# JD 790 w/ 300 FEL, bucket drops before going up



## robertsmau (Nov 9, 2008)

The FEL has worked perfectly for years and I've never detached it. Suddenly, and most inconveniently, it now drops rapidly when trying to feather list anything. It's the same thing that's happening on this youtube video

[ame]https://www.youtube.com/watch?v=Ia-5eUZOu8g[/ame]

I've checked the fluid level, worked it excessively to try and "un-stick" anything and given it a visual inspection for any leaks or problems. Everything looks in order. Any ideas or trouble shooting tips?

Rob


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## FredM (Nov 18, 2015)

Hi robertsmau : Have you tried raising the boom to full height and then lowering this to ground level and lifting the front of the tractor with the rams and repeating this a number of times, while you have the boom raised dump the attachment/bucket and then crowd the attachment/bucket and do this a few times also, if you have air in the rams this should bleed the air out and then the air will travel back with the oil into the transmission and disperse out of the oil.

Failing that, you may have a problem with the control valve spools or even the pressure control valve, have never seen that though, mostly oil leak from hardened O rings on the spools.


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## sixbales (May 18, 2011)

Good morning Robert. 

The piston seals on your lift cylinders may be gone.


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## robertsmau (Nov 9, 2008)

I gave it a good up, down and all around and still no improvement, fluids clean and full.

If the seals went bad wouldn't I also be seeing leakage or a faster rate of leak down when under load? I don't see any of those symptoms. 

I'm thinking its in the SCV or a check valve somewhere. Not sure how to isolate that or where to check next


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## FredM (Nov 18, 2015)

robertsmau said:


> I gave it a good up, down and all around and still no improvement, fluids clean and full.
> 
> If the seals went bad wouldn't I also be seeing leakage or a faster rate of leak down when under load? I don't see any of those symptoms.
> 
> I'm thinking its in the SCV or a check valve somewhere. Not sure how to isolate that or where to check next


robertsmau ---- have you raised the boom a couple of feet off the ground with a load on /in the bucket and then let the boom sit at this height, if so, is the boom sinking when you do this ?, if this happens, it could well be a leaking cylinder seal, what happens when you crowd the bucket back and let the control lever return to the center position, if the crowded bucket holds then I would suspect leaking cylinder seal/s.


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## Hoodoo Valley (Nov 14, 2006)

FredM said:


> robertsmau ---- have you raised the boom a couple of feet off the ground with a load on /in the bucket and then let the boom sit at this height, if so, is the boom sinking when you do this ?, if this happens, it could well be a leaking cylinder seal, what happens when you crowd the bucket back and let the control lever return to the center position, if the crowded bucket holds then I would suspect leaking cylinder seal/s.


Even brand new, the economy John Deere tractors which includes the 790, will drift down fairly rapidly. My 990 drops down fairly quickly even with nothing in the bucket. Has since new.


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## robertsmau (Nov 9, 2008)

All other operation is completely normal. I just moved a 500lb load and once I had it lifted it never floated down or anything for about 10 min while I move it. I'm going to get a hydraulic guy out here to take a look because I think its in the control valve.


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