Hello, all.
In addition to my B2920, which is the best investment I ever made when I walked into the dealer and laid $30k on the counter for the tractor, FEL, backhoe, tiller, rear blade, deck mower, etc, etc, etc, I have now acquired a 1984 KH-28L excavator.
I am loving the combination of the hoe to dig out trees and my B2920 with landscape rake to pull blackberry bushes out and drag dug-up roots off the soil as we clear property in preparation for building.
But...and there is always a big but...it turns out that someone swapped the pressure relief valve on the thumb from the extend side to the retract side on the KH-28L, as well as oversizing the thumb cylinder so that it has more pressure than the now-smaller bucket cylinder. All of that before I got it. Now that we have discovered this (the hard way), we will be swapping those lines.
On top of this, the bucket ram had previously been bent and straightened, as I found when I attempted to curl and crowd while pulling out some vine maple roots--and turned the extended ram into a banana.
After the first $900 bill straightening that ram to within .003, and then having it bend again, the hydraulic guys replaced the ram with a hardened steel one and now are going through all the pressures in detail. While my bent ram occurred with the thumb fully retracted (that is, the bucket cylinder was not bent due to interaction with a higher-pressure thumb), they want to make sure that we can dial the thumb pressure relief back to lower than the cylinder pressure to avoid overcoming the bucket with the thumb.
But I cannot find the operating pressure specifications in my KH-28L operator's manual, parts list, or engine WSM. I am missing the excavator WSM.
The hydraulic guys are going to mount a tee in line so they can test the pressure, but it would be most helpful to know what the intended pressures are here as well.
Anyone have a KH-28L WSM they want to sell? Or scan? Or even just provide the stock cylinder size & operating pressure specifications?
(And while we are at it, when I got the excavator, it was missing one of the track top rollers, and of course, the Kubota dealer says both "No longer available" and "None left in the country". I may have to have one manufactured, but if anyone knows of an excavator junkyard or has a SK-28L with parts for sale, I would be interested to find out where.)
In addition to my B2920, which is the best investment I ever made when I walked into the dealer and laid $30k on the counter for the tractor, FEL, backhoe, tiller, rear blade, deck mower, etc, etc, etc, I have now acquired a 1984 KH-28L excavator.
I am loving the combination of the hoe to dig out trees and my B2920 with landscape rake to pull blackberry bushes out and drag dug-up roots off the soil as we clear property in preparation for building.
But...and there is always a big but...it turns out that someone swapped the pressure relief valve on the thumb from the extend side to the retract side on the KH-28L, as well as oversizing the thumb cylinder so that it has more pressure than the now-smaller bucket cylinder. All of that before I got it. Now that we have discovered this (the hard way), we will be swapping those lines.
On top of this, the bucket ram had previously been bent and straightened, as I found when I attempted to curl and crowd while pulling out some vine maple roots--and turned the extended ram into a banana.
After the first $900 bill straightening that ram to within .003, and then having it bend again, the hydraulic guys replaced the ram with a hardened steel one and now are going through all the pressures in detail. While my bent ram occurred with the thumb fully retracted (that is, the bucket cylinder was not bent due to interaction with a higher-pressure thumb), they want to make sure that we can dial the thumb pressure relief back to lower than the cylinder pressure to avoid overcoming the bucket with the thumb.
But I cannot find the operating pressure specifications in my KH-28L operator's manual, parts list, or engine WSM. I am missing the excavator WSM.
The hydraulic guys are going to mount a tee in line so they can test the pressure, but it would be most helpful to know what the intended pressures are here as well.
Anyone have a KH-28L WSM they want to sell? Or scan? Or even just provide the stock cylinder size & operating pressure specifications?
(And while we are at it, when I got the excavator, it was missing one of the track top rollers, and of course, the Kubota dealer says both "No longer available" and "None left in the country". I may have to have one manufactured, but if anyone knows of an excavator junkyard or has a SK-28L with parts for sale, I would be interested to find out where.)