Kubota kx080 boom too fast and slams down.

[DavidRonk]

We bought a KX-080 Excavator at an auction recently and once it arrived we noticed that it is almost impossible to operate the boom lowering it at a reasonable rate. The slightest movement of the stick cause the boom to slam the bucker to the ground. It seems like there is a flow restrictor or something missing or broken. Any advice would really be appreciated.

 

[DustyRusty]

I sure hope that you got a good deal on it. Was it functional when you bid, or was the machine sold "as-is"?

 

[DavidRonk]

I sure hope that you got a good deal on it. Was it functional when you bid, or was the machine sold "as-is"?

Yes we did, it was sold as is. Any idea why the boom drops so hard?

 

[fried1765]

Yes we did, it was sold as is. Any idea why the boom drops so hard?

Cheer up......someone will come along here soon, with a solution.

 

[mikester]

new hose and didn't bleed the air in the lines?

 

[GreensvilleJay]

need more info !

Does every other function work smoothly ?
Does is raise up nicely ?

IE: The ONLY problem is lowering the boom ??

 

[DavidRonk]

Cheer up......someone will come along here soon, with a solution.

I figure so, no worries we have other equipment so we aren’t in a bind. I’m just not experienced in hydraulics

new hose and didn't bleed the air in the lines?

I'm not sure I will check with our mechanic.

 

[DavidRonk]

need more info !

Does every other function work smoothly ?
Does is raise up nicely ?

IE: The ONLY problem is lowering the boom ??

Yes

Yes everything works as it should except lowering the boom, it slams down.

 

[DavidRonk]

new hose and didn't bleed the air in the lines?

No air in the lines.

 

[TheOldHokie]

Yes we did, it was sold as is. Any idea why the boom drops so hard?

I have zero knowledge of that machine but excavators typically have load sensing hydraulic controls that meter flow and balance pressure based on pilot signals from the work ports on the valves. The system supplies individualized flow and pressure to each valve based on demand.

I would guess you have a load sense or metering problem in the valve bank that requires the attention of a technician knowledgable in those types of controls.

Dan

 

[DavidRonk]

I have zero knowledge of that machine but excavators typically have load sensing hydraulic controls that meter flow and balance pressure based on pilot signals from the work ports on the valves. The system supplies individualized flow and pressure to each valve based on demand.

I would guess you have a load sense or metering problem in the valve bank that requires the attention of a technician knowledgable in those types of controls.

Dan

Thank you for the information Dan, I will look for a mechanic in my area that can help, I certainly do not have any experience at this.

 

[TheOldHokie]

Thank you for the information Dan, I will look for a mechanic in my area that can help, I certainly do not have any experience at this.

The brochure for that machine says load sense (presumably closed center) hydraulics and pilot (fly by wire) operated controls. You need an experienced heavy equipment technician with diagnostic tools and probably a copy of the WSM.

Dan