Educate me on adjusting hydraulic system pressure

[JWR]

I am puzzled by this entire discussion. So far as I knew, the hydraulic pressure in a system was determined by the relief valve. Other things affect the pressure (especially DURING FLOW) at at some destination -- things like hose and fitting diameters, expansion strength or resistance in the hoses, length of hoses, etc. but I thought the relief valves set the ultimate pressure in a system. No ??

 

[Teikas Dad]

Most of the Kubota's sCUT and CUT's do indeed need the shims to adjust the pressure, others models just use a threaded stud and jamb nut configuration. BXPanded sells a kit that is targeted to smaller Kubota's and includes them.

Here is our video on testing, the procedure is the same no matter the color.

Thanks for posting that, it clearly shows how to check the pressure.

 

[Teikas Dad]

The WSM doesn't have a ton of information. Anyone know how many PSI each different shim thickness adds?

 

[kennyd]

I am puzzled by this entire discussion. So far as I knew, the hydraulic pressure in a system was determined by the relief valve. Other things affect the pressure (especially DURING FLOW) at at some destination -- things like hose and fitting diameters, expansion strength or resistance in the hoses, length of hoses, etc. but I thought the relief valves set the ultimate pressure in a system. No ??

I am puzzled by your post. The very thing that is being discussed is setting the max pressure by setting the pressure relief valve (PRV) and how to test it with a gauge. No??

 

[Tractor Seabee]

The WSM doesn't have a ton of information. Anyone know how many PSI each different shim thickness adds?
View attachment 545023

Your attachment does not open. The WSM does state the PSI/mm thickness. Page 5-S4. I stated the value in an earlier post on this thread.

Ron

 

[Blondie70]

I thought the PSV was the final step in protection of the system from overpressure. Is the working pressure not controlled by another device that regulates pressure (below the PSV setting)??? Wouldn't the working pressure be increased by shimming this device and not the PSV?
Confused and confounded in the Sunny South ...........(also puzzled)

 

[Tractor Seabee]

I am puzzled by this entire discussion. So far as I knew, the hydraulic pressure in a system was determined by the relief valve. Other things affect the pressure (especially DURING FLOW) at at some destination -- things like hose and fitting diameters, expansion strength or resistance in the hoses, length of hoses, etc. but I thought the relief valves set the ultimate pressure in a system. No ??

The procedure being discussed in this thread is adjusting the relief valve, to set the base operating pressure desired as established by the system relief valve. two methods. depending on OEM are shims under the spring or a screw adjusting pressure on the spring as previously stated. Location varies per OEM. Resistance to flow must be measured at the end of a specific circuit while operating. No flow the PSI does not change at that point. It should be minor difference unless something is awry. That's why WSMs are so valuable for those doing their own mechanic work.

Ron

 

[Teikas Dad]

Your attachment does not open. The WSM does state the PSI/mm thickness. Page 5-S4. I stated the value in an earlier post on this thread.

Ron

Thanks

 

[Ortimber]

Subscribed. I'm interested in learning more about this. Great discussion!

 

[Teikas Dad]

Your attachment does not open. The WSM does state the PSI/mm thickness. Page 5-S4. I stated the value in an earlier post on this thread.

Ron

My WSM for the B3200 has brake repair specifications on page 5-S4. Hydraulics are in section 8. I'll take a closer look and see if I can find the info.