Hello, new to this forum. I have a 2004 ls160 that the boom over time has lost power. It will lift the grapple slow empty at 100% rpm. I was told the gear pump was weak but the bucket cylinders and the grapple arms seem fine, the bucket cylinders will lift the machine off the ground with no real effort. the fluid level is full and the boom pivot point are free. any help would be great. Thanks
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skidsteer.ca
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How many hours on it?
As you may know all 3 of these circuits use the same pump and the same relief valve, the only way the pressure to one of the 3 circuits would be low is if the foot pedal is not fully stroking the spool on the valve. You can pull the cover between your feet and verify the spool movement, it should be equal to the spoold for the tilt and Aux.
Now you say the pump is weak. Was it flow tested under pressure at a shop to determine this? If it is weak you should notice its performance drop as the hydraulic oil temp come up to normal (130- 140f in my Canadian climate).
Assuming the spools are fully stroking, my guess is it takes less pressure to move the bucket dump cylinders and the grapple then it does to lift the boom, and thats is why you see the limitations of the pump with the boom function.
You can hook a guage in your aux and the relief pressure should make it to 2500-2600 psi.
If it makes 2500 cold but not hot then your pump is weak. If it won't make 2500 cold, then the pump is shot.
Of course the proper way to verify this is to conect your aux hydraulics to a flow tester ad see what volume of oil the pump puts out with 1000 psi load on the circuit. it should be 15.5 gpm with the engine at 2900 rpm.
If the temp does not have any bearing on the pressure, then it could be you have a weak relief valve, these are not adjustable and need to be replaced.
More info is here.
http://www.mediafire.com/?ov9zqt7xwtl
Ken
As you may know all 3 of these circuits use the same pump and the same relief valve, the only way the pressure to one of the 3 circuits would be low is if the foot pedal is not fully stroking the spool on the valve. You can pull the cover between your feet and verify the spool movement, it should be equal to the spoold for the tilt and Aux.
Now you say the pump is weak. Was it flow tested under pressure at a shop to determine this? If it is weak you should notice its performance drop as the hydraulic oil temp come up to normal (130- 140f in my Canadian climate).
Assuming the spools are fully stroking, my guess is it takes less pressure to move the bucket dump cylinders and the grapple then it does to lift the boom, and thats is why you see the limitations of the pump with the boom function.
You can hook a guage in your aux and the relief pressure should make it to 2500-2600 psi.
If it makes 2500 cold but not hot then your pump is weak. If it won't make 2500 cold, then the pump is shot.
Of course the proper way to verify this is to conect your aux hydraulics to a flow tester ad see what volume of oil the pump puts out with 1000 psi load on the circuit. it should be 15.5 gpm with the engine at 2900 rpm.
If the temp does not have any bearing on the pressure, then it could be you have a weak relief valve, these are not adjustable and need to be replaced.
More info is here.
http://www.mediafire.com/?ov9zqt7xwtl
Ken
Thanks, I will go get the the things I need to check the pressure at the aux ports. I was talking to a friend of mine that said the pump was weak he has had more hydraulic experiance than I have. But he did not know how to test the sys the proper way. Now I know how to check it and be more possitive. All the New Holland dealers close have gone out of business and the closest one is over a hundred miles away and are not forthcomming with any info when you call to ask technical questions. I am glad I found this site and all help is really appreciated. Thanks alot.
Sorry, the hours are 5155 and all has been great untill this issue all maint has been performed before it was due and has always served well. engine still runs like a top and overall machine looks 90% everyone tells me I worry to much about little things.Little things if not attended to lead to much bigger costly things.
Earthwerks Unlimited
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The next time it does it, put your hand on the pump and see if it's too hot. If someone replaced the pump with an aluminum-housed pump, when it gets hot the housing expands and loses internal sealing. For too hot oil, be sure the oil cooler is not restricted with debris and that the fan belt is tight.
I finally got time to test sys at aux ports cold 1500 psi at 100% rpm and drops fast the longer you hold constant pressure, 900 psi hot. I guess I will be finding a pump online any suggestions on where the best place to buy?
Thanks for that link they where 100.00 cheaper than anyone else and it is a Eaton pump not aftermarket. Thanks, John
Earthwerks Unlimited
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- Dec 21, 2007
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They're nice guys there--though they don't return calls like they say they will--I wanted price on tires. Sloppy business practices are my pet peeve.
And they don't always tell you those prices COULD be for REBUILT unit--you have to ask.
A rebuild kit for a pump is less than $40. And takes less than a half hour to do start to finish.
Ask them what you're paying for.
Got the pump Friday it is a new Eaton pump not rebuilt that would have upset me because I asked that question when I ordered it. My pet peeve is hearing people chewing there food.
My bosses do that! one was *feasting* one day and as he was SHOVELING it in, it was falling out.... Was rather gross, as well as the noises... Those are the times i find a reason to be somewhere else at lunch time.
