Hydraulic Top Link fittings won’t stop leaking?

[LD1]

Its either a compression fitting or a flare fitting. I agree you need to take it apart and take a picture so we can see.

Thread sealer is gonna do NOTHING because that is a mechanical seal.
Also...cylinder packing is gonna do nothing.

As usual.....advice is only worth what you pay for it. Unfortunately that comes along with alot of bad advice.

 

[Duff]

Pull the valve off and check the ferrules on the tube.
Then check behind the ferrules, to see if the tube is cracked.

 

[hosspuller]

A photo of the whole cylinder inlet to outlet would be helpful. If the tube is a straight piece between the inlet and outlet... the design is faulty and will always eventually leak. There should be a bend in the tubing to allow cylinder length change.

 

[ptsg]

A photo of the whole cylinder inlet to outlet would be helpful. If the tube is a straight piece between the inlet and outlet... the design is faulty and will always eventually leak. There should be a bend in the tubing to allow cylinder length change.

I tend to disagree with this. Also, not sure what you mean about the bend?

There millions of cylinders using the same double pilot operated check valve with the hardline setup all over the world. It's part of a safety featured required on equipment. You see those on telehandlers, cranes, man lifts, top links, side links, all kinds of the equipment. It's there to prevent a load from falling in case an hose fails. The cylinder stays locked in place. It also won't let the cylinder drift by internal leakage for the control valves.

I'm sure the OP's issue is just a loose nut, cracked ferrule or hard line due to improper assembly. I've seen these things all smashed and still working fine.

Here is a picture of the entire setup for reference:

 

[hosspuller]

PTSG .. I am not referring to the valves. It's the tubing path. Notice the tubing bend between valve and port on this log splitter. The valve is fixed on the retract port. The "bend" allows movement between two fixed points (The 90 degree tube bend after the fitting helps too)

Any flex or expansion between the cylinder ports is stressing the tubing and fittings. I would not design or allow such an install. You may have different thoughts and practices.

 

[ptsg]

PTSG .. I am not referring to the valves. It's the tubing path. Any flex or expansion between the cylinder ports is stressing the tubing. I would not design or allow such an install. You may have different thoughts. Notice the tubing bend on this log splitter. The "bend" allows movement between two fixed points

View attachment 711572

I figure you were referring to the tubing and understand what you're saying. If there was even the remote possibility of that being a problem, I don't think they would approve this design for a safety feature. This is actually a safety feature required in loads of equipment all over the world. Some countries even require those for something as simple as a top link or side link.

Yes, the cylinder can expand, but so can the tubing, fittings and valve. Again, there millions of cylinders with this safety feature mounted on it and doesn't seem to be an issue whatsoever.

 

[Leejohn]

You 2 are both right in away. Short as the tubing is on this cyl is ok but when you get a long tubing then it dose neat a way for movement.

 

[Fixastuff]

Have you checked the torque specs for that size fitting? Some if the larger ones take a substantial amount, if your using a regular wrench you might just not be tightening them enough.