims" and the notation after "As Required".This must be the relief valve??Thanks again so much,
Mike

 

[Dave M7040]

Great info Dave,thanks very much.Well,I think we are moving forward since you told me you think the relief valve is somewhere else-I think I may have found it.Attached are some pictures from the parts manual again,and of that actual area of the tractor.What really caught my eye was part numbers 25-31 and 34-ESPECIALLY 30,"shims" and the notation after "As Required".This must be the relief valve??Thanks again so much,
Mike

View attachment 499909View attachment 499910View attachment 499911View attachment 499908

Mike
Does your tractor have a hydraulic shuttle control?
If you are not familiar with hydraulic shuttle, once you are moving, the shuttle shift can be moved from forward to reverse without using the clutch.
Its purpose is to facilitate using the FEL going forward and backwards moving, material.

This question is very important because it identifies which one of two companies built your tractor.

I requested and received a complete set of WSM, parts and operators manuals just for asking at Red River based upon the assumption it was the model with the hydraulic shuttle.

Let me know asap and if correct and you have the hydraulic shuttle I will send you the material.

The WSM is a big file and I have just gone through it very quickly.

The bad news is in the relief valve specifications as shown in the page from shop manual.
10.5 MP

Not the news you were hoping for.
Perhaps I have the wrong tractor because you don't have the hydraulic shuttle.

Are you familiar with the term draft control as it pertains to a tractor.
A brief description. You have a two furrow plow in the ground and pulling it across the field.
The density and wetness of the soil will vary so the tractor will have to deal with the increased pulling load or it will just stall. You could keep raising and lowering the depth of the plow using the three point hitch lever. It would be a very tiring and frustrating job.

To over come this limitation, tractor designers realized they were already getting a signal back from the plow about how hard it was, at that moment, to pull it through the soil.

The top link. If you try and plow without a top link, the plow will just tilt forward and out of the ground. The top link, when plowing, is resisting a push from the plow. When you are raising the entire plow above the ground, the top link is being stretched by the weight of the plow.

By building a hydraulic valve into the attachment point of the top link, designers can sense how hard the plow is resisting being pulled through the ground and gradually and automatically raise and lower the 3 pt lower arms thus keeping the load or draft on the tractor engine constant.

The shims you are seeing may be part of that adjustment.

Dave M7040

 

[Dave M7040]

Mike
This may seem like a stupid question but..... the knob under the seat, why the numbers on it? Could this knob be to adjust the stiffness of the seat suspension and have nothing to do with the hydraulics. You describe turning the knob all one way or the other so having numbers makes no sense.

Part number 23 valve. Do we agree it is the component with the Chinese writing on it that we have been discussing?

Dave M7040

Mike
You have me completely confused with your answer to my question regarding the knob under the seat.

The knob under the seat for certain cuts off the power to the 3 point and directs it to the auxillary quick connect for the backhoe.I have no idea why there are numbers on it.

Now I find this in the operators manual.

◆ Suspension adjustment knob ( This is seat suspension)
Turn the suspension adjust knob to set the optimum suspension.

Again another stupid question perhaps but could it be possible the way you were shown how to operate things was by someone who did not know anything and just gave you BS and now because of that poor instruction you are doing things that don't control what you think they do.


Dave M7040

 

[Greygoose]

Sorry Dave-that knob is for the seat-the knob below that is the one that I use to power up the backhoe.I do not think I have a shuttle shift,it is a fully manual transmission.

 

[Dave M7040]

Sorry Dave-that knob is for the seat-the knob below that is the one that I use to power up the backhoe.I do not think I have a shuttle shift,it is a fully manual transmission.

The one further below the seat is just to control how fast the 3 pt arms descend when supporting a heavy load or even lock it in a position.
I do not believe it does what you think.

I will ask the Red River guy for the other manufacturers' manuals.

Can you plse photograph any tractor label, there might be one below the steering wheel.
Do you have any material relating to the backhoe or the FEL?

Dave

 

[Greygoose]

If you let that knob open,the three poiint hitch arms work and the backhoe does not.If you close it,it energizes the backhoe / external implement quick connect fitting.I know this for certain.I have no info on the backhoe,other than it is a John Deere #7.The FEL is a TAS ML160,built in Canada.
Mike