Lenar 254 II Hydraulic pump weak

[Greygoose]

Hi Guys-
My FEL is getting very weak,only works even half right if I am running at or above 2000 RPM,even then does not have near the lifting power it once had.The fluid is good and full,screen is clean and I have no leaks-I guess I have come to the conclusion that the pump must be wearing out.Just wondering if anyone can tell me if this pump is rebuildable?Thanks very much,
Mike

 

[Dave M7040]

The first thing you have to do is to buy a pressure gauge and quick coupler fitting like this one.

The gauge and fitting was about $30 at a local hydraulic shop.

If you have quick connectors for the hydraulic lines for your loader, remove one and plug in the gauge.

Rev engine wide open and move FEL lever to send pressure to the gauge and have someone read it if you cannot.
You could buy a length of hose with the gauge on one end and a quick coupler fitting on the other end and in that way be able to hold and read the gauge while sitting in the driver's seat.

The pump will not be re-buildable. The tolerances and cleanliness required are too high for anyone outside a specialized facility to perform.

The more likely scenario is that the pressure relief valve needs to be set but you wont know that until you do a pressure test.

Tell me about the lifting capacity of the 3 pt hitch. Usually the FEL and the 3 pt use the same pump although not always. If the 3 pt is strong then it may be the relief valve on the FEL control.

Don't go turning things trying to see if it will help without having a pressure gauge and instructions on how to make the adjustment. You can instantly break very expensive pieces.

Dave M7040

 

[Greygoose]

Thanks very much Dave,the 3 point uses the same pump as far as I am aware.I have a backhoe attachment and it has also gotten weaker over the last year-I have it removed now though.I'll see if I can get a gage and report back.Thanks again Sir,
Mike

 

[oldnslo]

Does the loader lift speed change significantly from being empty to lifting a load?

Was the speed change sudden or gradual over a period of time?

To really check a pump you should have a flow meter and pressure gauge. This lets you monitor flow vs pressure.

Problem is flow meters are expensive and getting them installed is challenging.

 

[Dave M7040]

Does the loader lift speed change significantly from being empty to lifting a load?

Was the speed change sudden or gradual over a period of time?

To really check a pump you should have a flow meter and pressure gauge. This lets you monitor flow vs pressure.

Problem is flow meters are expensive and getting them installed is challenging.

This is a question not a statement.
Would a new pump cost more or less than buying and installing a flow meter?

Can you rent flow meters for a small fee or is a large fee for a short time?
My experience in the hydraulic world is limited. My limited experience is that if a pump and hydraulic system has been working well and then deteriorates, a simple pressure test will confirm the condition of the pump provided the relief valve is not relieving. Is my logic flawed?

If I was going to buy a flow meter this is the most reasonable I can find. Are there better, more reasonably priced ones?

Another style from Northern Tool. There are always questions about the quality of the products from Harbor Freight. How is the Northern Tool stuff?

http://www.northerntool.com/shop/tools/product_36723_36723


Dave M7040

 

[CJONE]

Most shops will let you use one or do the test for a small fee. We don't charge anything as long as the customer buys the repair parts from us. The meters you are looking at do not provide a load [or restriction] so you have to operate something with the meter in place. If you are going to spend the money get one with a needle valve to provide variable restriction [load] But you have to remember when testing upstream of a relief you can apply pressure until you destroy something. Go to AW Lake and look at their Hydraulic flow analyzer this is just basically a meter with a needle valve and gauge. I build them here because of the high flow we usually need. Give them a call for pricing, I believe anybody can purchase through them but not 100% sure. CJ

 

[oldnslo]

This is a question not a statement.
Would a new pump cost more or less than buying and installing a flow meter?

Can you rent flow meters for a small fee or is a large fee for a short time?
My experience in the hydraulic world is limited. My limited experience is that if a pump and hydraulic system has been working well and then deteriorates, a simple pressure test will confirm the condition of the pump provided the relief valve is not relieving. Is my logic flawed?

If I was going to buy a flow meter this is the most reasonable I can find. Are there better, more reasonably priced ones?
Dave M7040

Dave,
General rule of thumb is that most operators won't notice 10 - 12% system degradation over time. Usually 15% or more people start to notice.

slow deterioration over time can be pump wear and or leakage elsewhere in the system.

Sudden deterioration: catastrophic pump failure (severely scored) or a relief is stuck open.

Yes flow testing equipment is expensive and I don't know if some shops will loan this type of equipment or not. For small "throw away" style gear pumps it may be less cost to replace the pump but it may not solve the problem.

To test the pump requires components like cjone stated.

To correctly test the pump you have to install the flow meter before any other valves so that you watch flow Vs pressure. If installed in parallel with a relief the relief could start passing flow making it look like the pump is bad.

 

[Greygoose]

Lot's of good info here-thanks Guys.I ordered a gauge and it should be here Tuesday.Do I have to bleed the small length of hose before attaching the gauge so there is no air in the test hose before I test the pressure?Thanks again very much,
Mike

 

[oldnslo]

Lot's of good info here-thanks Guys.I ordered a gauge and it should be here Tuesday.Do I have to bleed the small length of hose before attaching the gauge so there is no air in the test hose before I test the pressure?Thanks again very much,
Mike

No need to bleed the air out. Only caution is that it may spurt a little oil when disconnecting it since air compresses and even a small bubble can spit at you...

 

[Greygoose]

Okay Guys-
I got the gauge and hooked it up to one of the lines feeding the dump cylinders on the FEL.Ran engine up to full throttle (about 2500RPM) and got 1900lbs.Is that good?At about 1500RPM I am only getting about 800-900lbs.Thanks again very much,
Mike