air in the FEL hydraulics

[kdm0811]

I have a BX24. When the FEL bucket is off the ground, I can rotate the bucket to and fro by hand. This is not because of play in the linkage but because the bucket rotation cylinder must have air in it. The piston rod moves about 2" with hand pressure on the bucket. What is the best way to bleed the hydraulic system? and why has this becme necessary?

Any advise?

Thanks.

 

[Wayne County Hose]

How is the cylinder power? Any weaker than in the past? Your problem could be worn piston seals. It could also be air in the cylinders. Did you do any hydraulic work on the curl system recently?

 

[DWW68]

To bleed the cylinder all you have to do is cycle it both ways and let go into bypass. My question would be how did the air get in there? I don't think air would be your problem. You may have warn seals or something allowing the fluid to pass.

 

[kdm0811]

The tactor is too new to have worn seals, and the FEL has never been repaired or removed. My ability to move the piston 2" by hand could not be due to leaking seals because I can move it that far in a fraction of a second. However, moving the piston through it's range of motion with the joystick does not seem to purge the air.

Any other thoughts?

 

[BXpanded]

Air is not the problem. When you move the cylinder, all the fluid (and air) is displaced from the cylinder and returns to the tank. The next cycle fills the cylinder with fluid.
Sounds like the nut that holds the piston on the end of the cylinder rod is loose. The cylinder will have to be dis-assembled to tighten. Not a terribly uncommon problem but can get very serious if not corrected quickly. The threads will strip at some point as things continue to loosen.

 

[Wayne County Hose]

The tactor is too new to have worn seals, and the FEL has never been repaired or removed. My ability to move the piston 2" by hand could not be due to leaking seals because I can move it that far in a fraction of a second. However, moving the piston through it's range of motion with the joystick does not seem to purge the air.

Any other thoughts?

Not too new to have bad seals, but from your description, the seals aren't the problem. Many FEL's do this. I think it's air being introduced into the rod end of the cylinder because of the way the bucket is when parked. When you park your tractor, try working the hydraulic controls after you shut off the engine to relieve any pressure. To get the air out now, just work the cylinders to their extremes a few times.

 

[justcountry]

I have to agree with BXepanded, As I have disasembled several cylinders, it seems logical that the piston nut is loose somehow? (maybe built on a Friday at 4:30) I don't see how air could be constantly reintroduced into the system without fluid visibly leaking out?

 

[Wayne County Hose]

The tactor is too new to have worn seals, and the FEL has never been repaired or removed. My ability to move the piston 2" by hand could not be due to leaking seals because I can move it that far in a fraction of a second. However, moving the piston through it's range of motion with the joystick does not seem to purge the air.

Any other thoughts?

There is not 2" of thread on the bottom of that rod, guaranteed.

 

[Eagleview]

I don't know what your tractor looks like , but if the hydraulic lines are not in a position to allow the air to come out completely ie. pipes attached at the bottom or side of the cylinder it could happen . Maybe if you lift the arms full height and then crowd the bucket both ways , the air may want to be purged more easily because of the changed angle .

 

[Wayne County Hose]

I was recently asked by a well respected tractor dealer why this happens to all the new tractors on his lot. Every one of them. He told me everytime they start a tractor to move it, the bucket will have a floppy curl until they move it hydraulically. I'll have to think about it. I have a theory if someone would like to try it out.