Hydraulic Relief Valve Adjustment for Bx2230 and Bx1830

[kennyd]

Like many, I've been looking for a way to increase the lifting capability of my front end loader.

I've researched adding larger hydraulic cylinders and while this is more than doable, the shim change is a lot quicker, easier, and much less costly. I see the stock setup is configured with one solid flat shim and one flat washer. Knowing that by adding a shim simply changes the preload on the valve spring slightly therefore increasing the fluid output pressure. Instead of spending a lot of dough on the item + shipping, I'm wondering if adding a 12mm x 0.5mm flat stainless washer on top of this stack would result in the same performance change?

Comments are greatly appreciated!

Yes, a "shim" is just basically a washer-no real need for it to come from a dealer. BUT: please make or buy a gauge setup and take before and after measurements, do do not want to increase it to much. 10% or so seems to be the general consensus on that.

 

[ehenry]

Before I shimmed my BX22, hydraulic pressure was between 1600 and 1700 lbs. After shimming I'm at a tick over 2000 and finding the weak spots in the system. As it stands now I've had to have 5 cylinders rebuilt and have replaced almost all the hydraulic lines with the exception of the lines at the steering wheel. I probably have 3 sets of lines left to replace. I've no regrets raising the pressure. Everything that is being replaced and rebuilt is what came on the tractor when it was purchased new.

 

[Nightforce]

Before I shimmed my BX22, hydraulic pressure was between 1600 and 1700 lbs. After shimming I'm at a tick over 2000 and finding the weak spots in the system. As it stands now I've had to have 5 cylinders rebuilt and have replaced almost all the hydraulic lines with the exception of the lines at the steering wheel. I probably have 3 sets of lines left to replace. I've no regrets raising the pressure. Everything that is being replaced and rebuilt is what came on the tractor when it was purchased new.

From what I've read, and I'm no expert, most of these systems are designed to handle 2000 to 2500 PSI pressure. Do you think increasing the pressure to 2000 psi caused all the failures and repairs you've noted or would these be considered average due to normal wear?

 

[Nightforce]

Yes, a "shim" is just basically a washer-no real need for it to come from a dealer. BUT: please make or buy a gauge setup and take before and after measurements, do do not want to increase it to much. 10% or so seems to be the general consensus on that.

Will do...

Thank you Ken...

 

[JWR]

Pintodeluxe -- that is a GREAT post! One of the more informative and clear ones I have seen. Good info.

 

[Nightforce]

I'm not a cheapskate but I do like to do things myself when I can. I've been doing thing this way my entire life and since I'm in the age of maturity this will probably not change...LOL

I have a lot of tool maker tools in my garage when I need to raise the precision bar. One of those nifty little tools is a round shim cutter but the downside is it's in inches and not millimeters. The closest size shim to 12mm I can cut is .500.

12mm = .472

Has anyone measured the spring pocket or possibly tried .500 diameter shim to see if it fits?

I punched out 2 .500 diameter x 0.010 thick hardened steel shims. I've de-burred them and they're ready to try..

If anyone can add to this your input would be much obliged!

 

[ehenry]

NightForce, It's normal wear. Mostly all original hoses and I know none of the cylinders have had anything done to them prior to now. This BX22 was purchased at the end of '01 maybe '02 I don't really remember. I inherited it with 1200+ hours on it from a neighbor who bought it new. He passed in 2013. The tractor sat idle for the better part of two years before the estate was settled and I took possession of it.

 

[Nightforce]

I decided to add an intermediate step the improving the performance is the front end loader.

I bought some shims and adjusted the pump pressure to the front end loader. As we've all seen, Kubota sets this at about 1775psi. With the appropriate shims I was able to boost the output pressure to 2000psi at 2500rpm.



Before I make any changes to the cylinders, I felt this was a great intermediate step. I'll gauge it's performance throughout the fall and winter to see just how much of a difference adding 225 psi really makes...

 

[ehenry]

NighForce, considering that my BX22 is 16 years old and lived most of its life out in the elements before I became the owner, I'm fairly certain that raising the pressure contributed to my having to start replacing hoses and packings in the cylinders. I have no regrets raising the pressure. I'm just waiting for the lines that haven't sprung leaks to spring leaks and I'll get new ones made and keep on keepin on!!

 

[Nightforce]

eHenry, The pressure ratings for the hoses on my BX25D are 4,000psi. That said, they shouldn't even flinch resisting an additional 225psi. Like you, if a hose does go some years down the road I'll replace it and keep on keepin on!

Our machines are just that, machines. They at times are an extension of ourselves, our ideas, making them as individual as ourselves. They deserve a few tweaks here and there, a bump in pressure, additional lighting, unique attachments, customizing even factory buckets. After all, they are as unique and you and I.