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