kubota L5740 loader bucket problem

   / kubota L5740 loader bucket problem #1  

bucktaker

Platinum Member
Joined
Apr 20, 2010
Messages
909
Location
Sw Ohio
Tractor
Kubota L5740
Recently my loader is not holding the bucket position. I find the bucket fully dumped within a few hrs of shutting it down. Lift and curl feel fine when operating and i can see no leaks on the cylinders or hoses or connections. Fluid is correct level and no contaminants

I am thinking there must be an internal seal leaking??? ideas

l5740 Hst-1 2008 275 hrs


thanks Larry
 
   / kubota L5740 loader bucket problem #2  
Perhaps someone else can come on and answer this but if you put a mechanic's stethoscope on a cylinder could you hear fluid moving past a seal?
 
   / kubota L5740 loader bucket problem #3  
Option 1: The internal seals are shot & the external seal is leaking air but not oil. Fluid moves from the rod end to the but end & air gets in. As the rod end would be pressurized a bit I'm not clear how this would happen. You'd be experiencing floppy bucket due to air in the cylinders.

Option 2: Your control valve is worn & leaking. If you disconnect the QDs on the bucket lines & the problem stops, this is the root cause. The only fix is replacing the whole valve.

I've gone through 6? 7? Rear remotes on my L4060 under warranty & only 1 of the 3 actually hold my TnT cylinders for any length of time. Same basic symptoms & diagnostics as #2. Kubota front spools are usually pretty good though.
 
   / kubota L5740 loader bucket problem
  • Thread Starter
#4  
Option 1: The internal seals are shot & the external seal is leaking air but not oil. Fluid moves from the rod end to the but end & air gets in. As the rod end would be pressurized a bit I'm not clear how this would happen. You'd be experiencing floppy bucket due to air in the cylinders.

Option 2: Your control valve is worn & leaking. If you disconnect the QDs on the bucket lines & the problem stops, this is the root cause. The only fix is replacing the whole valve.

I've gone through 6? 7? Rear remotes on my L4060 under warranty & only 1 of the 3 actually hold my TnT cylinders for any length of time. Same basic symptoms & diagnostics as #2. Kubota front spools are usually pretty good though.

Thanks Fallon
I disconnected the loader from the valve and the bucket still drops indicating the bucket cylinders are the problem the arms remained up . Guess I will remove the cylinders and have them tested off the tractor
 
   / kubota L5740 loader bucket problem #5  
Its prob time to rebuild both of them. After all they have the same amount of strokes on them.
 
   / kubota L5740 loader bucket problem #6  
Before replacing seals, best to go through this simple test procedure in case your cylinders are beyond repair because the CYLINDER TUBE(S) BEING SWELLED out.

Dave M7040
 

Attachments

  • Testing double acting cylinders.pdf
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