Lenar 254 II Hydraulic pump weak

[Dave M7040]

I tried adding one at a time until I could no longer fit any more shims in it Dave-no change in pressure-still 1900lbs.I think I am just going to order a new pump.
Mike

Mike
Before deciding you need a new pump, why not test the old one in place.

First, you never want to cut off the output of the pump completely because to do so will destroy it.

Disconnect the pump from the valve below using the quick coupler.

Install a Tee on the pump outlet with your new gauge in one leg of the tee.

On the open end of the tee, install a hydraulic valve, not a water valve but the same style as an outside faucett, one where you can choke the flow slowly. Run the outlet of that valve back into the tractor or even a bucket for this very short test

With the tractor running slowly, restrict the flow out of the pump with the valve watching your pressure gauge. It will increase in pressure. Don't go over the 2,500 psi you have been told is the normal limit.

Don't pump all the oil out of the tractor and run the pump dry. 33 liters per minute is a lot of oil!

If you see 2,500psi out of the old pump, buying a new pump is not going to solve anything except slim your wallet.

Dave M7040

 

[Leejohn]

If it was me I would not be useing any kind of water valve for a test like that.

 

[Dave M7040]

If it was me I would not be useing any kind of water valve for a test like that.

Water valve was NEVER suggested. Please re read my post.

Mike(Greygoose) and I have been on a long journey with this issue. Having Chinese labels translated to learn his tractor had a Single Channel hydraulic shunt valve was, and on and on............

Dave m7040

 

[Leejohn]

I do see where you said same style as an outside faucett. Are you meaning a gate or globe valve?

I have been reading the thread all along and I see the trouble you are having.

 

[Greygoose]

Thanks Dave,good idea.

 

[Dave M7040]

I do see where you said same style as an outside faucett. Are you meaning a gate or globe valve?

I have been reading the thread all along and I see the trouble you are having.

Leejohn.

First I apologize if my first reply to you was a little too abrupt. Have serious pain issues and live on opioids.... so at times like a bear with a sore foot.

The ideal valve for this testing is a needle valve where the adjustments in flow can be done in minute increments. Hydraulic needle valves can be hard to find and expensive.

The gate valve, I have never seen in outdoor, or sill faucet applications because they usually leak as they rely on the usually brass gate to seal to another metal surface. Gate valves don't have a
linearity when it comes to change in flow versus position of the hand-wheel. First as you turn the hand-wheel there is no change in flow and then it suddenly jumps.

The globe valve is the most reasonable alternative, if a hydraulic one can be found locally. Alternatively, a fixed orifice plate could be made by Mike, as he is a machinist, to restrict the flow thus forcing the pressure to rise for measurement. He could alter the engine speed and as the flow increases through the orifice plate, the pressure should rise if the pump is OK.

Dave M7040

 

[Greygoose]

Wow,so I should not have used brass waterpipe fittings to adapt the lines to my gauge??Woops.

 

[Dave M7040]

Wow,so I should not have used brass waterpipe fittings to adapt the lines to my gauge??Woops.

Mike
I should have made certain you did not do that. I mistakenly assumed, since you had to buy the gauge at a hydraulics place, you would have bought the bushings and adapters there at the same time.

Do you know about the dangers of small leaks from say a hydraulic hose? The natural reaction is to put your hand above a tiny jet of spray to confirm it is leaking. In doing so you have injected into your body the leaking oil. Most tractor manuals contain cautions about doing this and show how you hold a piece of cardboard over the spot to determine if there is a leak. Should you ever inject high pressure anything into your skin, even if it is water from a pressure washer, get to a hospital immediately. The Chinese have a large population so don't seem to be as concerned with losing one to a tractor incident.
This material is from a Kubota manual. Never saw in the Lenar manuals.

Please, if you decide to test your pump as I suggested but before you do, send me a couple of photos so I can be more careful you are doing nothing dangerous.

Dave M7040

 

[Dave M7040]

I do see where you said same style as an outside faucett. Are you meaning a gate or globe valve?

I have been reading the thread all along and I see the trouble you are having.

Leejohn

I have all available, manuals for the Lenar and could send you the link to download them? Interesting reading, almost complete lack of info on some topics.

Dave M7040

 

[Greygoose]

And I did just notice a crack in one of the brass adapters.Thank God I don't have a chunk of brass in my brain!Wow,good info here,thanks again Dave.Again I buy all of the tees,adapters,valve,etc.,I might just be better off to haul the tractor to a heavy equipment place and have them check the pump pressure for me right off the pump-I wouldn't think they would charge me too much. ??
Mike