Loader self-leveling works going up, but not down

[HarleyMonster]

I have a year old L47 with just over 400 hours on it and I am having a problem with the loader痴 self-leveling function. After adjustment the bucket or forks stay level as they should going up, but there is no compensation when moving in the down direction. If I start with the forks level at max height they are nearly vertical when they reach the ground. Kubota says no negative angle is acceptable.

I have the Workshop Manual, there is an adjustment for raising and another adjustment for lowering. I have adjusted the up motion so the forks are staying perfectly level as the boom goes up; however, no matter how I adjust the lower leveling adjustment there is no change. I have screwed the lowering adjustment all the way in and all the way out and either way the forks do not compensate at all and are almost vertical by the time the boom is all the way down.

The factory specs are 0 to 4 degrees rollback going up and 2 to 6 degrees going down. No down or negative angle is acceptable.

I believe the problem is in the controller.

I had the self-leveling problem before I did the 400 hour service when all fluids and filters were changed, changed with all Kubota filters and Kubota Super UTD2. Both the up and down would not stay level before the service, I was able to adjust the up, but not the down.

Does anyone have any ideas?

 

[oldnslo]

Does the manual have a hydraulic schematic for the self level feature? If yes can you post this?

For lowering you should be diverting a portion of the return oil from the lift cylinders to the tilt circuit. Sounds like something in this circuit had failed.

 

[HarleyMonster]

Does the manual have a hydraulic schematic for the self level feature? If yes can you post this?

For lowering you should be diverting a portion of the return oil from the lift cylinders to the tilt circuit. Sounds like something in this circuit had failed.

Thank you for your reply oldnslo.

Yes, there is a flow diagram for every operation of the controller and the system works just as you describe.

What I am going to check next is there is a lever on the front of the joystick control; lever down = self-leveling; lever up = normal operation. I had the thought this lever may not be fully engaging, I will check that out then post again.

 

[HarleyMonster]

Solution found: The lever switch used to engage loader self-leveling control uses a push/pull cable down to the loader control valve, it is the center cable of three. I loosened the bulkhead nuts on the cable and let it take a relaxed position while the switch was in the self-leveling position then tightened the nuts in that neutral push/pull position. The cable had been set so the self-leveling spool was not able to engage fully.

When testing it was the first time since I have owned the tractor, since new, the down self-leveling was working, then it was just a matter of trial and error adjustments to get forks to stay within factory specs. Now I have about 2 degrees of roll back during lifting and lowering. The forks will now be a joy to use.

I hope this helps someone else.

 

[oldnslo]

Harley,
Glad the solution was that simple and thanks for posting this for future reference.

 

[flingwing1969]

Solution found: The lever switch used to engage loader self-leveling control uses a push/pull cable down to the loader control valve, it is the center cable of three. I loosened the bulkhead nuts on the cable and let it take a relaxed position while the switch was in the self-leveling position then tightened the nuts in that neutral push/pull position. The cable had been set so the self-leveling spool was not able to engage fully.

When testing it was the first time since I have owned the tractor, since new, the down self-leveling was working, then it was just a matter of trial and error adjustments to get forks to stay within factory specs. Now I have about 2 degrees of roll back during lifting and lowering. The forks will now be a joy to use.

I hope this helps someone else.

Thanks good information.