Rebuilding hydraulic cylinders

[robs660]

Where can I find a good reference on how to rebuild / repack the cylinders on my tractor. I have a ton of bad seals that need to be replaced. Since I don't use the back hoe in winter thought I would start there. Then move on to the loader

Thanks

 

[Willl]

Check out pages 31 thru 37.

https://www.forddistributing.com/as...l/509_511_Backhoe_Manual_OM575.pdf?1293662980

 

[kennyd]

You can also search in the hydraulic forum, LOTS of threads in there over the years on rebuilding cylinders.

 

[Craig Clayton]

When I worked on forklifts I got a the job in the shop of repairing multistage masts. It is easy to take them apart and have them shipped out for rechroming. The trick is putting the seals back in without ripping them as they have to moved over threaded sections. I found my simplest tool was a 30 thousand feeler gauge that had nice round and smooth edges. Think of it like a tongue depressor in that you can get in and help the seal move over sharp threads. I had a 100% success rate in the shop, and I think the other guys grumped. Just wet the area with hydraulic oil and it should work. Keep ( SHARP POINTY ) pick away from seals and O rings,
Craig Clayton

 

[Fxfymn]

Before you rebuild check Baileys surplus section for replacement cylinders. I bought two loader cylinders for $85.00 each. Don't know if you can rebuild for that.

 

[woodchuckie]

I found it very easy to lay the parts out in the same order and direction I took the out in. That way I knew that even though I was having trouble getting a seal in that it was the right way. What would have made it the easiest was to have a third hand. I repacked it as least a year ago and no problem yet.

 

[robs660]

Are there any trick tools to deal with the seals? I have heard some people use grease to help them along. Not sure if good or ad idea

 

[wdchyd]

Yes, grease is necessary.....

Just use caution, don't scratch seal surfaces with sharp oring picks (including inside gland/piston grooves where seals are installed)....

Polish everything a seals touches (including inside gland/piston grooves where seals are installed)...watch your leading edges where seals have to pass by (they should be dull/rounded)

Buy premium seals when avail.....(those orings/backups on piston head and inside glands can be updated to much better seals).....sometimes OEM seals are not the best.....

Clean, Clean, Clean.....then wash hands/tools ...lube and reassemble......pay attention to "Fit & Finish" and you'll do fine.....

 

[robs660]

Who makes the best quality after market seals. I was going to just buy kubota

 

[crazyal]

I've found a large pipe wrench and a big vise mounted to a strong table very important. On older cylinders I find the gland nuts unscrew really hard and have even broken the tool to remove them once. My friend with a sprinkler shop has a 4' aluminum pipe wrench that has gotten the job done more than once.

I haven't done a kubota cylinder yet so they could be different but my Case equipment has a plastic seal that wipes the rod. It's quite hard to put in since you need to compress it. I found if you warm it up it'll soften and you can get it in easier.

Like others have said, clean, grease, and be careful not to damage the new seals. Does Kubota or an aftermarket company sell a gland nut install/ removal tool? When you get the rebuild kit from Kubota have them make a photocopy of the parts breakout of the cylinder. You'll find it useful.