L3901 Loader Failure

[AllenBC]

OK

 

[AllenBC]

Now things were more controlled. Oil came out of the hose with coupler and arms rose. Unfortunately, I don't know whether they rose for the test with the naked open valve port - I was so concerned about the geyser that I didn't notice.

 

[AllenBC]

I wish I had a hose with a fitting I could screw into the naked port to watch it over a longer time.

 

[TheOldHokie]

Now things were more controlled. Oil came out of the hose with coupler and arms rose. Unfortunately, I don't know whether they rose for the test with the naked open valve port - I was so concerned about the geyser that I didn't notice.

Understood and thats my fault. I sĥould have anticipated the back pressure

I am sure the loader rose on first test. What we now know is loader valve is sending oil to cylinder and couplers are working on both supply and return side.

Since return oil is supposed to go out power beyond, through down stream valves, and back to tank what is preventing it?

Dan

 

[AllenBC]

I did the test with the male connector back in. This time fluid came out of the hose with the female coupler removed. The bucket also raised. Unfortunately, I don't know whether it raised when the test was done with the naked spool valve port - I was distracted by the oil gusher.

 

[TheOldHokie]

I wish I had a hose with a fitting I could screw into the naked port to watch it over a longer time.

I dont think we would learn anything. The valve and couplers are working correctly. The power beyond port appears to be blocked yet you say the backhoe works. You hsd the valve dissasembled, cleaned and inspected so apparrently nothing in the valve. Thats bizarre. Ready to take it anther step?

 

[AllenBC]

Sorry for the double answers. After posting I did not see my first answer so assumed it went to bit purgatory and answered again.

 

[AllenBC]

Sure, ready for another step. Hope it doesn't give me a hydraulic oil shower but am so frustrated I will risk even that !!

 

[TheOldHokie]

Sorry for the double answers. After posting I did not see my first answer so assumed it went to bit purgatory and answered again.

The beauty of in petson conversation.

Read me last comment.

Dan

 

[AllenBC]

Do remember that the raise bucket function was working more or less. It is the down function that fubar.
Allen

 

[TheOldHokie]

Sure, ready for another step. Hope it doesn't give me a hydraulic oil shower but am so frustrated I will risk even that !!

OK - here is the analysis.

The valve and couplers are working all the way up to the return port. The loader wont raise when that port is connectec so it must be blocked somewhere. You say backhoe works which seems impossible. Next step would be disconnect lo power beyond hose and reroute straight to tank. What do you have in the way of extra hose and fittings?

Dan

 

[TheOldHokie]

Do remember that the raise bucket function was working more or less. It is the down function that fubar.
Allen

What is more or less? I thought it would not raise?

 

[AllenBC]

No. It's the down function that no go. I think I posted that in the beginning. Recently pushing the joystick forward which should lower the bucket instead raises it. That didn't happen at first but is happening now.

Now do I do the same test but with the yellow labeled quick connects?

 

[TheOldHokie]

No. It's the down function that no go. I think I posted that in the beginning. Recently pushing the joystick forward which should lower the bucket instead raises it. That didn't happen at first but is happening now.

Now do I do the same test but with the yellow labeled quick connects?

Is the raise function working normally.? Not slow or weak?

 

[AllenBC]

Sometimes the raise function had been weak - jerky even. I can go reconnect the female fitting and see how the raise function is doing. Because the only way to lower is with the float and that pretty rough, I had not been testing the raise function much recently.

 

[AllenBC]

BTW, I have been setting the torque to 30 pound feet for the male quick disconnects. Does that sound about right? I know too much torque can damage the mating surfaces and too little causes leaks.

 

[TheOldHokie]

Sometimes the raise function had been weak - jerky even. I can go reconnect the female fitting and see how the raise function is doing. Because the only way to lower is with the float and that pretty rough, I had not been testing the raise function much recently.

I will bet that if you curl at the same time as lower it works normally and stops once curl gets to full back.

Dan

 

[AllenBC]

That I have to test. Will be back with results in a few

 

[AllenBC]

BINGO!!!
So smooth!
Unfortunately, that's not a movement I would ordinarily do when using the tractor for work.
What does it mean??

 

[TheOldHokie]

BINGO!!!
So smooth!
Unfortunately, that's not a movement I would ordinarily do when using the tractor for work.
What does it mean??

Ir means power beyond is blocked. Kubota loader valves are not notmsl animals. The boom spool is serial and exhsust oil is not sent to tank. Ot is sent to neutral (power beyond) whee it passesxthrough the bucket spool and out the power beyond port. The bucket spool is a parallel spool and if the bucket spool is moved to curl that neutral oil gets diverted to the bucket cylinder and the return from the bucket is sent to tank. No obstruction and both cylinders move in lock step.

Dan