Hydraulic Failure

[Harold B]

BX23S was operating normally when parked after garden turnover, soft till just a three inch turnover of fluff, nothing difficult. Upon starting two days later, tractor has lost all hydro, nothing works. There was a strange ringing noise, the fan was turning. Hydraulic fluid full so I changed the filter and topped off fluid, no help. Split the old filter, some clutch material but no metal. Removed floor pan, removed driveshaft, input shaft good and coupling good. I can turn the input shaft on HST by hand and I feel some resistance and hear a consistent clicking noise.

 

[John T]

You changed the filter but did you clean the hydraulic screen??

 

[Harold B]

No filter screen… it’s a screw on filter.

 

[Harold B]

Did not know it existed! I will open that goose tomorrow. Thank you!

 

[PoTreeBoy]

Does the 3pt lift work? Power steering? Loader? I assume the backhoe is off.

 

[North Idaho Wolfman]

Bet you have a hydraulic line (quick connect that isn't seated) issue.
#1 is the BH connection on the back of the tractor.
Oh and by the way the HST has nothing to do with the hydraulics, completely separate pump.

And yes it has a filter screen:


And if you have steering, three point, loader /BH operation but, you have and drive issue.
Check the range level first.
Then check the parking brake.

 

[whitetiger]

I can turn the input shaft on HST by hand and I feel some resistance and hear a consistent clicking noise.

Well, that's not good!
You should not be able to turn it easily by hand.

 

[Harold B]

Does the 3pt lift work? Power steering? Loader? I assume the backhoe is off.

No

 

[Harold B]

Bet you have a hydraulic line (quick connect that isn't seated) issue.
#1 is the BH connection on the back of the tractor.
Oh and by the way the HST has nothing to do with the hydraulics, completely separate pump.

And yes it has a filter screen:
View attachment 180250

And if you have steering, three point, loader /BH operation but, you have and drive issue.
Check the range level first.
Then check the parking brake.

Complete power failure, reseated all quick connections on this mornings list, thank you.

 

[Harold B]

Well, that's not good!
You should not be able to turn it easily by hand.

I have a video can’t seem to post it, I’m kinda a big guy, but none the less it turns rather easily in both directions and makes a low pitched click, similar to spring loaded gears riding on their edges barely engaging, moved hydro levers around and nothing changes.

 

[Harold B]

The fact that you lost all hydraulic drive at once, along with the ringing noise, makes me wonder if something failed internally in the HST or if the pump is no longer getting driven properly. Since you’ve already checked the driveshaft and coupling, I’d probably start by checking the HST charge pressure and making sure the suction side isn’t restricted or letting air in. A full reservoir doesn’t necessarily mean the pump is getting oil.

The clutch material in the filter is also worth investigating, although it’s hard to say whether that’s related without knowing how much was there. I wouldn’t run it much more until you’ve narrowed it down, as you don’t want to turn a smaller problem into a major repair. The clicking when turning the input shaft by hand is interesting, too. Does the engine still sound normal when you start it, and does the tractor move at all in either forward or reverse?

No complete hydraulic loss, I haven’t previously split one of the used filters open, but while changing them, since new, there has always some fine black material, looks like clutch material, pouring the fluid from the old split filter thru a paint funnel strainer generated enough to smear across my index finger with no “sparkles”, also picked up no metal with a pen magnet either. Currently, disassembled did not check charge pressure before but will dig into suction screen, since I’m this far. Thank you

 

[PoTreeBoy]

Does the 3pt lift work? Power steering? Loader? I assume the backhoe is off.

There's a WorkShop Manual available at KubotaBooks. The hydraulic diagram is shown below

If you've lost travel, steer, loader, and backhoe, the parts they have in common are
• Fluid level
• Screen/ filter
• Hydraulic pump
• Relief valve
• Priority valve
My first suspect would be relief valve. The WSM should tell you where these items are.

 

[Harold B]

Morning update: all attachments are off, BH circuit quick connection bypass hose firmly in place, pulled lower suction screen, it’s clean and clear, dumped all hydraulic fluid thru a 300 oil mesh with three magnetic rings below mesh strainer, no metal in mesh caught above and no debris. The black particles are finer than 300 micron so I’m almost certain it’s just normal clutch wear. Also, I failed to mention tractor has 250.3 hours and these are not abused hours with a tighter service regiment than what is suggested, because I have another tractor that is used significantly more and requires more attention and I just do both at the same time. PM’s are super fine, but I’m not interested in buying stuff that’s free. IE: workshop,or service manuals and I have more tools than I can keep up with. Heading to the local Kubota dealer (Siler Implement) for next suggested adventure.

 

[TheOldHokie]

Morning update: all attachments are off, BH circuit quick connection bypass hose firmly in place, pulled lower suction screen, it’s clean and clear, dumped all hydraulic fluid thru a 300 oil mesh with three magnetic rings below mesh strainer, no metal in mesh caught above and no debris. The black particles are finer than 300 micron so I’m almost certain it’s just normal clutch wear. Also, I failed to mention tractor has 250.3 hours and these are not abused hours with a tighter service regiment than what is suggested, because I have another tractor that is used significantly more and requires more attention and I just do both at the same time. PM’s are super fine, but I’m not interested in buying stuff that’s free. IE: workshop,or service manuals and I have more tools than I can keep up with. Heading to the local Kubota dealer (Siler Implement) for next suggested adventure.

Have you checked the obvious - output at the hydraulic pump? Its really easy on that tractor.

Dan

 

[PoTreeBoy]

Have you checked the obvious - output at the hydraulic pump? Its really easy on that tractor.

Dan

View attachment 180269

Yeppers.
OP, the fluid should come out at 140. You'll have to remove or get through the quick disconnect couplings to a catch bucket or back into the fill port.

 

[TheOldHokie]

Yeppers.
OP, the fluid should come out at 140. You'll have to remove or get through the quick disconnect couplings to a catch bucket or back into the fill port.

I would just remove the male QC from the hose (150) and stick the hose in the filler. Start tractor and use your eyeballs

Dan

 

[North Idaho Wolfman]

If it's lost all functios with the HST and Hydraulics, my bet is on this connection having an issue:

 

[Harold B]

So… after a long winded discussion with the senior tech at Siler Implement. He is convinced the input pump shaft is sheared at or very near the cylinder block assembly. The clicking noise is most likely the spines riding over each other at the break. The shaft should be somewhat difficult to turn (not by hand). The shaft when turned should not make any noise louder than the bearings moving and one could hear the cylinder block pistons move with ear on the cover. Biggest kick in the pants is the powertrain warranty expired in June 2026!

 

[Harold B]

The manual has the whole transaxle out and turn up making the cover horizontal. Anyone ever tried to remove the cover vertical still in the tractor? Just to maybe get a better look.

 

[Harold B]

Also reached out to Kubota as the tractor only has 250.3 hours on it.