Leak at cylinder fitting

L35

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I have a minor leak at a fitting on one of the backhoe cylinders. I haven’t had one of these apart before though I did look at the parts breakdown and it appears there is a oring for the Allen head bolt but nothing for where it’s leaking. It looks a little cockeyed like it may of bumped in something at one point. Does anyone know if they are welded or brazed to the cylinder tube or do they come off if you undo the Allen head bolt?

8A224750-6F93-49B0-9AFA-E60CA7CA0976.jpeg
BEFB6176-33E4-4D72-AC25-5DAC35D201FC.jpeg
 

TheOldHokie

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I have a minor leak at a fitting on one of the backhoe cylinders. I haven’t had one of these apart before though I did look at the parts breakdown and it appears there is a oring for the Allen head bolt but nothing for where it’s leaking. It looks a little cockeyed like it may of bumped in something at one point. Does anyone know if they are welded or brazed to the cylinder tube or do they come off if you undo the Allen head bolt?

View attachment 126238 View attachment 126239
Dont know for a fact but looks like a banjo fitting and it should come off when you remove the special bolt. Better have replacement seals on hand before taking it off.

Dan
 

L35

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Here’s the part breakdown on messics


76933C09-3978-49BB-BBE5-9F63151804F1.jpeg
 

TheOldHokie

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I have a minor leak at a fitting on one of the backhoe cylinders. I haven’t had one of these apart before though I did look at the parts breakdown and it appears there is a oring for the Allen head bolt but nothing for where it’s leaking. It looks a little cockeyed like it may of bumped in something at one point. Does anyone know if they are welded or brazed to the cylinder tube or do they come off if you undo the Allen head bolt?

View attachment 126238 View attachment 126239
Scratch what I said. Parts diagram shows a plug and o-ring so not a banjo. Elbow looks like it might be screwed into bung on cylinder. See if it will unscrew.

Dan
 

PoTreeBoy

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Scratch what I said. Parts diagram shows a plug and o-ring so not a banjo. Elbow looks like it might be screwed into bung on cylinder. See if it will unscrew.

Dan
I think that screw is a vent. I always thought the fittings were welded on.
 

L35

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Yea maybe I’ll mess with it tomorrow. Will report back findings whenever I do.
 

DustyRusty

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You might want to wait till Monday when the Kubota dealer is open if you need parts. Just hope that they have the parts in stock. You could call and give them the part numbers and have them check the inventory before taking it apart. I doubt that you would want to disable your tractor for a week or more just because the parts were not available at the dealer or even worse, were back-ordered. You can live with a small leak, but not a total breakdown.
 
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Nicksacco

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The cylinder has a small piece of tubing welded onto it to which the nipple is brazed. In the first pic, you can see the brass line once I moved the nipple into a 90 deg position.
Likely the nipple/hose was bumped into something.

I didn't have a torch hot enough for brazing, so I ended up removing the nipple and TIG welding on a new nipple to the existing tube. My torch got it hot enough to twist off the nipple.

The "plug" part number 070 on your diagram threads into the nipple and has an Oring that will need to be removed if you weld or braze the nipple. Yours looks like the hex is stripped out.

I simply replaced the plugs on my cylinders as I rebuilt them (plugs come with an Oring) because mine were in pretty bad shape.

Here is the situation I had - note that the nipple was pretty well eaten up.

1713001461692.png



I had a 90 deg JIC fitting - so I cut off one end and welded it to the tube on the cylinder.

1713001609544.png
 
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GreensvilleJay

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Looks like #070 is used to plug the hole as they drilled through the fitting to make the passage for the oil. Similar to 'frost plugs'. Makes it easy to make(fast),threaded is cheaper than welding on the assembly line ?
 

TheOldHokie

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Looks like #070 is used to plug the hole as they drilled through the fitting to make the passage for the oil. Similar to 'frost plugs'. Makes it easy to make(fast),threaded is cheaper than welding on the assembly line ?
Hydraulic elbow fittingss are not through drilled and that plug with oring seat adds considerably to cost to manufacture

The plug has a function and it looks very much like an ORB port plug. My wild ass guess is thats a pressure test port.

Dan
 

PoTreeBoy

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Vent for what? The fitting has a hose connected to it. If its welded in and leaking the fix gets more complicated.

Dan
Don't know. People are always wanting to know how to bleed them. Maybe a drain so you can drain the fluid before removing a hose. As Nicksacco said, they're called a plug.
 

TheOldHokie

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Don't know. People are always wanting to know how to bleed them. Maybe a drain so you can drain the fluid before removing a hose. As Nicksacco said, they're called a plug.
After a little searching pretty sure thats supposed to be a gage port. Here are a couple other examples

Dan

1000002594.png


1000002595.png
 
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L35

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The cylinder has a small piece of tubing welded onto it to which the nipple is brazed. In the first pic, you can see the brass line once I moved the nipple into a 90 deg position.
Likely the nipple/hose was bumped into something.

I didn't have a torch hot enough for brazing, so I ended up removing the nipple and TIG welding on a new nipple to the existing tube. My torch got it hot enough to twist off the nipple.

The "plug" part number 070 on your diagram threads into the nipple and has an Oring that will need to be removed if you weld or braze the nipple. Yours looks like the hex is stripped out.

I simply replaced the plugs on my cylinders as I rebuilt them (plugs come with an Oring) because mine were in pretty bad shape.

Here is the situation I had - note that the nipple was pretty well eaten up.

View attachment 126258


I had a 90 deg JIC fitting - so I cut off one end and welded it to the tube on the cylinder.

View attachment 126259
Mine is leaking from that tube that is brazed onto the 90, but the side closer to the cylinder.
 

Nicksacco

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Yeah i was hoping it was because thats easier to fix.

A welding shop should be able to fix that quite easily tbough.

My thought is that welding could loosen the brazing depending how they do it. You might be better off doing what i did.
 

TheOldHokie

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Russell King

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If it was me having the problem and no good way to fix it myself, I would take it to a hydraulic cylinder repair shop and have them repair or replace that fitting and rebuild the cylinder with new seals.

I think the heat from repairing the leak is likely to damage the seals unless you disassemble the cylinder before starting.
 
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loggin

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If it was me ha the problem and no good way to fix it myself, I would take it to a hydraulic cylinder repair shop and have them repair or replace that fitting and rebuild the cylinder with new seals.

I think the heat from repairing the leak is likely to damage the seals unless you disassemble the cylinder before starting.
I believe that port is at the closed end of the cylinder. As long as the rod is in the extended position there shouldn't be any seals in that area. My concern would be taking a torch to a closed cylinder that had oil in it.

Just my 2 cents.
 

L35

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I believe that port is at the closed end of the cylinder. As long as the rod is in the extended position there shouldn't be any seals in that area. My concern would be taking a torch to a closed cylinder that had oil in it.

Just my 2 cents.
Correct.

If I weld it I would unhook the hoses and drain the oil.