Yanmar SC2400 Hydraulic Pressure Increase

[sauer]

I am researching increasing my hydraulic pressure on my Yanmar Sc2400 to improve loader and 3 pt lift capacity.

I do have a digital copy of the shop manual, and it states do not exceed 1875psi. This note is referenced on the hydraulic circuit diagram for the power steering cylinder.

Hydraulic flow goes from second pump (with relief valve set at 1875psi) through the power steering valve, to the 3 point, to the loader.

Kubota BX owners (on internet forums) have increased their lift capacity by shimming their relief valve.

Yanmar does in fact sell similar shims for adjusting pressure, though their (and probably Kubota's) intent is for them to be used only is pressure is low (<1875psi). I'm leaning towards increasing to around 21-2200psi. I've already purchased shims from my dealer.

My questions are:

1. Has anyone actually done this with an sc2400?
2. Though the manual clearly states do not exceed 1875psi due to the steering cylinder - is this just extra caution/safety from Yanmar? Or does Kubota just have a beefier steering cylinder (I could not find specs for their cylinder)?
3. Kubota owners claim shimming only increases loader lift capacity. With the Yanmar I think both 3pt and loader lift will increase, because of how the hydraulics flow. Is this a correct assumption? Why does the 3pt lift not increase on the Kubota?

 

[Rock knocker]

Without going over your tractor, I would suggest not doing this at all.

 

[jbwilson]

I've thought about it because I have a very heavy 4 in 1 bucket which significantly reduces the payload capacity. In my head I would replace the fel cylinders with bigger bore ones accepting that cycle times will be a lot slower. But I'm sure in practice, I would regret making the change.

 

[Rock knocker]

Increase the pressure and/or the bore to increasing the picking capacity, and the next functions which will be threatened with failure are tipping, the boom structure and the front axle assembly in it's entirety.

 

[jbwilson]

I have done a fair bit of earthmoving with my tractor. While the tractor has held up well, the puny front tyres tend to prematurely give up the ghost.

 

[Dave M7040]

Buy a bigger tractor rather than destroying this one.
The engineers who design them no longer have large safety factors in their designs as it is too costly.

Once the loader arms are bend from having larger cylinders pushing on them or cylinders running at higher pressures, you are screwed.

Break the front axle and associated parts and you will find the cost of the repair parts exceeds the value of your tractor..

Try and sell it or trade it modified and no one will want to touch it.

It is nice to dream about upping the performance of your dream machine but entirely an unwise decision from a 70 year old who did far too much of that to too many vehicles.

Dave M7040

 

[jenkinsph]

I would not do it. If you need more lift you also need more tractor for stability and safety. Currently your tractor will lift about 700 lbs. to full height which is about half the machines weight. That is plenty for those front tires imo. and I have the same size front and rear on my mower.