Hydraulic pressure bump up options

skeets

Well-known member

Equipment
BX 2360 /B2601
Oct 2, 2009
14,617
3,449
113
SW Pa
Common guys, he is just giving ya information, and everybody wants something more,, more HP in the street rod or bike, or boat for that matter,, And y'all know what happens, things go well for a time,, and then not so much. Its you call, hop it up and then spend beau coupe bucks fixing it up,,,, so ya live with it
Speaking for my self, if I want/need more out of my machine I will buy. rent, borrow a machine to do what I need.... I spent too many nights picking parts off the ground after soupin things up and they go sideways.. just sayin
 
Last edited:
  • Like
Reactions: 3 users

WI_Hedgehog

Well-known member

Equipment
BX2370 (impliment details in Profile-About)
Apr 24, 2024
359
376
63
Milwaukee, Wisconsin, U.S.A.
I've not heard anyone look at the size of the pump and then offer an opinion regarding output pressure. I'm no expert, but when I saw the size of pump on the BX...to me it seems Kubota looked at the tractor footprint, figured the maximum safe lifting capacity, and sized the pump to that. The BX pump is tiny, I can understand shimming an old pump back into spec, but shimming a pump over-spec looks like more than the pump can handle.
I have NO IDEA why people assume these kits are all about boosting your pressure ABOVE factory specs.. we have NEVER promoted that! The point of the kit is to make sure you get the maximum performance that your machine is DESIGNED for... most machines are never adjusted/checked at the dealer before delivery.. additionally over time the spring in the hydraulic pump weakens and adjustments are part of the maintenance.. not sure why some people don't understand this.
I think because your first post promotes that. "25% MORE POWER" cannot realistically be interpreted as tractors are typically under-pressured by 25%, if I remember correctly without shims (just the spring) the tractor won't be 25% under even with a reasonably weak spring.

The engineering limits for a hydraulic system are 20% under to 10% over ideal system pressure, beyond either extreme is likely to be inefficient and cause problems such as premature failure. Because "ideal" isn't an exact number, rather a calculated expected value, "ideal" is different depending on the job being performed, temperature, and other factors, so tractors should be set to factory specifications so they're as efficient as practical under varying conditions.

In the video you posted (which if I remember is Brock from Rock Hill Farms) the targeted pressure is 10% over factory spec, so right at the limit of "not good." +10% is usually thought of as "the upper limit of safe"--this should not be a goal! It's like driving as fast as you can along the edge of a cliff, ignoring the possibility of something unforseen happening. Or being diabetic and drinking a 2L of soda daily because you've been doing it for 40 years and are still alive.

I suggest before anyone "JailBreak" (which literally means to make the unit do something it's not supposed to) they look at the pump--just look at it, it's pretty small for what it is expected to do. Do you really want to work that pump harder every time you hit a cylinder limit raising an implement? Do you really want to heat a hydraulic system beyond design by lifting heavier loads with the Front End Loader when that design is so stretched already it requires UDT2 to dissipate the OEM calculated heat and still lubricate properly? That's a risky game, like using cheaper hydraulic oil...
 
  • Like
Reactions: 2 users

NCL4701

Well-known member

Equipment
L4701, T2290, WC68, grapple, BB1572, Farmi W50R, Howes 500, 16kW IMD gen, WG24
Apr 27, 2020
2,824
4,304
113
Central Piedmont, NC
I found the videos and discussion interesting. I’ve seen numerous posts scattered about here where folks mention shimming the valve to increase pressure, usually moving to the top of mfg specs but not over. So for a dummy such as myself, it was cool to see it’s just some rounds punched out of shim stock inserted into a highly accessible valve body with a bit of math to determine what thickness change is needed to achieve a desired result.

While I did learn some stuff, the loader on my L is well matched to the tractor (pretty much the loader will lift what the tractor will hold whilst reasonably ballasted) so I’m not a customer. Aside from Sumo springs and 10 ply mud tires my truck is bone stock, and the only mod to my Mule is a winch installed with a factory mount/wiring kit so maybe I’m just not a big fan of performance mods. (Often is an exercise in moving the failure point from one place to another.) I like the failure points on my tractor being it runs out of lift, torque, or traction before busting something expensive. Of course YMMV.

Thanks for the videos, though.

Edit: I’m aware this comment doesn’t fully make sense now. The thread it was originally in included a video of a gentleman demonstrating adding shims to the relief valve on an L01 series tractor.
 
Last edited:
  • Like
Reactions: 2 users

mikester

Well-known member

Equipment
M59 TLB
Oct 21, 2017
3,602
2,087
113
Canada
www.divergentstuff.ca
Use common sense in all things.
What a lot of guys who look at your photos think is that their SCUT/CUTs will suddenly be able to handle big loads that their lightweight compact machines weren't designed to handle.

Construction equipment is usually advertised with the rated loads at 50% tipping weight because there are safety and liability concerns dealing with commercial buyers who demand higher factors of safety and OSHA requirements.

SCUTs/CUTs are advertised with their max lift capacity because they are sold to homeowner and farm duty class buyers. Equipment sold here has lower factors of safety because purchasers are more price and bragging rights sensitive consumers.

The CUT/SCUT hydraulics are designed for 2,500psi and not the 10,000psi shock loads they see when you lift at max capacity and hit a bump or bounce your load.
 
  • Like
Reactions: 1 user

BAP

Well-known member
Lifetime Member

Equipment
2012 Kubota 2920, 60MMM, FEL, BH65 48" Bush Hog, 60"Backblade, B2782B Snowblower
Dec 31, 2012
2,787
898
113
New Hampshire
We use genuine Kubota shims and a higher quality gauge, full color detailed instructions and a customer support number...you get what you pay for..
So you are copying the bxexpanded kit and selling it claiming that you have a novel new idea.
 

TheOldHokie

Well-known member
Lifetime Member

Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
8,931
4,672
113
Myersville, MD
windyridgefarm.us
I've not heard anyone look at the size of the pump and then offer an opinion regarding output pressure. I'm no expert, but when I saw the size of pump on the BX...to me it seems Kubota looked at the tractor footprint, figured the maximum safe lifting capacity, and sized the pump to that. The BX pump is tiny, I can understand shimming an old pump back into spec, but shimming a pump over-spec looks like more than the pump can handle.

I think because your first post promotes that. "25% MORE POWER" cannot realistically be interpreted as tractors are typically under-pressured by 25%, if I remember correctly without shims (just the spring) the tractor won't be 25% under even with a reasonably weak spring.

The engineering limits for a hydraulic system are 20% under to 10% over ideal system pressure, beyond either extreme is likely to be inefficient and cause problems such as premature failure. Because "ideal" isn't an exact number, rather a calculated expected value, "ideal" is different depending on the job being performed, temperature, and other factors, so tractors should be set to factory specifications so they're as efficient as practical under varying conditions.

In the video you posted (which if I remember is Brock from Rock Hill Farms) the targeted pressure is 10% over factory spec, so right at the limit of "not good." +10% is usually thought of as "the upper limit of safe"--this should not be a goal! It's like driving as fast as you can along the edge of a cliff, ignoring the possibility of something unforseen happening. Or being diabetic and drinking a 2L of soda daily because you've been doing it for 40 years and are still alive.

I suggest before anyone "JailBreak" (which literally means to make the unit do something it's not supposed to) they look at the pump--just look at it, it's pretty small for what it is expected to do. Do you really want to work that pump harder every time you hit a cylinder limit raising an implement? Do you really want to heat a hydraulic system beyond design by lifting heavier loads with the Front End Loader when that design is so stretched already it requires UDT2 to dissipate the OEM calculated heat and still lubricate properly? That's a risky game, like using cheaper hydraulic oil...
If you study gear pumps what you will find is smaller pumps are generally capable of much higher working pressure than larger ones. Thats the simple physics of pressure times cross sectional area of the gears and case Aluminum gear pumps in the size used on a BX are typically good to 3600 PSI or more.

I would worry more about the increased forces on the tractor, loader, backhoe, and associated plumbing.

Dan
 
  • Like
Reactions: 2 users

John T

Well-known member

Equipment
2017 BX23S
May 5, 2017
863
343
63
under a rock
I've been running 2000 psi on my BX for a couple years... not a problem.

PS, the lifting capacity STILL sucks... :ROFLMAO::ROFLMAO::LOL:
 
  • Haha
Reactions: 1 users

mcmxi

Well-known member
Lifetime Member

Equipment
***Current*** M6060HDC, MX6000HSTC & GL7000 ***Sold*** MX6000HST & BX25DLB
Feb 9, 2021
5,390
6,470
113
NW Montana
I've been running 2000 psi on my BX for a couple years... not a problem.

PS, the lifting capacity STILL sucks... :ROFLMAO::ROFLMAO::LOL:
What's the factory pressure range for the BX? I'm genuinely interested so not trying to cause trouble.

How does the casual tractor user interpret @Mrlunchbox's statement that Kubota sells shim kits, and the fact that kits are available from non-Kubota sources which make some dramatic claims re lift capacity? Is the thought process that the former makes the latter seem reasonable or acceptable? Most successful scams work because there appear to be reasonable or plausible benefits for little in the way of input. Surely Kubota doesn't intend for customers to raise the pressure above the factory specs, and don't sell shim kits for that reason.

I've never had an interest in getting more lift capacity with any of the four Kubotas I've owned but it's good to have a discussion for those that are interested. This forum is a good resource for many so it's a positive that we can talk about this and perhaps provide clarity so that others can make a well thought out and reasoned choice rather than defer to the sales pitch of those whose only intent is to make money.

There are plenty of snake oil merchants out there in every walk of life, just look at the supplement industry for example, and they have no interest or concern about the physical, emotional or financial welfare of the customer. For me, this is where a well-engineered product shines. It's my opinion that Kubota looks out for the customer and they feel responsible and accountable, and are interested in a lifelong relationship and customer loyalty. They make mistakes just like everyone else, but overall they have honorable intentions. If you know anything about the Japanese culture you'll be aware of their honor-based approach to just about every aspect of life.
 
Last edited:
  • Like
Reactions: 1 users

TheOldHokie

Well-known member
Lifetime Member

Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
8,931
4,672
113
Myersville, MD
windyridgefarm.us
What's the factory pressure range for the BX? I'm genuinely interested so not trying to cause trouble.

How does the casual tractor user interpret @Mrlunchbox's statement that Kubota sells shim kits, and the fact that kits are available from non-Kubota sources which make some dramatic claims re lift capacity? Is the thought process that the former makes the latter seem reasonable or acceptable? Most successful scams work because there appear to be reasonable or plausible benefits for little in the way of input. Surely Kubota doesn't intend for customers to raise the pressure above the factory specs, and don't sell shim kits for that reason.

I've never had an interest in getting more lift capacity with any of the four Kubotas I've owned but it's good to have a discussion for those that are interested. This forum is a good resource for many so it's a positive that we can talk about this and perhaps provide clarity so that others can make a well thought out and reasoned choice rather than defer to the sales pitch of those whose only intent is to make money.

There are plenty of snake oil merchants out there in every walk of life, just look at the supplement industry for example, and they have no interest or concern about the physical, emotional or financial welfare of the customer. For me, this is where a well-engineered product shines. It's my opinion that Kubota looks out for the customer and they feel responsible and accountable, and are interested in a lifelong relationship and customer loyalty. They make mistakes just like everyone else, but overall they have honorable intentions. If you know anything about the Japanese culture you'll be aware of their honor-based approach to just about every aspect of life.
Its not complicated.

Kubota publishes the hydraulic pressure specifications they think are appropriate for the equipment they engineered.

Kubota sells adjusting shims so you can adjust the relief setting to match those specifications as parts age or get replaced and the factory settings are lost.

Exceeding the Kubota hydraulic pressure specifications is just like increasing the max governed speed, bolting on a turbo, or milling a head to increase power. Kubota is going to tell you to pound sand if something subsequently fails even if your modifications were not the cause. That strikes me as a perfectly reasonable policy.

Dan
 
  • Like
Reactions: 1 user

mcmxi

Well-known member
Lifetime Member

Equipment
***Current*** M6060HDC, MX6000HSTC & GL7000 ***Sold*** MX6000HST & BX25DLB
Feb 9, 2021
5,390
6,470
113
NW Montana
Its not complicated.

Kubota publishes the hydraulic pressure specifications they think are appropriate for the equipment they engineered.

Kubota sells adjusting shims so you can adjust the relief setting to match those specifications as parts age or get replaced and the factory settings are lost.

Exceeding the Kubota hydraulic pressure specifications is just like increasing the max governed speed, bolting on a turbo, or milling a head to increase power. Kubota is going to tell you to pound sand if something subsequently fails even if your modifications were not the cause. That strikes me as a perfectly reasonable policy.

Dan
These are the points I've been trying to illustrate with my questions to which I already knew the answers, as well as Neil's video. Some will be swayed by the misdirection though, and perhaps this thread will help in that regard. A soft approach where people get to use their own brains to navigate the maze is often better than telling someone how or why it is.
 
  • Like
Reactions: 1 users

John T

Well-known member

Equipment
2017 BX23S
May 5, 2017
863
343
63
under a rock
What's the factory pressure range for the BX? .
I believe it's 1850 psi
But a lot (NOT ALL) come from the factory around 1700psi

THAT is why they sell the shims to bring it up if you need/choose to.
also over time it may decrease for various reasons.

All this drama about blown lines and death and destruction is quite hilarious.

The hoses/lines will handle 3000 psi.
so 2000psi even 2500 is FINE.

again, common sense is mandatory when operating any equipment.

when I bought my tractor I could not pick up a pallet half full of firewood......
now at 2000 psi, I move firewood pallets all the time.... usually a foot off the ground.... point A to point B
 
  • Love
  • Like
Reactions: 1 users

TheOldHokie

Well-known member
Lifetime Member

Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
8,931
4,672
113
Myersville, MD
windyridgefarm.us
I believe it's 1850 psi
But a lot (NOT ALL) come from the factory around 1700psi

THAT is why they sell the shims to bring it up if you need/choose to.
also over time it may decrease for various reasons.

All this drama about blown lines and death and destruction is quite hilarious.

The hoses/lines will handle 3000 psi.
so 2000psi even 2500 is FINE.

again, common sense is mandatory when operating any equipment.

when I bought my tractor I could not pick up a pallet half full of firewood......
now at 2000 psi, I move firewood pallets all the time.... usually a foot off the ground.... point A to point B
Hydraulic working pressure is based on a 4:1 safety factor. Those 3000 PSI hoses have a burst presure of 12,000 PSI. Frankly I woukd have guessed the hoses were 5000 PSI.

Dam
 
  • Like
Reactions: 1 user

mcmxi

Well-known member
Lifetime Member

Equipment
***Current*** M6060HDC, MX6000HSTC & GL7000 ***Sold*** MX6000HST & BX25DLB
Feb 9, 2021
5,390
6,470
113
NW Montana
I believe it's 1850 psi
But a lot (NOT ALL) come from the factory around 1700psi
So "a lot" are delivered with pressure within 10% of the factory upper limit ... so how do we get to 25% more lift capacity with less than a 10% increase in pressure. This is the whole point of every post I've made. Using shims to get the pressure to the max factory setting is one thing, but selling snake oil upgrades such as claiming 25% more lift capacity without any downside seems to be misleading at best.

Using the argument that Kubota sells shims without stating why they sell them, and using that to imply that aftermarket shim kits with claims of this or that are consistent with Kubota's approach is disingenuous in my opinion.
 
  • Like
Reactions: 2 users

John T

Well-known member

Equipment
2017 BX23S
May 5, 2017
863
343
63
under a rock
So "a lot" are delivered with pressure within 10% of the factory upper limit ... so how do we get to 25% more lift capacity with less than a 10% increase in pressure. This is the whole point of every post I've made. Using shims to get the pressure to the max factory setting is one thing, but selling snake oil upgrades such as claiming 25% more lift capacity without any downside seems to be misleading at best.

Using the argument that Kubota sells shims without stating why they sell them, and using that to imply that aftermarket shim kits with claims of this or that are consistent with Kubota's approach is disingenuous in my opinion.
exactly.

Same thing goes for the guy that sells bigger "upgraded" loader cylinders....

his big claim is you get (so many more inches) higher lift....

OK, big deal.... I've asked multiple times, How much more weight can you lift??

CRICKETS...

higher lift only puts you in more danger.

it's all horse crap. a few shims boosting the pressure conservatively is one thing.... and can be helpful.

But their are no free lunches..
if you really need that much more, buy a bigger tractor.
 
  • Like
Reactions: 3 users

MapleLeafFarmer

Well-known member

Equipment
Lots incl. B and L kubotas
Dec 2, 2019
658
535
93
E.
my two cents is no different than so much other gear-head related stuff:

- adding more lights to ROP's to get more light
- adding bigger tires to atv
- adding fuel/oil/crank case additive for better lubricity/performance/cleaning, etc...
- removing cat. convertors for lower operating temps on gas engines
- after market exhausts that flow better and give more hp
- carbon fiber wheels for my truck to lighten unsprung weight
- freer flowing air filter kits to help engine breath better
- wheel spacer to improve stability
- filled tires to add more ground pressure and lower c.g.
- etc.... could go on forever.

people have been making mod's on their stuff since ..... forever. Does it make a measurable difference to anything but a persons own private beliefs and pocket book???? IDK.

Some maybe good choices, some maybe not depending on situation etc.... but heck to each their own not going to push my values on others. Have at it... turbo your 25hp tractor versus just spending less and buying a factory designed and warranted 33hp tractor.... freedom of choice a good thing IMHO.

Why does it elicit so much passion and excitement though is what gives me entertainment.

cheers folks and happy holidays
 
  • Like
Reactions: 2 users

lugbolt

Well-known member

Equipment
ZG127S-54
Oct 15, 2015
5,246
1,927
113
Mid, South, USA
a lot of DIY'ers don't know how to check the pressure properly anyway, nor do they have a decent enough gauge set to do it with. Also increasing the shim stack to get more pressure is often a band aid for a failing pump, pump drive, plugged/restricted suction side, etc. That's why I don't give advice on how to do increase it. Once you see how quickly a pin hole in a hose can take the hide right off of your elbow or whatever (think: water jet), cause gangrene, whatever...you start to think about that stuff.
 
  • Like
Reactions: 3 users

WI_Hedgehog

Well-known member

Equipment
BX2370 (impliment details in Profile-About)
Apr 24, 2024
359
376
63
Milwaukee, Wisconsin, U.S.A.
If you study gear pumps what you will find is smaller pumps are generally capable of much higher working pressure than larger ones. Thats the simple physics of pressure times cross sectional area of the gears and case Aluminum gear pumps in the size used on a BX are typically good to 3600 PSI or more.

I would worry more about the increased forces on the tractor, loader, backhoe, and associated plumbing.

Dan
That's a great point, as resistant to learning "one more subject" as I've been, hydraulics should be one I learn. I'm looking into taking a course on the subject because tribal knowledge is relatively hard to get--and more to the point I'm slow to understand it.

...the guy that sells bigger "upgraded" loader cylinders....I've asked multiple times, How much more weight can you lift??

CRICKETS...
Calculated is 35% more weight, doing the math on videos of guys who tried it is 32%, so the cylinders do lift about as much additional as can reasonably be done I guess. If I remember correctly the guy claims 30% on his site, so he's honest about it.

With bucket hooks and chains the lift height for less than maximum weight loads would be useful to me, I'm waiting until getting a grapple to see if in my case the aftermarket cylinders would help. I seem to remember the guy saying to not lift full weight loads to full height because doing so is not safe.

Forgive my using "I" so much, I'm camped out in the woods on a phone with weak signal so have to rely on memory, plus don't want to imply my thoughts apply to everyone's situation or usage.
20241129_082711.jpg
 
Last edited:

John T

Well-known member

Equipment
2017 BX23S
May 5, 2017
863
343
63
under a rock
Calculated is 35% more weight, doing the math on videos of guys who tried it is 32%, so the cylinders do lift about as much additional as can reasonably done I guess. If I remember correctly the guy claims 30% on his site, so he's honest about it.
OK, I stand corrected...

It's been a few years and when they first came out there was no mention of weight increase.
I think he was in the "beta" testing stage.

The are a little pricey.... almost $1000 shipped with 2 extended hoses.

but 32% on a LA340 loader is another 240LB. Nothing to sneeze at.....

35% would be 262lb increase....
 
  • Like
Reactions: 1 user