Help with broken Boom Lever access

bitseeker · Feb 12, 2022

This is regarding our Kubota L5240 HST, with cab. I am hoping that someone here has had experience with the Boom-Lever that is mounted on the Loader Valve Assembly.

I have attached a photo of the issue and an image from the parts manual for reference.

The issue is that the lever arm controlled by the Boom Lever has broken off of the pivoting lever that moves the valve up or down. I cannot imagine what would have caused the lever to break off on this machine with just over 400 hours of moderate use and no abuse.

I can weld the lever back on to the pivoting part, BUT, I have to get the pivoting part out of the assembly to weld it properly.

As noted on the photo, the roll-pin has to be driven out of the Loader Link Bracket to allow the Link Pin to be removed, freeing the Boom Lever Assembly to be removed for prep and welding the lever back on.

I have removed the right side plastic panels from inside the cab, the access panel from the outer right-rear wheel well, and the seat and access panel under the seat. There is not sufficient access to the roll pin to drive it out either from inside or from below.

My current idea is that if I can remove the Loader Link Bracket from the Control Valve Assembly, I may then have sufficient access to the roll pin to allow it to be driven out. The parts diagram shows that there are four (4) part # 40 flange bolts attaching the Loader Link Bracket to the top of the Control Valve Assembly. I can see only two (2) of those flange bolts.

Do you know where the other two (2) flange bolts that mount the Bracket to the Valve Assembly are located?

Is there a better way?

Thanks for your assistance.

----------------------------------

UPDATE 02-12-2022 17:49:
I managed to loosen and remove the twp cable mounts and remove the headed pins with hairclip cotter pins from the top of the valves.
That done, the U-shaped valve lifters can be flipped back, revealing the other two (2) flange bolts.
The Bracket then easily came off of the Valve Assembly.
The roll-pin drove out easily with the assembly mounted in a vise.
The axle was easy to drive past the broken lever's cylindrical part.
I made up a brass drift to drive the two soft-material bushings out of the cylindrical part.
The parts are cleaned-up, beveled, and ready to weld (tomorrow when I'm fresher).
Then, reinstall the bushings and see how many sequence mistakes I can avoid on re-assembly.

I hope this does not happen to anyone else and that if it does, this writeup proves usefull.

JWR · Feb 14, 2022

What does this mechanism do ? I studied the drawing and the photo and I still have no idea what it does.

bitseeker · Feb 14, 2022

Maybe this will help:

The joystick moves a cable that pushes or pulls the upper end of a "bellcrank / rocker" arm.
The bellcrank pivots on the axle and moves the forked end of the bellcrank that either pulls or pushes the top of the hydraulic boom control valve up or down.
It is similar to the rocker arms on an IC engine, except the end on the valve pushes AND pulls (no valve spring).

The upper end of the bellcrank had broken entirely off and required replacement or repair.

Does that help?

-------------

This whole mechanism was not designed for repair unless I missed some other method of access.
I cannot imagine how a dealer would have fixed this or what it would have cost.
I have watched the dealer's techs work on this tractor and have borne the results.

JWR · Feb 14, 2022

"That either pulls or pushes the top of the hydraulic boom control valve up or down." I still have no idea what for. I really do not need to know, just puzzled.

Related to the FEL joystick or loader controls in general ? Otherwise what might a hydraulic boom control valve be ?

bitseeker · Feb 14, 2022

Hi JWR,

I have little talent in explaining, and I will try again:

Related to the FEL joystick or loader controls in general?

YES to both.

That either pulls or pushes the top of the hydraulic boom control valve up or down?

This problem was only with the boom up or down function of the FEL joystick.
Moving the joystick forward or back resulted in no boom up or boom down motion.
There was no force required to move the joystick forward or back (it felt broken).
The lower end of the joystick has an enclosed cable that runs back, under the seat, to a rocker arm assembly that mounts on top of the hydraulic valve that controls the hydraulic fluid to the boom hydraulic cylinders that cause the boom to raise or lower.
The part of the rocker arm attached to the cable-end of that rocker arm had broken off.
Because of the broken arm, the joystick could not move the hydraulic valve, so the boom could not move.

If that does not get it, I will try again. Please let me know.

Cheers