Everything else works fine. Just wont rotate it start to move and after a inch or 2 in either direction it stops. Engine or nothing bogs down. I have ordered a service manual and should have next week. I read on generic posts that can a few things but nothing direct for a hitachi ZX75US. Any idea what I should look at before manual arrives next week? Thanks
How is the fluid level in the swing motor? With no bogging down, I would more suspect a control issue.
Does it feel like it wants to move or just feels like it’s lazy.
It starts to move then after maybe a inch a abrupt stop...Both direction
I have a ZX55UR. It has a control module for the operation of the bucket and boom, and there are sensors that continuously tell the control module the position of the boom. If one of the sensors stops sending a signal (or sends a signal that is outside the program parameters), the control module cannot tell where the boom is, and shuts down hydraulic functions as a safety feature. The issue that you have could be a position sensor (or an electrical connection to a sensor).
Thanks for reply, All hydro work, moves, digs, etc, Just won't rotate. So even though helpful not sure its related. I will check the sensors though.. Thanks!
On a ZX75US ,I think you should be able to check the swing control pilot pressure when the monitor is in “service mode“ . To get into a Deere C series or Hitachi ZX -1 excavator service mode, press and hold the set button then key on or start. After bulb check release the button. Then use the select button to scroll. . The service mode available data list on the smaller machines is quite short compared to excavators 120C ,ZX110/120 and larger. See data list for the small excavators below .