Leaking hydraulic cylinder

RayCo · Apr 14, 2023

One of the cylinders that swings my backhoe started spraying hydraulic fluid today out the end of the (forgive my ignorance on terminology) of the cylinder case where the ram comes in and out. In my brief glance, I thought, "Hmm, perhaps this is a cap on the end of the case that comes off and simply needs a new gasket." Then I thought, "No, you got this new, bigger machine, so the days of simple fixes that you were used to on your little Kubota are over. Expect this to cost you lots of money because you probably don't have the tools needed to deal with it." For all I know, the cylinder has to come completely out, which is way outside of what I'm equipped to do. But, is there anyone here who can offer insight on the path forward to fix a hydraulic cylinder with a really bad leak?

Case 580 Super L backhoe swing cylinder
Picture:

Richard · Apr 14, 2023

I'd contend you can do it yourself IF you have some tools.

I TOTALLY removed my (I think they're called trunions?) anyway, totally removed them and it was a MAJOR pain in the butt....

Of course, after they were off, it dawned on me that I might have been able to:

1. Swing bucket to side
2. Disconnect rod from hoe and retract it
3. Remove rod/ram from cylinder
4. Put new gaskets back in
5. Reverse process

To get to these, I think you have to pull entire guts out and these are the hardest to deal with as you might have to remove the piston.

So.... just replace EVERYTHING in there, put back and repeat process on other side while trying to keep cylinder on machine.

This happened VERY soon after I had shoulder surgery so I was essentially doing this with one good arm and one weak arm.....so I used the straps to become a third arm. I had to hold BOTH cylinders up in the air while also then holding the plate UNDER them while then, putting the bolts in that sandwiched everything together.

Of course, THEN it dawned on my that I could have probably done same just by swinging bucket out of way.

(storm just hit, not sure pictures are going to post)

Richard · Apr 14, 2023

dfkrug · Apr 14, 2023

RayCo said:
For all I know, the cylinder has to come completely out, which is way outside of what I'm equipped to do. But, is there anyone here who can offer insight on the path forward to fix a hydraulic cylinder with a really bad leak?

Only remove the cylinder if you have to take it to a shop.

If DIY, leaving the cyl attached at the trunnion helps you hold on to it when unscrewing the gland (cap).

Remove the rod end pin and pull out the rod and piston, Sometimes you have to use the rod like a slide hammer to get the cap and piston out. Open the hose connections first, at what ever end is easier to access.

You need to replace at least the rod wiper and rod seal. The latter is much easier if you buy the cheap special tool. Replacing rod seal is much easier for these big cyls vs small ones. I am doing an old Kubota cyl now with 25mm rods. Much harder to get U-cup seal in there.

Getting the piston nut off is also difficult. You can use the rod end pivot on the backhoe to hold the rod when you take a breaker bar to the nut.

Good luck. You can do this.