I have this machine and the blade wont hold the weight of the machine up at all..I have replaced the spool valve in the main control valve and all O-rings and springs..Blade is still doing same thing..use it ro raise machine and it just drops back down wont support the weight..had cylinder checked..its good..Could it be leaking back through the Rotary Joint letting the fliud get pushed back into the system from there?
Kubota KX161-3ST Blade Issues
- Thread starter TFordALA
- Start date
Since you are not getting any immediate help...
Can you remove the lines from the control valve and plug them?
If so, you could use the boom to lift the front of the excavator, lower the blade, block off the lines feeding the blade cylinder that go through the rotary joint, and then lower the excavator onto the blade, and watch what happens. If it still leaks down, this would isolate the issue to something after the control valve. OR if it holds the excavator up, it would point to something going on in the control valve possibly.
Was the cylinder checked by someone who you have faith in? There was another thread here with the same problem, and the guy used the same procedure outlined above to determine his cylinder was good, by taking off a line at the cylinder, and plugging the cylinder and line end. His issue ended up being an o ring in the control valve.
Divide and conquer approach to finding the problem.
Can you remove the lines from the control valve and plug them?
If so, you could use the boom to lift the front of the excavator, lower the blade, block off the lines feeding the blade cylinder that go through the rotary joint, and then lower the excavator onto the blade, and watch what happens. If it still leaks down, this would isolate the issue to something after the control valve. OR if it holds the excavator up, it would point to something going on in the control valve possibly.
Was the cylinder checked by someone who you have faith in? There was another thread here with the same problem, and the guy used the same procedure outlined above to determine his cylinder was good, by taking off a line at the cylinder, and plugging the cylinder and line end. His issue ended up being an o ring in the control valve.
Divide and conquer approach to finding the problem.
RCW
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Equipment
BX2360, FEL, MMM, BX2750D snowblower. 1953 Minneapolis Moline ZAU
Trust me, I don't pretend to understand hydraulics well, especially excavators....
Are you sure the cylinder is good? You said it was checked.....
If that were a tractor and the valve was repaired/working, all that would remain to leak down in the circuit would be the cylinder.
My thought should be taken with a grain of salt, just trying to help.
Are you sure the cylinder is good? You said it was checked.....
If that were a tractor and the valve was repaired/working, all that would remain to leak down in the circuit would be the cylinder.
My thought should be taken with a grain of salt, just trying to help.
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Was there discussion about using a pilot operated check valve block on the cylinder in that thread? Might be an option. Not sure how easy it is go access the rotary joint if needed, and if everything else works properly, the easy way out may be the most reasonable...I actually may be thinking of a different thread somewhere, as I remember the guy wanting to use a float function with the blade...
I remember you said in that other thread that the cylinder held for a couple hours when you did the test, so in my mind that is a pretty conclusive determination that it is not leaking internally.