# Long 680 Hydraulic Cylinder Replacement



## goebelmj (Aug 13, 2021)

My Long 680 has major lift problems and I suspect a bad hydraulic cylinder/piston/seal rings. 

Is there any trick to disassembly and replacement of the cylinder and piston? Any help would be greatly appreciated.

Thanks all in advance,

MikeyG


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## BinVa (Sep 21, 2020)

If you can post a picture of the upper end of the cylinder…might be easier to determine disassembly. For extraction of the ram, I let the hydraulics push it out…a little messy but works. The biggest problem you may face is removing the packing nut at the rear of the ram. Sometimes takes a HD impact gun to get loose. B.


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## goebelmj (Aug 13, 2021)

This is the only pic I have as I haven't torn into it yet.


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## BinVa (Sep 21, 2020)

I'm not seeing the head of the cylinder. But the question was, there are several ways to hold the head to the cylinder tube...could be threaded, ring in groove or even welded. But once the head and ram are removed it's pretty straightforward. Replacement is done by lubricating the seals and rings and carefully inserting the ram. B


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## Fedup (Feb 25, 2014)

BinVa said:


> I'm not seeing the head of the cylinder. But the question was, there are several ways to hold the head to the cylinder tube...could be threaded, ring in groove or even welded. But once the head and ram are removed it's pretty straightforward. Replacement is done by lubricating the seals and rings and carefully inserting the ram. B


I think you're missing the point here. He's not asking about a conventional hydraulic cylinder. It's the three point lift cylinder that's in question.


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## BinVa (Sep 21, 2020)

Thank you for correction.... I did miss speak thinking that tractor had an external lift cylinder. Sorry to have created any confusion. B


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## goebelmj (Aug 13, 2021)

BinVa said:


> Thank you for correction.... I did miss speak thinking that tractor had an external lift cylinder. Sorry to have created any confusion. B


No problem. I have a 360-460-510 service manual but it's a little cryptic. From what I know now, it appears I can remove the head and the lift piston can be removed fairly easily. I'm hoping the cylinder is not scored.


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