Kubota BX25 FEL falls under own weight

[LD1]

Cylinders won't drift (in compression) due to faulty seals in the cylinder

 

[LD1]

Just for clarity....we ARE talking about lift cylinders right? Not the curl cylinders?

 

[dubojr10]

dubo,
A leaking load check would typically cause a different issue than what you are reporting.

I suspect a failing cylinder seal is your problem. Do you have a jack that you can put under the loader bucket?
If yes raise the jack fully.
Place the jack under the bucket.
Lower the bucket onto the jack and shut the tractor engine off.
Move the joystick like you are trying the lower the bucket to relieve the pressure in the circuit.

Follow the hydraulic hose from the cap (lift) end of the cylinder back to the quick disconnect and uncouple only this quick disconnect.

Lower that jack and watch to see if the loader drifts down. If it drifts down you have a bad seal on one of the lift cylinders.

if no movement, your valve is leaking.

You will have to lift the bucket slightly with the jack to reconnect the hose.

Just for clarity....we ARE talking about lift cylinders right? Not the curl cylinders?

I pressure tested the quick connect lines after removing the FEL completely. The pressure issue was still present. That would eliminate the possibility of the lift cylinders leaking right?

 

[oldnslo]

Cylinders won't drift (in compression) due to faulty seals in the cylinder

LD1,
with only the lift hose disconnected the oil could leak past the piston seals and through the valve allowing the fuel to drift down. I am not sure on loader valves if the spool overlap is the same for the blind end cylinder port as it is for the rod end cylinder port. Seems like the frequency of fixing the cylinder seals slows or stops the drift would suggest the dual leak paths through the valve increase the drift to point of being unacceptable.

 

[oldnslo]

I pressure tested the quick connect lines after removing the FEL completely. The pressure issue was still present. That would eliminate the possibility of the lift cylinders leaking right?

Dubo,
With such a small oil volume I would expect the gauge to drop to zero very quickly when centering the valve spool.

 

[dubojr10]

Dubo,
With such a small oil volume I would expect the gauge to drop to zero very quickly when centering the valve spool.

Ok so after the information received today (thanks guys!) I did some more checking. I checked the pressures and pressure drop on all four connection to the FEL. All appear to act the same going up and down.

I set up the jack as suggested and tested as you outlined. The bucket does appear to drop when you release the jack. One additional note is if you start the tractor while the lift connection is still disconnected and use the lever to move the FEL bucket down... it actually goes up slowly, not down. Is that also an indication of a cylinder issue?

With these actions and tests, are we thinking a cylinder leak now? Is there a way to test them individually too?

Again thanks for everyone's help!

 

[K5lwq]

One additional note is if you start the tractor while the lift connection is still disconnected and use the lever to move the FEL bucket down... it actually goes up slowly, not down. Is that also an indication of a cylinder issue?

With these actions and tests, are we thinking a cylinder leak now? Is there a way to test them individually too?

Again thanks for everyone's help!

I agree with oldnslo, you have a cylinder seal bypassing causing your problem. With the lift side disconnected and capped, when you try to retract the cylinder nothing should happen if seals are good. However, because there is more surface area on the extend side, the cylinder will actually extend when trying to retract because of faulty seal. To test each cylinder separately you would have to cap off one at a time and send power to one at a time.

 

[dubojr10]

I agree with oldnslo, you have a cylinder seal bypassing causing your problem. With the lift side disconnected and capped, when you try to retract the cylinder nothing should happen if seals are good. However, because there is more surface area on the extend side, the cylinder will actually extend when trying to retract because of faulty seal. To test each cylinder separately you would have to cap off one at a time and send power to one at a time.

So should I just rebuild both or have them rebuilt locally? Seal kits are about $70 each from Messick's. Seems expensive for such small cylinders..

 

[K5lwq]

So should I just rebuild both or have them rebuilt locally? Seal kits are about $70 each from Messick's. Seems expensive for such small cylinders..

I would call and find out what a local shop would charge. They can do it much faster and have proper tools. Sometimes they will have the seal kits in stock as well.

 

[dubojr10]

I would call and find out what a local shop would charge. They can do it much faster and have proper tools. Sometimes they will have the seal kits in stock as well.

Understood. Thanks