720 front end loader

Crwise70d · Mar 5, 2018

I have a 720 loader on my late model 4020. When tractor is running and loader valve is in neutrL,oil is passing through the valve. Does anyone know if it should have any oil going through the valve??

markct · Mar 5, 2018

Passing thru as in to the return port,
or passing thru and going out to a
cylinder when valve isn't actuated? And
what brand we talking here?

Randy Shoe · Mar 5, 2018

Not sure but I think it depends on whether your tractor has an open or closed center hyd system. You guys that know more about it correct me if I'm wrong, and believe me I've been wrong more than I'm right. LOL

JD Seller · Mar 5, 2018

I your talking about a JD 4020 with a JD 720 loader then the tractor is a closed system. So there should NOT be any oil passing through the valve when it is in a neutral position. Was the loader on a different model tractor before it was put on the 4020???? There are some models of JD tractors that are NOT closed center but they are not common. IF not then your valve is leaking internally.

cjunrau · Mar 6, 2018

I believe you are talking about a valve body that has been added to the tractor to run the loader.
If it is plugged into the tractors factory outlet, and the lever is tied back to allow you to use a 2 lever spool valve for loader, then yes there should or can be oil flowing through the valve when in neutral. Someone has added an open centre spool valve to a closed system. That can cause the oil to warm up faster and could potentially cause some problems if used for extended heavy work.
I would not worry about it as long as it works. If you put the tractor out in the field at full load for 10 hrs I would probably want to disconnect the loader spool, or untie the lever if that's how it operates. It is better to use open spool ad on if not sure if tractor is open or closed. If open centre and you use closed spool you cause the relief valve to run all the time and the oil will boil

Crwise70d · Mar 6, 2018

passing through the return port

Crwise70d · Mar 6, 2018

4020 is closed system. I don't think I should be getting any flow if they ha e the right valve. It is hooked to a scv,but I'm plumbing it into the hyd. Return system.

Crwise70d · Mar 6, 2018

I should have said the pressure and return system!!!

JD Seller · Mar 6, 2018

You should only have return oil if your moving a function lever. If you have oil when everything is in neutral then you have either a bad valve or the wrong type. DO NOT run it that way. You will starve the main hydraulic pump because the transmission pump can not keep up with the main pump. If you try running it this way your hydraulics will chatter all the time.

720 front end loader

Crwise70d

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markct

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Randy Shoe

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JD Seller

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cjunrau

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Crwise70d

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Crwise70d

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Crwise70d

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JD Seller

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