BX23S Shims = More Pressure - Better/Worse?

[whitetiger]

Not to steer this thread off course, but....
how is it that when you use the joystick while turning the steering wheel, the steering wheel locks up.

Your hydraulic oil goes from the pump, through the Priority valve which supplies the steering circuit fully, then sends the rest to the loader and 3 point valves. If the loader valve operation is affecting your steering, there is a malfunction in the Priority valve.

Neither the loader nor the 3 point operation should ever have any effect on the steering.

 

[NHSleddog]

I did the math. I set mine at 1850psi (fully warmed up) and i`m not going to go above the factory spec. There is no need to be above the factory spec of 1850psi for such a small tractor....

That is great for you. Reread my first sentence. Yours is at spec., not under. Apparently there are also many others that are out of spec, or over time fall out of spec. There is nothing wrong with them turning it back up, Kubota actually provides a kit to do it.

And maybe a 100-200lb difference would be make believe or not real to some people, but it is still real regardless of ones beliefs. A person saying there is no effect when it is measurable and reproducable would be closer to the placebo affect. When a guy can't lift the front wheels off the ground with the loader (pre-install) and he can easily lift it off the ground after the tractor is brought back up to spec is a difference; rather people want to call it that or not. It is not make believe, not magic. Literally turn it up 1lb and there will be a measurable difference. Seat of the pants measurable? Probably not, but measurable none the less.

I don't own a BX so it doesn't affect me either way. I was just saying there is nothing wrong with a guy turning his BX up to SPEC (why there is a spec and kit to adjust it). No need to fear the future tractor killing boogeyman for turning/running your machine up to spec. Kubota does it all the time.

 

[BX23S-1]

Your hydraulic oil goes from the pump, through the Priority valve which supplies the steering circuit fully, then sends the rest to the loader and 3 point valves. If the loader valve operation is affecting your steering, there is a malfunction in the Priority valve.

Neither the loader nor the 3 point operation should ever have any effect on the steering.

If you have access to a 2017 BX23s, go try it and then get back to me. I`ve drove a couple other different 2017 BX23s`s just to see if this was normal (because i had doubts that it was normal), and they all did it. Maybe i`m not describing it clear enough for you to understand what i`m saying(?)

If you`re operating the joystick, the steering locks up. Mine has done it since day one brand new. This is just me, personally, but i think this is very dangerous having your steering locking up, at ANY speed.

If you try a newer BX than my 2017 BX23s, maybe the newer ones have been revised and you might not ever see or find what i`m describing here.

Maybe go try this... run your tractor in figure 8 circles while running the joystick. Move the joystick while you`re trying to steer the tractor left to right, right to left. Let me know what you find out.

 

[BX23S-1]

That is great for you. Reread my first sentence. Yours is at spec., not under. Apparently there are also many others that are out of spec, or over time fall out of spec. There is nothing wrong with them turning it back up, Kubota actually provides a kit to do it.

And maybe a 100-200lb difference would be make believe or not real to some people, but it is still real regardless of ones beliefs. A person saying there is no effect when it is measurable and reproducable would be closer to the placebo affect. When a guy can't lift the front wheels off the ground with the loader (pre-install) and he can easily lift it off the ground after the tractor is brought back up to spec is a difference; rather people want to call it that or not. It is not make believe, not magic. Literally turn it up 1lb and there will be a measurable difference. Seat of the pants measurable? Probably not, but measurable none the less.

I don't own a BX so it doesn't affect me either way. I was just saying there is nothing wrong with a guy turning his BX up to SPEC (why there is a spec and kit to adjust it). No need to fear the future tractor killing boogeyman for turning/running your machine up to spec. Kubota does it all the time.

I understood you. Mine was just under spec a little before i brought it up to OEM spec with the shim kit. I dont care what others do to theirs. My only point was people making it sound like this shimming ordeal was a great big godful event, and its not. But we all know how people like to exaggerate and inflate things.

 

[PaulR]

Sooooo, THIS is how they do it. I was wondering. My guy at the dealership asked me about the lift capacity when I brought it back for the quick-connect install. He asked me "how do you like the lift capacity? Is it doing ok?" I was like yea, full bucket of gravel, good size pallet of stones. he was like "good, I set the pressures and most people are happy, no complaints, but if so let me know and I can raise the pressures higher"...........I kinda looked at him with a blank face after he mentioned that.

 

[Michigankubota]

 

[BX23S-1]

Sooooo, THIS is how they do it. I was wondering. My guy at the dealership asked me about the lift capacity when I brought it back for the quick-connect install. He asked me "how do you like the lift capacity? Is it doing ok?" I was like yea, full bucket of gravel, good size pallet of stones. he was like "good, I set the pressures and most people are happy, no complaints, but if so let me know and I can raise the pressures higher"...........I kinda looked at him with a blank face after he mentioned that.

As long as you have it documented "in writing" that "THEY" did it and not YOU. It will be easier to explain to kubota corp if there is a problem.

 

[Kubit]

High PSI Reading:

My BX23S is a 2019 with 135 hours. I had ordered it with what Kubota calls a 3rd function valve and the mechanical thumb options. I converted the thumb to hydraulic & use that valve to power the thumb cylinder. I began reading forum posts regarding PSI & ordered the BXpanded gauge kit. Tested today & I’m getting a 2700 PSI reading at high idle connected to the output from the 3rd function valve—it was a lot simpler to connect there rather than the recommended output to the loader.

I would understand that overall hydro pressure should be constant through-out the system & should never get a “boost” regardless of where it was connected--or am I understanding wrong?

Machine has been running flawless—no leaks or operating issues.
Thanks for any input here.

PS: Other than my mod to the thumb all hydraulics are Kubota original issue.

 

[Henro]

High PSI Reading:

My BX23S is a 2019 with 135 hours. I had ordered it with what Kubota calls a 3rd function valve and the mechanical thumb options. I converted the thumb to hydraulic & use that valve to power the thumb cylinder. I began reading forum posts regarding PSI & ordered the BXpanded gauge kit. Tested today & I’m getting a 2700 PSI reading at high idle connected to the output from the 3rd function valve—it was a lot simpler to connect there rather than the recommended output to the loader.

I would understand that overall hydro pressure should be constant through-out the system & should never get a “boost” regardless of where it was connected--or am I understanding wrong?

Machine has been running flawless—no leaks or operating issues.
Thanks for any input here.

PS: Other than my mod to the thumb all hydraulics are Kubota original issue.

You might want to post this question in a new thread as buried this deep in this one it might not catch a lot of attention.

I would question the gauge you are using. It could be defective. That is a huge increase over the rated 1850 psi for the BX that has been mentioned previously in this thread.

Another thought might be, could the gauge face be marked in a confusing way? Enough that you might be reading it wrong? Just a thought and I do not mean to question your eyesight or anything else...

 

[DustyRusty]

I want to see a picture of the hydraulic thumb, along with more details about the installation, etc.. As for the pressures, the gauge is most likely faulty. Just like taking blood pressure, you should follow the instructions and take it in the proper place. Otherwise, you might get a false reading, and be treating non existent problems.

 

[Kubit]

You might want to post this question in a new thread as buried this deep in this one it might not catch a lot of attention.

I would question the gauge you are using. It could be defective. That is a huge increase over the rated 1850 psi for the BX that has been mentioned previously in this thread.

Another thought might be, could the gauge face be marked in a confusing way? Enough that you might be reading it wrong? Just a thought and I do not mean to question your eyesight or anything else...

Thanks for the tip, I'll repost as suggested & no offense taken re. eyesight Gauge is new from BXpanded & noted there as "Class ASME Class A" accuracy--but as they say: trust everybody BUT cut the cards.

 

[Kubit]

I want to see a picture of the hydraulic thumb, along with more details about the installation, etc.. As for the pressures, the gauge is most likely faulty. Just like taking blood pressure, you should follow the instructions and take it in the proper place. Otherwise, you might get a false reading, and be treating non existent problems.

I had just replied a few minutes ago to another posting asking almost the same question so here it is:


I run the thumb cylinder by simply reaching the control stick to my left & a bit behind while in the backhoe seat. I have it connected so that the bucket & the thumb controls are moved in the same functional direction so there is no confusion. That is both in "out" position to open & both in "in" position to close--picture your arms in front of you opening & closing. Works pretty smooth, strong grip & of course, no getting off & on tractor.

The cylinder I used was Surplus Center 9-8771-12

Photos:
#1 Connections @ 3F Valve
#2 Connections @ Loader to Tractor Rear
#3 Connections @ Tractor Rear to Backhoe
#4 *Connection @ Top of Cylinder. Note Cross Tube Cut & Welded Parallel to Hydro Fittings. All cylinders that I found had the cross tube perpendicular to the hydro fittings & that would have put the hydro lines in an un-neat route & had them stretched when dipperstick was moved--it could be made to work but I preferrred the route I took.
#5 *Connection @ Bottom of Cylinder
*Note Spacers Required to “center” Cylinder in Thumb

Hope this helps
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Last edited

 

[Kubit]

PS: Forgot (it's been a year). Pic #4: At top of cylinder I added 3/4" THK x 3/4" H x 2 3/4" L spacer. This to increase OAL of cylinder to maximum travel both ways so to accommodate mechanical travel limitations of thumb min/max.

 

[Mark_BX25D]

I would question the gauge you are using. It could be defective. That is a huge increase over the rated 1850 psi for the BX that has been mentioned previously in this thread.

I agree fully with double checking that gauge, but on the other hand.... Hydraulic systems are rarely recommended to operate at the max safe pressure. Manufacturers are a cautious bunch, due to fear of lawsuits.

Case in point: When buying a log splitter years ago I researched their tonnage ratings thoroughly. What I found is that almost all manufacturers state their tonnage at the max safe operating pressure, but run them far lower. Most common log splitters are rated at 3500 psi, but actually run at 2250 or 2500. That's quite a de-rating!

And we should all recognize that if the components are RATED to run 3500, they will actually run safely at more than that. Why? Because the compmonent manufacturers are a cautious bunch, too. They want a safety margin between their test data and their publicly stated ratings.

I did find one by Speeco that actually runs at its rated pressure of 3500, so the tonnage I actually get is the tonnage I was sold. Imagine that! And yes, it's been running at that pressure for about 15 years of heavy usage, so I think it's pretty safe.

So again, while I agree with double-checking that pressure, it really would not surprise me.

 

[Henro]

I agree fully with double checking that gauge, but on the other hand.... Hydraulic systems are rarely recommended to operate at the max safe pressure. Manufacturers are a cautious bunch, due to fear of lawsuits.

Case in point: When buying a log splitter years ago I researched their tonnage ratings thoroughly. What I found is that almost all manufacturers state their tonnage at the max safe operating pressure, but run them far lower. Most common log splitters are rated at 3500 psi, but actually run at 2250 or 2500. That's quite a de-rating!

And we should all recognize that if the components are RATED to run 3500, they will actually run safely at more than that. Why? Because the compmonent manufacturers are a cautious bunch, too. They want a safety margin between their test data and their publicly stated ratings.

I did find one by Speeco that actually runs at its rated pressure of 3500, so the tonnage I actually get is the tonnage I was sold. Imagine that! And yes, it's been running at that pressure for about 15 years of heavy usage, so I think it's pretty safe.

So again, while I agree with double-checking that pressure, it really would not surprise me.

it sounds like the OP purchased the tractor new, so it’s unlikely the shims on the pressure relief valve were changed by anybody without his knowledge. Had the tractor been purchased used, then I agree there’s no telling what anybody might’ve done in the past.

While anything is possible, my guess would be it to be highly unlikely for a Kubota tractor to come new with the hydraulic pressure that much out of spec. But nothing is impossible!

My money is on the gauge being faulty…

 

[Kubit]

I agree fully with double checking that gauge, but on the other hand.... Hydraulic systems are rarely recommended to operate at the max safe pressure. Manufacturers are a cautious bunch, due to fear of lawsuits.

Case in point: When buying a log splitter years ago I researched their tonnage ratings thoroughly. What I found is that almost all manufacturers state their tonnage at the max safe operating pressure, but run them far lower. Most common log splitters are rated at 3500 psi, but actually run at 2250 or 2500. That's quite a de-rating!

And we should all recognize that if the components are RATED to run 3500, they will actually run safely at more than that. Why? Because the compmonent manufacturers are a cautious bunch, too. They want a safety margin between their test data and their publicly stated ratings.

I did find one by Speeco that actually runs at its rated pressure of 3500, so the tonnage I actually get is the tonnage I was sold. Imagine that! And yes, it's been running at that pressure for about 15 years of heavy usage, so I think it's pretty safe.

So again, while I agree with double-checking that pressure, it really would not surprise me.

Well, along your line of thought, all of the factory lines are rated 3000 psi and the new lines I added from the 3F valve to the thumb cylinder are rated 4000 psi.

 

[Henro]

Well, along your line of thought, all of the factory lines are rated 3000 psi and the new lines I added from the 3F valve to the thumb cylinder are rated 4000 psi.

But what about internal components? The parts of the pumps themselves and whatever else is in there?

There is likely a reason Kubota specs hydraulic pressure at 1850 PSI, or whatever it may be for a BX. Just because a hose is rated for a certain pressure does not mean the entire system can safely operate at the pressure a hose is rated at.

Myself, I would be concerned if my system was operating at over 40 percent plus of rated pressure.

Kubit, I do not mean to say you are implying it is OK, you may be saying the same thing I just tried to say a different way...or the opposite. It was not clear to me...still think the OP better first verify the accuracy of his pressure gauge...

 

[Kubit]

But what about internal components? The parts of the pumps themselves and whatever else is in there?

There is likely a reason Kubota specs hydraulic pressure at 1850 PSI, or whatever it may be for a BX. Just because a hose is rated for a certain pressure does not mean the entire system can safely operate at the pressure a hose is rated at.

Myself, I would be concerned if my system was operating at over 40 percent plus of rated pressure.

Kubit, I do not mean to say you are implying it is OK, you may be saying the same thing I just tried to say a different way...or the opposite. It was not clear to me...still think the OP better first verify the accuracy of his pressure gauge...

Yes, verify is my intent--planning on stopping at local hydro shop tomorrow to have it tested & if defective will replace. Note though, it is a new BXpanded gauge kit first time used & in order for it to carry its rating ( Class ASME Class A ) it would have had to be tested prior to sale.

Strange, if gauge is accurate, been operating for 135 hours with no issues.

I'll post the forum with the results--along with Kubota if gauge is proven accurate.

Meantime, thanks all for your replies.

 

[Mark_BX25D]

But what about internal components? The parts of the pumps themselves and whatever else is in there?

There is likely a reason Kubota specs hydraulic pressure at 1850 PSI, or whatever it may be for a BX. Just because a hose is rated for a certain pressure does not mean the entire system can safely operate at the pressure a hose is rated at.

Exactly. You have to know the weakest link, and allow a safety margin for that component.

 

[Kubit]

Turns out:
--Okay to take readings from the bypass valve
--Gauge is correct
--PSI ratings here are incorrect

Shout out: THANKS DAVE!

BX23S Workshop Manual WSM Section 7, Page 3 shows 3060 psi maximum: