I have a 2018 Branson 3520h with a grapple with hydraulic cylinders on each side. The right cylinder started closing on its own when I would open the grapple. Now I can't even open the right cylinder. The left one works fine. Both cylinders are operated by a diverter valve. There are not any leaks anywhere. Anyone have any idea where I should start diagnosing?
Grapple hydraulic issue
- Thread starter Crash0473
- Start date
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IndyJay
Veteran Member
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- Apr 23, 2021
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- S.E. Indiana
- Tractor
- 2021 Kioti DK4510MS w/Loader, Grapple Prev: Massey 1250
Crash, are you able to pull the right grapple open by hand with the tractor not running?
IndyJay
Veteran Member
- Joined
- Apr 23, 2021
- Messages
- 1,425
- Location
- S.E. Indiana
- Tractor
- 2021 Kioti DK4510MS w/Loader, Grapple Prev: Massey 1250
You might check with folks on the "Hydraulics" forum subgroup. They may have some suggestions for best next steps.
oldnslo
Super Member
I presume this is a two lid grapple where there is a cylinder for each lid since you state one opens one doesn’t.
Does left build full pressure and clamp solidly and stay clamped or does it just close and clamp weakly? Do you hear the relief kick in when cylinders hit end of travel?
From what you have described I suspect left is weak on clamp pressure and will not hold solidly. If this is true suspect seals are damaged on right cylinder.
To test this you would have to isolate the left cylinder from the right to see if left now holds solidly.
Does left build full pressure and clamp solidly and stay clamped or does it just close and clamp weakly? Do you hear the relief kick in when cylinders hit end of travel?
From what you have described I suspect left is weak on clamp pressure and will not hold solidly. If this is true suspect seals are damaged on right cylinder.
To test this you would have to isolate the left cylinder from the right to see if left now holds solidly.
I'll have to check tomorrow. I can open it by hand with the tractor running but it then wants to close the left one.
When I try to open both clamps the right stays shut.. I can Open the right by hand with the tractor running but it then wants to close the left one.
oldnslo
Super Member
I suspect you would get same results with the engine off since you are manually forcing oil from right cylinder to left cylinder.
MechanicalGuy
Platinum Member
First step is to show a picture of what type of grapple that you are running. It makes all the difference in the world if you have dual lids or not, and what orientation the cylinders are in.
a cylinder will do the opposite direction commanded if the piston seal exhibits enough leakage when the command is to compress the cylinder. Fluid leaks by the piston seal and since the piston end has more area than the rod end, the pressure will overcome the intended direction of travel-if the piston seal leaks enough.
pics.
a cylinder will do the opposite direction commanded if the piston seal exhibits enough leakage when the command is to compress the cylinder. Fluid leaks by the piston seal and since the piston end has more area than the rod end, the pressure will overcome the intended direction of travel-if the piston seal leaks enough.
pics.
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