L785 Bucket control cylinder rebuild?

[JWD]

I have one bucket cylinder that is leaking badly. I've removed the cylinder from the machine and have managed to remove the bearing nut and the retaining ring. I had thought once I got to this point the piston and rod would simply slide out but it won't. Any help on what I'm missing greatly appreciated. Thanks - Justin

 

[SkidRoe]

I take it bearing nut and retaining ring, you mean that you have removed the gland from the rod end of the cylinder body?
Is the port open on the dead end of the cylinder or did you plug it with something to keep it from dripping after you removed the hose? Or are the hose and cylinder still attached to the machine?
If the port is not open, you will be drawing a vacuum by attempting to slide the piston out, and it won't move. The port has to be open to allow air in to get the piston out.
Hope this helps - SR

 

[JWD]

I take it bearing nut and retaining ring, you mean that you have removed the gland from the rod end of the cylinder body?
Is the port open on the dead end of the cylinder or did you plug it with something to keep it from dripping after you removed the hose? Or are the hose and cylinder still attached to the machine?
If the port is not open, you will be drawing a vacuum by attempting to slide the piston out, and it won't move. The port has to be open to allow air in to get the piston out.
Hope this helps - SR

Thank you for the reply. Yes I removed the large nut that uses the spanner wrench and then tapped the part labeled as cylinder head in the parts diagram this is the part the nut threads onto inward to loosen the snap ring and removed it. I did have the ports capped and removed the caps the rod will slide in and out but it seems that cylinder head is stuck it did move some. It's actually a little further out of the cylinder than it would be when the snap ring was installed. Is it ok to use the rod as a sort of slide hammer to knock the cylinder head out or perhaps pull it apart with a cable hoist? I'm trying to ask questions before tearing anything up LOL. Thanks

 

[SkidRoe]

Thank you for the reply. Yes I removed the large nut that uses the spanner wrench and then tapped the part labeled as cylinder head in the parts diagram this is the part the nut threads onto inward to loosen the snap ring and removed it. I did have the ports capped and removed the caps the rod will slide in and out but it seems that cylinder head is stuck it did move some. It's actually a little further out of the cylinder than it would be when the snap ring was installed. Is it ok to use the rod as a sort of slide hammer to knock the cylinder head out or perhaps pull it apart with a cable hoist? I'm trying to ask questions before tearing anything up LOL. Thanks

You definitely could try the slide hammer technique, I would be watching very carefully for movement between each hit. If it doesn't move within 5 hits, I would stop.
Fingers crossed - SR

 

[JDWY]

You definitely could try the slide hammer technique, I would be watching very carefully for movement between each hit. If it doesn't move within 5 hits, I would stop.
Fingers crossed - SR

Any chance you've got a cylinder like this that Mike10 replied about on a post further down?: "The cylinders are called ship in a bottle cylinders. Remove the hyd fitting from the cylinder. Push the rod down until you see the retaining ring, which is at the end of the rod, through the hole in the cylinder where the fitting was. Take a screw driver through the hole and pry the retaining from the end of the rod into the deep groove. The rod can now be pulled out. The seal is in the end of the barrel." That's definitely one I've never ran into.

 

[flyerdan]

Any chance you've got a cylinder like this that Mike10 replied about on a post further down?: "The cylinders are called ship in a bottle cylinders. Remove the hyd fitting from the cylinder. Push the rod down until you see the retaining ring, which is at the end of the rod, through the hole in the cylinder where the fitting was. Take a screw driver through the hole and pry the retaining from the end of the rod into the deep groove. The rod can now be pulled out. The seal is in the end of the barrel." That's definitely one I've never ran into.

With the seal end off, it would seem that the whole rod and piston should slide out, like a piston and rod from an engine with the head off.
Might want to check for something obstructing it, like a fitting screwed into the cylinder boss that extends into the bore. Wouldn't want to shear that off with a slide hammer, or mill a keyway into the piston.

 

[JWD]

With the seal end off, it would seem that the whole rod and piston should slide out, like a piston and rod from an engine with the head off.
Might want to check for something obstructing it, like a fitting screwed into the cylinder boss that extends into the bore. Wouldn't want to shear that off with a slide hammer, or mill a keyway into the piston.

I got it apart! After studying the diagram in the parts book and the disassembly procedure in the service manual and trying what all has been suggested on here I decided it was either extremely tight or something was already broken inside causing it not to come apart. So I hooked the rod end to my chain hoist and the cylinder end do the bumper of my truck and as I started to pull it moved about an inch so I took a brass punch and my hammer and tapped on the collar of the cylinder twice and it came apart. I don't see that anything inside apart from the seals to be damaged or worn so I think it was just that it was extremely tight. Just for anyone's future reference I was pulling up to an overhead beam not horizontally and also the slide hammer technique did not work for me because it felt that the air inside was not escaping fast enough and it was cushioning it right before it would actually hit. Will update once I'm done with the rebuild and let you all know how it went. Thank you for all the replies and help.

 

[SkidRoe]

I got it apart! After studying the diagram in the parts book and the disassembly procedure in the service manual and trying what all has been suggested on here I decided it was either extremely tight or something was already broken inside causing it not to come apart. So I hooked the rod end to my chain hoist and the cylinder end do the bumper of my truck and as I started to pull it moved about an inch so I took a brass punch and my hammer and tapped on the collar of the cylinder twice and it came apart. I don't see that anything inside apart from the seals to be damaged or worn so I think it was just that it was extremely tight. Just for anyone's future reference I was pulling up to an overhead beam not horizontally and also the slide hammer technique did not work for me because it felt that the air inside was not escaping fast enough and it was cushioning it right before it would actually hit. Will update once I'm done with the rebuild and let you all know how it went. Thank you for all the replies and help.

Thanks for the update, glad to hear you got it apart.
Cheers - SR

 

[Tazza]

Thanks for the update, glad to hear you got it apart.
Cheers - SR

I had one that rufused to move, i hooked up a bottle jack from the cylinder to the eye on the rod and pushed the pistone out. The last MESSY option is to hook up the bottom of the cylinder to the machine and operate the hydraulics and push it out. But that is gonna be mesy when the piston and rod come out.

 

[JWD]

I had one that rufused to move, i hooked up a bottle jack from the cylinder to the eye on the rod and pushed the pistone out. The last MESSY option is to hook up the bottom of the cylinder to the machine and operate the hydraulics and push it out. But that is gonna be mesy when the piston and rod come out.

Got it back together this last weekend and everything went together smooth and I'm happy to say no leaks! Thanks to everyone for the help.