Loader Kubota LA463 Loader Help

[StuartT]

Did you get a kubota hyd filter ?

Yes, both a Kubota brand hydraulic and HST. I am curious why you ask? I always appreciate being educated on my tractor.

 

[Peter 315]

Yes, both a Kubota brand hydraulic and HST. I am curious why you ask? I always appreciate being educated on my tractor.

The kubota hyd has the magnet on it ,Its what you want to keep the metal trapped

 

[StuartT]

The kubota hyd has the magnet on it ,Its what you want to keep the metal trapped

Well, there you go. I learned something. Thanks

 

[StuartT]

Would be nice if you document this!!! (Please!!!)

Your wish is my command.:dance1:

In the end, I rebuilt both bucket cylinders on my LA463 FEL. I needed to see the seal arrangement on the good cylinder in order to do the leaking one, which was dismantled when I got it back from the hydraulic shop. I am taking them to small claims court over this, but that is another story.

There are two main parts that have seals, wipers, spacers and/or expanders. The piston on the shaft and the cylinder head which the shaft slides through and which screws into the end of the cylinder housing. This cylinder head has an internal wiper and seal. The wiper, which provides dust and dirt protection, is relatively easy to pop out and replace. But the inner seal is a bear. Hard to remove and harder to get the new one back in. Eventually, I found that lubing it with hydraulic fluid and using 1/2" wood dowels from each end, I could dis-form it sufficiently to finally snap into its groove. For a while, I was not sure I could get it in, but it can be done with persistence.

The bigger issue was the primary seal on the piston. It is a hard plastic material and very inflexible. You need special tools according to the service manual, one to get it on the piston, and another to compress it so you can slide the piston into the cylinder. Messick's service department advised using hot water or hydraulic fluid to soften the seal, but that did not work for me. I finally used a heat gun, warmed the seal to the point I could just barely handle it without gloves, and stretched it by hand until I was able to force it over the piston. The expander, the wider looking seal on the right is slit and is no problem to get on.



Now you have to get it into the cylinder, but the seal is now oversized and sloppy on the piston. The solution, while it is still warm, tighten a hose clamp around the seal and let it cool. Then reassemble the cylinder, the piston will slide right on in. It will re-expand to its original size with a little time once inside.

And the last bit of information I have is to share: The panic I felt when once it was all back together, all new hydraulic fluid and filters installed, and my first operation of the bucket. The bucket would rotate up, but not hold position. It would sink back down over 10 or so seconds. Over and over I tried, but the bucket kept falling back. I finally went out to a pile of dirt and decided to put a load in the bucket to generate some hydraulic heat. I was sure those two plastic seals were not yet seating. Two dozen times I rotated that bucket and two dozen times is fell back down. And then, suddenly it stopped dead in its tracks while falling. I exercised it several more times and viola. No hits, no runs, no balls, no leaks, no smoke, no funny noises, no joke, no nothing. It was now rock solid. So what happened?

I am pretty sure the cylinders had not filled completely and needed all that exercise to purge all the trapped air. I just had not been smart enough to figure that out until after the fact. :mur:

 

[Gator6x4]

Your wish is my command.:dance1:

In the end, I rebuilt both bucket cylinders on my LA463 FEL. I needed to see the seal arrangement on the good cylinder in order to do the leaking one, which was dismantled when I got it back from the hydraulic shop. I am taking them to small claims court over this, but that is another story.

There are two main parts that have seals, wipers, spacers and/or expanders. The piston on the shaft and the cylinder head which the shaft slides through and which screws into the end of the cylinder housing. This cylinder head has an internal wiper and seal. The wiper, which provides dust and dirt protection, is relatively easy to pop out and replace. But the inner seal is a bear. Hard to remove and harder to get the new one back in. Eventually, I found that lubing it with hydraulic fluid and using 1/2" wood dowels from each end, I could dis-form it sufficiently to finally snap into its groove. For a while, I was not sure I could get it in, but it can be done with persistence.

The bigger issue was the primary seal on the piston. It is a hard plastic material and very inflexible. You need special tools according to the service manual, one to get it on the piston, and another to compress it so you can slide the piston into the cylinder. Messick's service department advised using hot water or hydraulic fluid to soften the seal, but that did not work for me. I finally used a heat gun, warmed the seal to the point I could just barely handle it without gloves, and stretched it by hand until I was able to force it over the piston. The expander, the wider looking seal on the right is slit and is no problem to get on.

View attachment 648801

Now you have to get it into the cylinder, but the seal is now oversized and sloppy on the piston. The solution, while it is still warm, tighten a hose clamp around the seal and let it cool. Then reassemble the cylinder, the piston will slide right on in. It will re-expand to its original size with a little time once inside.

And the last bit of information I have is to share: The panic I felt when once it was all back together, all new hydraulic fluid and filters installed, and my first operation of the bucket. The bucket would rotate up, but not hold position. It would sink back down over 10 or so seconds. Over and over I tried, but the bucket kept falling back. I finally went out to a pile of dirt and decided to put a load in the bucket to generate some hydraulic heat. I was sure those two plastic seals were not yet seating. Two dozen times I rotated that bucket and two dozen times is fell back down. And then, suddenly it stopped dead in its tracks while falling. I exercised it several more times and viola. No hits, no runs, no balls, no leaks, no smoke, no funny noises, no joke, no nothing. It was now rock solid. So what happened?

I am pretty sure the cylinders had not filled completely and needed all that exercise to purge all the trapped air. I just had not been smart enough to figure that out until after the fact. :mur:

Brave man. Congrats on a job well done. Thanks also for providing the how-to-do information.

 

[old and tired]

Your wish is my command.:dance1:...

:thumbsup: thanks, I hope to never have to do this!!! :laughing:

 

[jimainiac]

StuarT, thank you for explaining how you got the seals on the pistons. It's a bad feeling to get something apart and then find out it requires special tools to reassemble. I might have been able to figure out the heat gun to expand the seal (maybe), but that was a neat trick to compress it with a hose clamp while it was still warm.
In hindsight, would there have been a way to bleed the cylinders when they were back together before operating?

 

[Peter 315]

StuarT, thank you for explaining how you got the seals on the pistons. It's a bad feeling to get something apart and then find out it requires special tools to reassemble. I might have been able to figure out the heat gun to expand the seal (maybe), but that was a neat trick to compress it with a hose clamp while it was still warm.
In hindsight, would there have been a way to bleed the cylinders when they were back together before operating?

No , You just put the hyd lines on and cycle the pistons to force the air out that's it...........

 

[StuartT]

StuarT, thank you for explaining how you got the seals on the pistons. It's a bad feeling to get something apart and then find out it requires special tools to reassemble. I might have been able to figure out the heat gun to expand the seal (maybe), but that was a neat trick to compress it with a hose clamp while it was still warm.
In hindsight, would there have been a way to bleed the cylinders when they were back together before operating?

I agree with Peter. There is no provision for bleeding, like bleed ports or valves, and the manual says nothing about bleeding. Loosening a hydraulic line could result in a big surprise when the air gets evacuated and the fluid hits home. Cycling seems to be the only way. Thanks for the feedback.

 

[fried1765]

Here is an email from Messick's re the LA463 loader hydraulics.

Stuart,
Good afternoon.
I apologize, it does state to use special tools(slide jig and correcting jig) to install the expander and piston seal.
However, it instructs you or us as a dealer to make the tools.

We do not have these tools.
Our technician informs me that he would heat the expander in water or oil and install it manually into the piston groove.
He would then install the piston seal over the expander.
And then he would put the piston with seals in a refrigerator for a few minutes, which will shrink the piston seal over the expander
and allow the installation into the cylinder barrel.

I hope this helps, if you need more information, please let me know.

Thanks, Tim

Tim R. Marholz
Messick's Technical Support

P.S. He included pages S-14 through S-17 of the LA 463 service manual. View attachment 646071

MESSICK'S IS THE BEST !!!!
ALWAYS !!!!!