L39/BT1000 backhoe boom seems weak

[BillBBB]

Hi All,

Its my first post, so please be kind

I recently acquired a new to me Kubota L39 with about 600 hours. Its been fantastic learning the machine and using it at the house for some work on the drive, leveling some spots etc. Earlier this week I garnered up enough ambition to go through the exercises of removing the loader bucket (4 in1) and backhoe so I can familiarize myself with the process. The loader was no issue (I've spent some hours with a skid before) and the backhoe came off easily enough. However when I tried to reattach the backhoe I could not lift the unit to pivot in the pins with the boom cylinder it would push an inch or so and give up. There was no apparent strain on the engine and no change in sound from the backhoe or pump. The dipperstick could tilt the hoe without issue but not enough to align the pins (the dipperstick would push the boom cylinder back in if it was extended). Needless to say it was painful to get the hoe back on an involved a pump jack, some cinderblocks, lots of fiddling with the bucket and dipperstick controls, and a fair amount of cursing.

I have the backhoe a decent workout after reattaching it and the boom controls seem to operate fine lowering and raising the boom; no signs of slowness or hesitation. I dug a small trench and used the boom to try and push on some dead trees (~3-4"), the boom is definitely weak. I read through any related posts I could find here and in other forums, but I cant seem to find anyone who has had a similar issue. Things I have checked -

• Looked for any leaks or disconnected hoses
• Extended boom, dipperstick, and bucket fully, suspended ~6" inches above the ground for 15 mins with no drop at all
• Went through procedure to eliminate any air in the system

I am fairly handy and while hydraulics are somewhat new to me I do understand the basics. Any help from the members here would be greatly appreciated. I'm not afraid to involve my local dealer, but they are slow, expensive, and I want to learn how to troubleshoot and maintain this machine myself when possible.

Many Thanks,
-Bill B

 

[Jchonline]

1. Are you sure you have the hoses hooked up properly to the tractor.
2. Have you checked your hydraulic fluid level recently? Be sure it is topped up.
3. You didn't mention the outriggers/stabilizers...you are using them to raise the BH into position correct? I don't use my other controls much at all. If you are on level ground 95% of the alignment is the outriggers.
3. You should have no issues with raising the BH once the hoses are connected. If it worked fine before you took it off, hopefully it is a very simple fix.

 

[BillBBB]

Yep, I checked all fluids before I ran the tractor (it did need about 1/2 gallon of hydraulic fluid to reach the top tick). The stabilizers are working as they should and have no issues either lifting the tractor or aligning the backhoe to the support frame. Its that once it is in the lower frame notches that the boom simply wont push and pivot the couple inches that are needed to align the pins. The dipperstick has no issue tilting the hoe but it does not have enough length to accomplish the tilt (hence my rigging above). All hoses should be correct as I did some basic digging after finally reattaching the hoe and operation seemed normal (but it was wet soft sandy soil).

 

[Jchonline]

Bent hydraulic cylinder? I am assuming no if you didn't notice anything while digging.
Can you use the bucket/stick controls to align it?

Just tossing things out. This has to be something simple.

 

[BillBBB]

Nothing appears to the eye to be bent, and the cylinder does operate, its just not very strong. I pushed on a 3" dead maple (very dead) with the boom and it would extend and offer maybe a couple hundreds pounds of force and then give up. The dipperstick had no issue pushing the same rotten tree over.

 

[fried1765]

Hi All,

Its my first post, so please be kind

I recently acquired a new to me Kubota L39 with about 600 hours. Its been fantastic learning the machine and using it at the house for some work on the drive, leveling some spots etc. Earlier this week I garnered up enough ambition to go through the exercises of removing the loader bucket (4 in1) and backhoe so I can familiarize myself with the process. The loader was no issue (I've spent some hours with a skid before) and the backhoe came off easily enough. However when I tried to reattach the backhoe I could not lift the unit to pivot in the pins with the boom cylinder it would push an inch or so and give up. There was no apparent strain on the engine and no change in sound from the backhoe or pump. The dipperstick could tilt the hoe without issue but not enough to align the pins (the dipperstick would push the boom cylinder back in if it was extended). Needless to say it was painful to get the hoe back on an involved a pump jack, some cinderblocks, lots of fiddling with the bucket and dipperstick controls, and a fair amount of cursing.

I have the backhoe a decent workout after reattaching it and the boom controls seem to operate fine lowering and raising the boom; no signs of slowness or hesitation. I dug a small trench and used the boom to try and push on some dead trees (~3-4"), the boom is definitely weak. I read through any related posts I could find here and in other forums, but I cant seem to find anyone who has had a similar issue. Things I have checked -

• Looked for any leaks or disconnected hoses
• Extended boom, dipperstick, and bucket fully, suspended ~6" inches above the ground for 15 mins with no drop at all
• Went through procedure to eliminate any air in the system

I am fairly handy and while hydraulics are somewhat new to me I do understand the basics. Any help from the members here would be greatly appreciated. I'm not afraid to involve my local dealer, but they are slow, expensive, and I want to learn how to troubleshoot and maintain this machine myself when possible.

Many Thanks,
-Bill B

Have you reviewed the detach/attach procedures in the BT1000 manual?

 

[Jchonline]

Nothing appears to the eye to be bent, and the cylinder does operate, its just not very strong. I pushed on a 3" dead maple (very dead) with the boom and it would extend and offer maybe a couple hundreds pounds of force and then give up. The dipperstick had no issue pushing the same rotten tree over.

Ah so the boom cylinder is weak. How is the swing? Does it seem fast enough at RPM?

 

[Smokeydog]

With my M59 there are two valves below the seat that have to be operated switching from 3pt hitch to backhoe. Are they fully open?

 

[BillBBB]

Have you reviewed the detach/attach procedures in the BT1000 manual?

I don't have a BT1000 manual, but I have a BH92 manual and I have watched several videos regarding the process, and I do believe I am approaching the reattach process correctly. If someone has a BT1000 manual and wants to scan me the section I would be happy to try the process exactly as described!

Ah so the boom cylinder is weak. How is the swing? Does it seem fast enough at RPM?

With my M59 there are two valves below the seat that have to be operated switching from 3pt hitch to backhoe. Are they fully open?

Swing seems fine, and both under seat levers are in the correct/fully open position. Approaching PTO speed the hoe operates faster than I can smoothly manage the controls

With the hoe attached to the tractor and with the bucket down I would expect the boom should be able to lift the back of the tractor, or at least budge it. The dipperstick will, but the boom wont.

 

[NormL]

I don't have a BT1000 manual, but I have a BH92 manual and I have watched several videos regarding the process, and I do believe I am approaching the reattach process correctly. If someone has a BT1000 manual and wants to scan me the section I would be happy to try the process exactly as described!



Swing seems fine, and both under seat levers are in the correct/fully open position. Approaching PTO speed the hoe operates faster than I can smoothly manage the controls

With the hoe attached to the tractor and with the bucket down I would expect the boom should be able to lift the back of the tractor, or at least budge it. The dipperstick will, but the boom wont.

I'm not an hydraulics authority by any means but have you tried reversing the away and back function to determine if the problem is in the spool valve? If nothing changes the cylinder may have issues. Just my 2 cents!!