Hydraulic Cylinder Leak Down on Box Blade???

[KWentling]

No, the cylinder is retracting when it settles down. If you look at my picture and expand it you can see the rod is facing down and is connected to a clevis which is welded to a horizontal pin. The lever to raise the gang scarifiers and this clevis for the cylinder are both welded to this pin, It has to be air in the cylinder or lines since it would do this with the couplers unplugged and no leaks.

Right you are. Has to be air then.

 

[Piston]

I did look at the inside of the cylinder and made sure everything was clean and neat. I'm going to take it apart again now and plug up those ports. I really don't think it's air only because it was doing the exact same thing before I took everything apart.

Wish me luck haha.

 

[Mace Canute]

A hydraulic cylinder has less oil volume on the rod side of the piston than on the opposite side and this makes it impossible for it to retract if it's uncoupled IF there is just oil on both sides of the piston and no air. In fact, you could remove the piston and it still wouldn't retract if there was only oil in it. There has to be air in it which compressed as it retracted.

 

[jenkinsph]

I did look at the inside of the cylinder and made sure everything was clean and neat. I'm going to take it apart again now and plug up those ports. I really don't think it's air only because it was doing the exact same thing before I took everything apart.

Wish me luck haha.

You could drill a hole through the piston and it would not make it leak down if there wasn't air in the system.
How much time have you spent trying to get the air out of the system. I would not tear it down again.

 

[Piston]

I just tore it apart again (surprisingly quick now that I've already done it).

I purposely left the hoses connected and didn't drain the fluid. As I unscrewed the rod cap and started to pull the rod out, I could hear a hissing and gurgling coming from one of those ports. I was pretty easily able to pull the entire rod out of the cylinder with all the fluid still in there, only because of this leak in the port I assume.

I unscrewed the set screws, cleaned all the oil out of the ports and blew it dry with compressed air, filled it with JB Weld (yup, I did) and then screwed the set screws back in watching the JB Weld come out the other end of the ports. I also caked the threads with JB Weld. I'm going to let it sit for 24 hours and put it back together tomorrow night for a test run.




I did find this little fella in there...

 

[4570Man]

I've got a forklift with air in the cylinder. It's spongy, but doesn't leak down terribly quickly. It's had air in it for over a year.

 

[bigdeano]

In post #15 the picture that shows the end of the shaft looks likes some kind of wire or burr is coming loose and is curled around. It looks like the little piece you found.

 

[ovrszd]

I could only add one video per post, this is the one with the hoses disconnected from the tractor...

Good example. There are several members on TBN that will tell you that is impossible.

We'll see if they show up and offer an explanation.

 

[Fallon]

Good example. There are several members on TBN that will tell you that is impossible.

We'll see if they show up and offer an explanation.

The difference between theory & practice is in theory everything works exactly as it should, however in practice it doesn't.

In hydraulics leaking down its usually loose seals letting in air or air in the cylinders.

 

[ovrszd]

The difference between theory & practice is in theory everything works exactly as it should, however in practice it doesn't.

In hydraulics leaking down its usually loose seals letting in air or air in the cylinders.

In this case it would have to be a leaking ram seal letting air into the barrel to allow the cylinder to collapse??

Why doesn't that failing seal leak oil?