BX23S Shims = More Pressure - Better/Worse?

[Mark_BX25D]

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

Can you clarify that last comment? Does this mean your gauge is off?

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

That's excellent info! Thanks!

 

[leveraddict]

Kubit ......This is not a correct pressure reading iif it is taken correctly at the loader valve! You can not lead people to believe they can raise or its ok to raise pressues to 3060 psi!

 

[lugbolt]

I see and hear this all the time. My bx ain't got enough power. So they start shimming because somebody on some website said they needed to so it must be right, and second during a web search they find some company sells a whole kit with a set of destructions and a sales pitch that says that every bx owner needs it. next complaint is "the engine feels weaker than it used to I need u to check it out". It takes X amount of engine power to run the hydraulic pump at rated (factory-set) hyd pressure. It takes more power to run the same pump at higher than factory specified pressure thus the engine feels weaker.

can't say how many hydraulic problems I'd seen in the years I did dealer work, on bx's, with cranked hydraulic pressure. As a dealer tech we were required to do certain things (liability, dealer agreements, etc) and one of those was that if we did a hydraulic repair, particularly warranty repairs, we had to document the hydrualic pressure. On warranty claims if it wasn't documented we didn't get paid and the owner got the bill. So there were two options. Lie about it, which I saw some of, or do the right thing and check it, document it. Some of them were cranked up well beyond factory spec. Warranty kicked those back instantly and we had to call customer & get them to pay, OR option #2, reduce the pressure back to spec and document it that way. I usually just removed the shims and pulled it back to the upper end of the spec. Saw a few of them where they didn't know what they were doing and they shimmed the relief at or just above idle speed, then when the engine was at rated speed the pressure was higher'n a cat's back, busted hoses, and bent cylinder rods were not uncommon. Warranty wont' cover those if the pump pressure is higher than expected. On ones that were obviously tampered with--it takes time to adjust the pressure back to spec, and time=money in a technician's life. That meant warranty don't pay for it, so there was a choice that the owner had to make. One, let warranty pay for the hydraulic repair and the owner pay for the readjustment of the relief, or two let the owner pay for it all. Or the obvious, three, tell him to come get it & charge him for the diagnosis time, and then he can take it to some shade tree that thinks he knows what he's doing.

 

[BX23S-1]

Adjust as necessary to OEM spec, and leave it the hell alone.
My rule of thumb, if i need more power, i buy a bigger tractor.

 

[Henro]

Adjust as necessary to OEM spec, and leave it the hell alone.
My rule of thumb, if i need more power, i buy a bigger tractor.

Good advice, but apparently the OP bought the tractor new and did not adjust anything himself.

My head is spinning now trying to digest what has been stated. I THINK the OP says he had his gage accuracy verified.

It is not clear where he is taking the pressure measurement.

It makes no sense that the hydraulic pump supplying the cylinders would reach the same pressure level as the HST pump. The PRV on that pump should prevent it.

Granted a PRV could fail and become stuck closed.

Personally I would not operate that tractor until I determined if my reading was wrong, or if correct, what the cause was for the extremely out of spec pressure.

 

[Kubit]

Earlier, I posted this on another forum that, after finishing a large yard project (for me, anyway) I would split the loader from the tractor & post the result--here it is:

'Late finish, 18” down & about 18” shy of where I needed to be for the last tree ball this poor boy arrived at the rock from hell. Anyway, I wanted to get this settled, so split loader & took a reading from the recommended fitting and, of course, gauge showed 1800 psi (hash marks are in 50’s & skinny spaced so +/- the usual).

Still don’t understand the 2700 psi reading from the 3rd function valve, but as I stated earlier, unit has been going strong for 135 hours. Based on Dave’s remarks glad I upped the hose psi to 4000. I do notice that when the BH bucket & the thumb are run independently they move faster than when they are run simultaneously—possibly could the pressure be split or shared at that point which is why I haven’t had any issues?

Thanks again all for your comments & sharing your knowledge.'

 

[Crash277]

Earlier, I posted this on another forum that, after finishing a large yard project (for me, anyway) I would split the loader from the tractor & post the result--here it is:

'Late finish, 18” down & about 18” shy of where I needed to be for the last tree ball this poor boy arrived at the rock from hell. Anyway, I wanted to get this settled, so split loader & took a reading from the recommended fitting and, of course, gauge showed 1800 psi (hash marks are in 50’s & skinny spaced so +/- the usual).

Still don’t understand the 2700 psi reading from the 3rd function valve, but as I stated earlier, unit has been going strong for 135 hours. Based on Dave’s remarks glad I upped the hose psi to 4000. I do notice that when the BH bucket & the thumb are run independently they move faster than when they are run simultaneously—possibly could the pressure be split or shared at that point which is why I haven’t had any issues?

Thanks again all for your comments & sharing your knowledge.'

flow rate. You only have 6.2gpm (on a 23s) so doing multiple things will slow your movements. For example, if I lower both outriggers at the same time, they are slower than just running 1 at a time.

 

[leveraddict]

Glad to see you got the correct pressure reading! Directions do come in handy now and then!

 

[BX23S-1]

flow rate. You only have 6.2gpm (on a 23s) so doing multiple things will slow your movements. For example, if I lower both outriggers at the same time, they are slower than just running 1 at a time.

BINGO!

 

[Henro]

Still don’t understand the 2700 psi reading from the 3rd function valve, but as I stated earlier, unit has been going strong for 135 hours.

This is the question remaining in my mind as well.

Whitetiger stated that the HST and Hydraulic pumps are separate systems, as also indicated by the drawing that was posted the other thread about this issue (I assume, as I remember it but do not see it in this thread). Have to look for that other thread now...

You took that reading in a static condition with nothing external pushing on any of the hydraulic cylinders, right? With the guage that you now know is accurate?

Any chance to could take the same measurement at the same point again, to verify it still reads the same high value?

Edit: Post #6 in the following link shows the hydraulic schematic, for anyone who remains interested.

HYDRO PRESSURE HIGH BX23S

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...

www.orangetractortalks.com

 

[Kubit]

This is the question remaining in my mind as well.

Whitetiger stated that the HST and Hydraulic pumps are separate systems, as also indicated by the drawing that was posted the other thread about this issue (I assume, as I remember it but do not see it in this thread). Have to look for that other thread now...

You took that reading in a static condition with nothing external pushing on any of the hydraulic cylinders, right? With the guage that you now know is accurate?

Any chance to could take the same measurement at the same point again, to verify it still reads the same high value?

Edit: Post #6 in the following link shows the hydraulic schematic, for anyone who remains interested.

HYDRO PRESSURE HIGH BX23S

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...

www.orangetractortalks.com

Henro,
Been off grid for a while but sure, will retest from the 3rd funtion valve & post the results tomorrow.
To answer your question: Yes, the 2700 psi reading was a static test reading--normal engine temp, all attachments idle, engine rpm at high idle. The joy stick was moved & its handle button depressed to activate the 3F valve circuit. I split the coupling on the hose leading from the 3F valve to the thumb cylinder & that is where I read 2700 psi.

 

[Kubit]

Henro,
Been off grid for a while but sure, will retest from the 3rd funtion valve & post the results tomorrow.
To answer your question: Yes, the 2700 psi reading was a static test reading--normal engine temp, all attachments idle, engine rpm at high idle. The joy stick was moved & its handle button depressed to activate the 3F valve circuit. I split the coupling on the hose leading from the 3F valve to the thumb cylinder & that is where I read 2700 psi.

Did that pressure check from the 3F valve & of course, gauge read tad over 1800 psi—same as from FEL manifold. One caveat though: I’m about done for the season with the backhoe so that was removed & replaced with the 3PH & ballast box. I had forgotten that when I got the 2700 psi reading it was on the return line from the thumb cylinder back to the 3F valve and I should have done the same prior to removing the BH so that all tests were equal--could that have increased the pressure?

 

[Henro]

Did that pressure check from the 3F valve & of course, gauge read tad over 1800 psi—same as from FEL manifold. One caveat though: I’m about done for the season with the backhoe so that was removed & replaced with the 3PH & ballast box. I had forgotten that when I got the 2700 psi reading it was on the return line from the thumb cylinder back to the 3F valve and I should have done the same prior to removing the BH so that all tests were equal--could that have increased the pressure?

Thanks for taking the time to do that measurement again.

Is there a chance the bucket was pushing against the thumb when you took the first measurement? If so, high pressure in a line from the thumb cylinder back to the 3F valve could have been the result. Without knowing what the hydraulic circuit looks like, I would still be inclined to bet this is what happened.

scenario: Thumb cylinder is closed off hydraulically by the 3F valve. Bucket pushes on the thumb. Pressure increases in one of the lines connected to the thumb cylinder. Pressure goes high in that one line, due to the mechanical advantage of the bucket linkage. Bucket holds its position when control lever is centered. Pressure in that one line remains high.

IF you were hooked up in a way to measure the high pressure in that one thumb cylinder line, you would see high pressure on your gage.

This MIGHT be what happened.

 

[Kubit]

Thanks for taking the time to do that measurement again.

Is there a chance the bucket was pushing against the thumb when you took the first measurement? If so, high pressure in a line from the thumb cylinder back to the 3F valve could have been the result. Without knowing what the hydraulic circuit looks like, I would still be inclined to bet this is what happened.

scenario: Thumb cylinder is closed off hydraulically by the 3F valve. Bucket pushes on the thumb. Pressure increases in one of the lines connected to the thumb cylinder. Pressure goes high in that one line, due to the mechanical advantage of the bucket linkage. Bucket holds its position when control lever is centered. Pressure in that one line remains high.

IF you were hooked up in a way to measure the high pressure in that one thumb cylinder line, you would see high pressure on your gage.

This MIGHT be what happened.

Good thought but bucket was open & its lever was not in play. Only the thumb 3F lever was operated & thumb would be stationary since its circuit was dead ended at the pressure gauge. Though, I was not looking at the thumb but focused on the gauge looking forward. Could that be the answer?

 

[Henro]

Good thought but bucket was open & its lever was not in play. Only the thumb 3F lever was operated & thumb would be stationary since its circuit was dead ended at the pressure gauge. Though, I was not looking at the thumb but focused on the gauge looking forward. Could that be the answer?

Looks like this will go down as another of life's unanswered mysteries! LOL...

 

[Kubit]

"Looks like this will go down as another of life's unanswered mysteries! LOL..."

Yep, whole lot of those going around these days.