John Deere 400CX Loader cylinder failed - looking for suggestions

[sbeckwith]

I had the curl cylinder stop working when moving snow Christmas eve. (Why of course - perfect timing and no way to get parts)
The curl cylinders would not rotate up and of course - I believe it was around -1 degrees to boot AND I need this loader to feed 50 head of cattle.
So - I get it back to the shop to figure it out. I run the hydraulics to see if I can detect any heat in either cylinder and sure enough - one has heat. I pull the pin closest to the bucket to service the cylinder. I pull on the rod and to my surprise - it pulled right out of the cylinder... The bloody piston unscrewed from the rod.
So - Here is where I am - I removed the c-clip and had to pound the piece that holds the rod in far enough to insert the piece I made from sch40 pvc pipe in order to keep that part from engaging when pulling it back out. Problem is - I can't get piece to move back out - and the only method I have is a 3 lb slide hammer.
Any suggestions? Cattle are getting hungry and it's 2am and the dealership doesn't open till Tuesday.

I am going to grab some sleep - but I am thinking of plugging the lines to that cylinder and hope it will be strong enough to load some round bales into the feeders. Any thoughts on that?

On another note - I don't care for this design at all. Much more prefer the design where the cap is threaded onto the cylinder. Thanks for any suggestions while I go grab some zzz's

 

[nisaacs]

Maybe bolt a washer on the end of a piece of all thread or bend a hook on some 1/4 rod. If you still can't pull it out, maybe put the rod/all thread in a vice and use the cylinder tube as a sort of slide hammer. You will need something similar to pull the piston.

 

[dodge man]

Can’t help with the repair but do you have a neighbor that woukd help you out with his tractor?

 

[sd455dan]

Can you get the rod back in and the thread into the piston?

If so maybe hook up the lines with the other cylinder already extended then using the tractors hydraulics all the oil flow should push the piston and rod out of the cylinder body.

Probably one heck of an oily mess and I would think some force would have to be exerted against the rod to make sure the piston comes out with it.


but if it gets the piston out should be able to reassemble with a torque wrench and lock tight to be serviceable again.

 

[nisaacs]

Can you get the rod back in and the thread into the piston?

The piston is not threaded, it will have a nut that holds it onto the piston rod. Here is a generic picture.

 

[repete]

Not sure how efficiently it would work but have you thought about just plugging the lines to the failed cylinder (do not connect them)and operating with light loads in the bucket until you can tear down the failed cylinder?

 

[sd455dan]

Can you get the rod back in and the thread into the piston?

If so maybe hook up the lines with the other cylinder already extended then using the tractors hydraulics all the oil flow should push the piston and rod out of the cylinder body.

Probably one heck of an oily mess but if it gets the piston out should be able to reassemble with a torque wrench and lock tight to be serviceable again.

The piston is not threaded, it will have a nut that holds it onto the piston rod. Here is a generic picture.

View attachment 776384

Yeah I get that,

When I said" thread" it is because that is the first part of the rod that NEEDS to start into the piston hole.

The pressure is only what is needed to move the piston out of the bore

The piston has the internal oil seal

I thought the problem the OP is having is getting the piston out of the bore because the rod nut unthreaded. So he can rethread the nut and reasemble the cylinder. I have gone through cylinders on my old Ford 3000 New Holland 778 skid steer, My Koyker Rhino and on my 550 Ford TLB.

All I was suggesting was reinserting the rod through the piston hole and applying a little hydraulic pressure to get the piston to move out of the cylinder. Guys have had to do that when the rods get bent as well.

Maybe I misunderstood what the problem is. Is he also having a problem getting the Gland nut loose as well

 

[wdchyd]

You’ve already sent in the gland to install the plastic removal ring right?
Pull off the cylinder barrel from the tractor, stand it up on the ground, plug both ports, pour water in the gland hole nearly full, insert the hyd rod and pound it in with a dead blow or heavy hammer with only a few heavy hard hits.
With any luck the gland should pop out using the hyd pressure from the water.

 

[wdchyd]

……and, oh yea, before you fill with water reach in and push the piston head and nut to the bottom of the barrel. You don’t want to damage the piston, I’m sure the nut is already junk.

 

[sbeckwith]

Thanks all - some great ideas. What I have done is install caps on the line that feed the failed Hydraulic Cylinder for now. There is a risk of damaging the loader I suspect, so what I am doing is making sure the bale spear is properly positioned so I don't need to use the roll function other than dumping the round bale. So far - it is working until I get this cylinder repaired.

I managed to find a place that does nothing but repair hydraulic cylinders and..... they cringed when they seen it was a John Deere cylinder of this design. They have the tool I made and were actually pretty impressed with the job I had done and shared with me that they can't always get the cylinder apart even with this tool. They have tied these cylinders to I-beams to pull the internals out and have failed on some. They end up cutting the weld out on the head of the cylinder and pulling the internals out that way.

They said it is a great design to keep the cylinder compact - but does not lend to easy servicing. The one thing I found out is - this cylinder is restricted internally to the length of stoke, so I may be able to find a similar cylinder that is easier to service.

I really like the water idea mentioned above to create the pressure to force the retaining assembly out. I called and mention that to them and see what they thought. We got into a discussion, and they shared them using compressed air doing a similar thing that uhm... turn out to be less than safe... it turned it into a projectile when it left loose. Any who - they basically do the same thing using spent hydraulic fluid as a last resort before cutting the weld off and going after it that way.

If I ever come across a great Hydraulic Cylinder that is a good cross in the future, I will be sure and share it here.