790/300 Loader slowly lowers by itself

[Twig52]

Where do I look to find why my loader will slowly lower itself. If I park the tractor (790) with the loader raised, it will drop over a few hours time. Have to adjust while using tractor also. Creeps down while running or shut down.

 

[jenkinsph]

Either the cylinder is leaking fluid past the seals on the piston or the spool valve seals are leaking. You may try using a floor jack or block of wood beneath the bucket to hold it in place while you unplug the hydraulic connections to the loader boom. Then back off the block or release the jack and see if it holds without leaking down. If it holds then the valve is the problem if it leaks down the fel cylinders are the problem.



Steve

 

[kennyd]

It is perfectly normal to have "slow" leakdown. JD even has a published "acceptable" leakdown amount paper.

Also...parking with the loader up is not a safe practice.

 

[jenkinsph]

It is perfectly normal to have "slow" leakdown. JD even has a published "acceptable" leakdown amount paper.

Also...parking with the loader up is not a safe practice.

What you posted is true but it depends on how fast it is leaking down when trying to do loader work.


Steve

 

[Twig52]

If I am running the tractor and have 500 lbs in loader it drops about 1" per minute. Thanks for the replies so far. Have not had the chance to diagnose it further yet.

 

[Phineas7]

That sounds about like mine.

I think it's the valve. If it were the cylinder, it would most likely be one or the other and as it dropped, it would bind.

It is annoying.

On my center link cylinder, it has a check valve. It never moves.

 

[OtterBrookStables]

My 790 used to do this as well. Nothing drastic, but a slow bleed over time. This is normal. My new 4120 actually has a hydraulic lock on it to prevent bleed down.