BX24 Increased pressure with shims

[310-510]

I finally managed to test the pressure and found my BX24 had 1740 PSI at WOT and warm fluid. I added 4mm shim and the pressure went to 1900 PSI at WOT. WOW, what a difference. I have a tractor that can lift a full bucket, a backhoe that can really scratch the dirt, and I can get by running at 2500 - 2600 RPM for most work. The most noticeable lift is with the front bucket forks. The BX will now lift a 440 pound 5' flail mower on a pallet when before the modification, it would not even curl the weight. Just to be clear, it won't lift the flail mower very high and it won't lift the flail mower very fast, but all I needed to do was be able to lift the flail mower to move it in and out of my trailer.

OK, now that I think adding pressure is the holy grail of making my BX great, what component will I be breaking or shortening the life of?

 

[radman1]

I wouldn't be too concerned. The increase in pressure was only about 10%. Just be careful about lifting too much and making the back end too light. At 10%, bending or breaking something is not likely. Increased pump wear is not a real factor.

 

[Matt_Jr]

That's awesome. I've never had problems lifting with mine though. It's lifted anything that would fit in the bucket. However forks do lesson lifting capacity. My guess on what could end up having problems in the future is nothing with that small of an increase. These lil' 'botas are tough. Keep an eye where the arms attach and frequently check for metal for fatigue/cracks on the loader arms and don't let any thing down fast and stop the lowering of the bucket too suddenly. My guess is you'll be alright.

 

[GreenWannabe]

Does the BX24 manual give maximum operating pressure? The specs on the website don't.

 

[310-510]

Does the BX24 manual give maximum operating pressure? The specs on the website don't.

The Kubota dealer here in Omaha indicated that everything in the hydraulic system was rated at 2000 psi or greater. How true that statement is, I don't know.

 

[AndyinIowa]

I wouldn't be so quick to dismiss a pressure increase as harmless to the system. Some of our tractors use gear pumps for aux. hydraulics.


Aluminum gear pumps undergo a 'cut-in' at the factory. They are run at a pressure close to the shipping pressure (depends on manufacturer). During this process, the gearset literally cuts into the pressure plate. This ultimately increases efficiency, but also creates a LOT of contamination. The contamination isn't a problem because the test stands are designed to handle it.

Now, imagine the pump in the field. If you increase relief pressures, you take the pump above the factory cut-in conditions, and the pump will cut in FURTHER. This literally means the gear set cuts away more material as the pressure seats the gear set further in the pressure plate.

The results are that shavings are produced and dumped into the hydraulic system. I have a LOT of experience with customers in the field damaging their systems this way. Typically the shavings end up in the valves or chew up seals. If the dealer checks the relief pressures and determines that the system is above spec, warranty is void!

Bottom line -don't think you get a pressure bump for free. You are introducing large particle contamination right in the heart of your system. You are risking waranty (if tractor is still under warranty).

FYI piston pumps are not subject to this situation.

IowaAndy

 

[3RRL]

I did a search and the only thing I found was a thread on an Exploding Hydro Filter
In the first post near the bottom, the poster says the factory spec is 1840psi for the BX24.

 

[Skyco]

Workshop manual says 1778 to 1849 at maximum engine speed, oil temp from 104 to 122degF on one page but then oil temp is shown as 113 to 131degf on another page.....so I'd say around 120degF is good

 

[Zick]

Do you have any pictures of your test setup and where you shimmed exactly?

 

[dfkrug]

Some of our tractors use gear pumps for aux. hydraulics.

Aluminum gear pumps undergo a 'cut-in' at the factory.....

All CUTs I have had use gear pumps.....I assume steel gears inside aluminum
housings. The ones I have dissassembled are built that way, like engine
oil pumps and HST charge pumps. What tractors use piston pumps for AUX
hydraulics? I know piston pumps are used in HSTs......

It is interesting to note what the hydraulic system pressures designed into
the various CUTs are. It says something about how robust the machine is
and/or how good the hyd pump is. It seems many tractors in the 30hp/3000#
range have 2000psi hyd systems and many of the same size have 2500psi
systems, from brand to brand. Sub CUTs seem to be mostly under 2000psi.

 

[Just2quickz28]

Subscribed. I have a ATI quick attach on the FEL of my BX 24 and would at some point like to put a bucket grapple on with a 50lb quick attach and a 80lb grapple that would cut the lifting capacity down.

 

[310-510]

Do you have any pictures of your test setup and where you shimmed exactly?

On my BX24, it is close to the left rear tire (as seated facing forward) and the bolt faces the rear of the tractor.

In the next week or so, I should have a little breathing room and pictures will be taken with the location and real world examples of lifting.

 

[Zick]

On my BX24, it is close to the left rear tire (as seated facing forward) and the bolt faces the rear of the tractor.

In the next week or so, I should have a little breathing room and pictures will be taken with the location and real world examples of lifting.

Thanks, I'll have to check it out.
Can't wait to see your results.

 

[310-510]

Here are the real world pictures promised.

When lifting the backhoe, the front bucket will not lift the hoe, so I start with a slight tip on the pallet.
Then just curl the bucket. PS. There is not enough curl power either. My BIL has to exert about 75 pounds of additional force to end up with the result in the second picture.



Of course, the tractor has no trouble lifting the 250 pound boxblade that has an additional 300 pounds of ballast.



The toughest item to lift and move is the 6" wood chipper. It is over 800 pounds and my BIL is required to stand on the flail mower to keep the back end on the ground. Once again, the loader will not lift or curl the chipper, however, with the BIL, it is movable.



I believe the loader would lift any and all implements I have if the weight of the implement was "in the bucket" and not 4' out in front of the bucket.

 

[Just2quickz28]

I am wondering how the Bxpanded forks can lift the backhoe as shown in this demo. Forks Carrying Backhoe if your set cannot lift the backhoe on its own. Are your forks really heavy duty? I don't think the pallet makes that much of a difference.

 

[Zick]

I am wondering how the Bxpanded forks can lift the backhoe as shown in this demo. Forks Carrying Backhoe if your set cannot lift the backhoe on its own. Are your forks really heavy duty? I don't think the pallet makes that much of a difference.

Watching that video, BXpanded doesn't actually lift the backhoe. They just curl it up just like carsce said he had to do. carsce also has a thumb on his backhoe but I doubt that adds a lot of weight.
Edit, after watching it a couple more time. It does seem like the BXpanded setup has no problem curling it, and could possible lift it up if they tried.
What's the weight of that backhoe?

Also when I asked about the weight of the BXpanded forks, they told me they were only about 40lbs for the set.
Depending on how heavy duty carsce made his forks, they could weigh almost double that. My neighbor made some heavy duty forks and his are around 80+ lbs. Mine are in the 50-60lb range I'd say.

 

[310-510]

As you can see in the picture of backhoe on the pallet, the backhoe is farther away from the bucket making the leverage point worse. If I could get the entire backhoe in the center of the bucket, lifting would be no problem.

I read somewhere the BT601 backhoe shipping weight is 617 pounds.

Zick,
Good observation on the curl. Yes, the thumb does add some weight way out front and when I chained the backhoe into the bucket (similar to BXpanded), there was no trouble curling the backhoe till it was almost all directly over the bucket, then lifting.

The pallet is much faster for loading and unloading in the trailer as opposed to getting off the tractor and chaining the backhoe to the bucket. (ok, just a couple of minutes faster)

 

[radioman]

The BX 24 backhoe weighs 280 lbs. According to kubota manual the loader is rated to lift 235lbs. go figure. this probably why the curl is needed first since the breakout force is higher then lifting.

 

[dfkrug]

The BX 24 backhoe weighs 280 lbs. According to kubota manual the loader is rated to lift 235lbs. go figure. this probably why the curl is needed first since the breakout force is higher then lifting.

Switch to kilograms from pounds, RADIO, and your specs are correct. It is
amazing the BT601 hoe is ONLY 617 lbs....it seems stoutly built.