Chinese mini Excavator hydraulic issue

[Capt1njohn]

I just bought a new 2025 TPM industrial TPM-18K mini excavator with the Kubota 722 Diesel. It has the pilot operated controls, so it is supposed to be less jerky than the ones without pilot controls. First time using it it was real jerky mainly because the main Turret bolts were loose. After I tightened them it was much better but still a little jerky. I read an article about putting springs on each of the 4 valve buttons or actuators on each of the joy sticks. So I bought a spring kit and installed them. It seemed to make it much more controllable. Only problem is the the control on the right. The boom up seems like it does nothing until the joy stick is all the way back. I'm not sure why that is. I bought two identical mini excavators at auction and I planned to sell one to offset the cost of the one I kept. The one that I sold the boom control worked normal the boom started to move a little as soon as you start to move the stick just like all of the other controls do. For some reason it seems like the pilot pressure coming from that particular actuator doesn't move pilot pressure until it is wide open. I'm not sure if there is a fix for that. I was hoping one of you guys on this forum might have an idea of what is wrong. Is it the joy stick or a valve under the deck that operates the boom up? I changed all the hydraulic fluid to AW46 as soon as I got the machine home and cleaned the metal and grinding particles out of the hydraulic tank and added new oil. I really didn't notice how it worked with the Chinese hydraulic fluid because I only used the controls to load and unload the units. Any help would be appreciated. Thanks

 

[mikester]

Contact the vendor. What? No support?

Enjoy your new hobby making cheap chinesium stuff work. I hope you are a good welder and have a machine shop in the garage to fabricate parts.

 

[oldnslo]

Is the valve accessible? If yes can you install a gauge in the pilot line on the valve section in question or swap pilot lines from a working section to this non-working section. It could a valve section binding or a faulty joystick.

 

[MattB4]

You may just have air in the boom control. Try running the cylinder in and out to full stop several times till the relief valve actuates.

 

[Capt1njohn]

Contact the vendor. What? No support?

Enjoy your new hobby making cheap chinesium stuff work. I hope you are a good welder and have a machine shop in the garage to fabricate parts.

Does any of the cheap chinesium stuff have support? Thats why I thought it was cheep! LOL I guess I could have paid 6 times as much for a name brand with support my back yard will never know the difference. I never buy extended warranty's anyway.

 

[Capt1njohn]

You may just have air in the boom control. Try running the cylinder in and out to full stop several times till the relief valve actuates.

I have put about 6 hours on the unit now I would think any air should have been blead out by now. I will try running the boom all the way out and back several times tomorrow and see if that does anything. Thanks for the input.

 

[2manyrocks]

Time for a specific forum for chinese mini excavators, skid steers and track dumpers? Seem like many new owners run into issues right off the bat.

 

[Tinhack]

Could be just a simple adjustment of the controls. Is the control valve cable operated or a Monoblock with a stick? Might be just a loose swivel under the boot.