Lenar 254 II Hydraulic pump weak

[Dave M7040]

I found this WSM online for Mahindra 3 series. I am now going through it and it says for this model of Mahinda the hydraulic pump is an EATON which is good news if that is what you have because EATON's pumps are world wide and it is not an obscure pump from China. Further the relief valve setting is 200 bar which is 2,900 psi

It might be a good thing to have because, although it may not exactly be your tractor, some of the info may be very relevant.

It does say if the relief valve is suspect it has to be replaced. I have not found any info yet on adjusting it.
I want to know how closely you think it matches your tractor

This is taken from the Mahindra owning and operating section of the forum


Default Can anyone make use of this 35-series service manual?

Found an old disk in bottom of my computer bag that has this service manual on it. I requested it when I bought the ill-fated Mahindra tractor a few years ago. If anyone can use such a manual here it is:

I am not sure if I'll get spanked for providing a download link but I guess time will tell.
MEGA
I hope it's useful for someone.

When you download this manual, go to page 360 approximately and look at the excellent color cross sections of the major components. I am very impressed with how they explain the operation of the transmission, differential, on and on.
Tell the MEGA site to download through your browser which is what I did.
Dave M7040

 

[Dave M7040]

Mike
If the number I think is 10.5 is actually 19.5 MP then that would mean 2,855 psi so if that is correct then your pressures are way low.

I been thinking about how to proceed in the absence of any real WSM numbers.

The natural tendency is to increase the pressure by turning in an adjustment screw, stud or bolt.
I think what you do once we feel that the device I marked with the red box is the relief valve, we start by lowering the pressure just to confirm we are controlling the pressure with what we are touching. Once we know we are at the right place, then you can decide if you want to take the risk raising it.

It there anything on the end of that part that looks like and adjustment with a lock nut? Plse take photos.

Dave M7040

 

[CJONE]

Hi Dave, is the valve you have bracketed in red the first valve in line on the downstream side of the pump? If so it looks like the small plug to the back of the pic to the left on the valve "may" be the relief. The pump is a DIN spec mount I believe and all of my din pumps are rated at least 2500PSI to 3k. Do you have a PN on the pump? I see a tag on the back. Your idea on lowering the relief first is a good one, It usually just takes a 1/8th of a turn to see a pressure difference. So it should be obvious fairly quick. I wish we could get a print od the system or a full pic of it. Nothing like being there! 2500psi is common on these small tractors for the hydraulic system, I believe mine is set to 2600 so this one at 1900 would be the reason the loader is weak like you are saying. BUT why is it turned down so low? I have see broken springs in these reliefs before so you may want to check that also if it is a spring style set up and not a piloted relief. Just a idea. CJ

 

[Dave M7040]

Hi Dave, is the valve you have bracketed in red the first valve in line on the downstream side of the pump? If so it looks like the small plug to the back of the pic to the left on the valve "may" be the relief. The pump is a DIN spec mount I believe and all of my din pumps are rated at least 2500PSI to 3k. Do you have a PN on the pump? I see a tag on the back. Your idea on lowering the relief first is a good one, It usually just takes a 1/8th of a turn to see a pressure difference. So it should be obvious fairly quick. I wish we could get a print od the system or a full pic of it. Nothing like being there! 2500psi is common on these small tractors for the hydraulic system, I believe mine is set to 2600 so this one at 1900 would be the reason the loader is weak like you are saying. BUT why is it turned down so low? I have see broken springs in these reliefs before so you may want to check that also if it is a spring style set up and not a piloted relief. Just a idea. CJ

Mike and c.c. CJONE

Mike
A friend with a Chinese wife translated the Chinese characters on the metal label
Lenar Tractor valve Chinese translation

From the top:
Single-channel stabilized shunt valve
Model FLD-F 6
Set the pressure 10 If this is 10 MP then it is 1,450 psi
Serial number 03090602
Bottom is the name of the factory. the Zhenjiang Hydraulic Parts Factory

I need to see the end of the part with the nameplate on it if there is any sort of adjustment there.

I still need a scan or photo of the parts diagrams which have the hydraulic components.

I don't yet know what a Single=channel stabilized shunt valve is. Every search I do comes back with medical reference. Not much luck googling Zhenjiang Hydraulic Parts

Dave M7040

p.s. slow progress but at least still moving forward.

 

[Dave M7040]

Mike
A forum member provided this link which to me explains the connection between Lenar and Mahindra.

Plse look at all the info and specs for the 254-II

Lenar | Tractor & Construction Plant Wiki | Fandom powered by Wikia

Dave M7040

 

[Greygoose]

Got it,thanks Dave.I am wondering if I could just take that round cap off of that valve (it does have a nut on it to remove it) and see if there are any shims inside it or ??? I am a machinist and could make them I am sure to shim the spring tension a little but I don't even know what is in there! lol
Mike

 

[Dave M7040]

Mike
I am still thinking on the next step.,

Can you send me the parts book page by taking a photo.
Look at the link to the Mahindra comparable to Lenar and tell me what you think. The link was in my post #26. If we can find a Mahindra which seems to ahv the same design hydraulic system it would help..

The Chinese factory whose name was on the shunt valve seems to no longer exist.

In the hydraulics section of this forum was a wizard who has backed away from participating but I may try and track him down to see if he knows what a "Single stabilized shunt valve is."

I am trying to understand why the output line from the hydraulic pump is a wire wrapped rubber hose plugged into the single stabilized shunt valve with a quick disconnect.

Do you ever disconnect that joint? My fear would be that the pump output would be dead ended and with no relief valve between the pump and quick connect coupling the pump is instantly destroyed.

Would you please go back and look for questions I asked you which have not been answered by you. One example would be what do you do to have the backhoe receive hydraulic flow and if there is something you do does the FEL stop working or the power steering stop working.

Are there any identify info on the pump?

Dave M7040

 

[Greygoose]

Hi Dave,here are some additional photos for you out of the parts book.I have no idea why the valve is on the steering page and the pump is on the hydraulic pump page,but at least we know now that it is the valve.I took a photo of the parts list and it says that it is a valve.The other photos show the knob under the seat to get flow to the 3 point lift or the quick connect plug to run the backhoe.You shut the knob off to direct flow to the fitting for the backhoe and open it to direct flow to the 3-point liftbars.The FEL nor the power steering are affected by either position of the rear knob.The lever for the 3-point hitch to raise and lower is also in a photo.The low pressure return line for the backhoe goes into a barbed fitting tapped right back into the gearcase,as the transmission is also lubricated by the hydraulic oil.I have never disconnected the quick connect to the valve from the pump.Nothing on the pump as far as ID.Thanks again very much,
Mike

 

[Dave M7040]

Hi Dave,here are some additional photos for you out of the parts book.I have no idea why the valve is on the steering page and the pump is on the hydraulic pump page,but at least we know now that it is the valve.I took a photo of the parts list and it says that it is a valve.The other photos show the knob under the seat to get flow to the 3 point lift or the quick connect plug to run the backhoe.You shut the knob off to direct flow to the fitting for the backhoe and open it to direct flow to the 3-point liftbars.The FEL nor the power steering are affected by either position of the rear knob.The lever for the 3-point hitch to raise and lower is also in a photo.The low pressure return line for the backhoe goes into a barbed fitting tapped right back into the gearcase,as the transmission is also lubricated by the hydraulic oil.I have never disconnected the quick connect to the valve from the pump.Nothing on the pump as far as ID.Thanks again very much,
Mike

View attachment 499629View attachment 499630View attachment 499634View attachment 499632View attachment 499633

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

 

[Greygoose]

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

 

[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.


How to Order:

You will need the factory part number (and description) to order the correct part for your tractor. In most cases, Red River Parts Supply can provide you with the Operational and Maintance 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. In order to avoid ordering the wrong part we will need Part Name, Part Number, Item Number and the Page Number from the manual. You will then receive a quotation via telephone and/or email. Please note: manufacturers sometimes make part changes to improve performance, and do not utilize unique part numbers, in these cases it is helpful to provide pictures of the part to be replaced to resolve indentification issues.
Technical & Mechanical Issues and Questions:
Red River Parts Supply has technical expertise available to answer your questions. Please contact us regarding your Chinese Tractor Parts needs and we will help you find the best solution.

Red River Parts Supply Company, LLC

319-892-3354 office
Email: Parts@rraparts.com

 

[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