What Causes Excavator Arm Dropping?

[VonHazel]

Excavator arm dropping is caused by low arm pressure or low pilot pressure of the arm. Below is relevant information about excavator arm dropping: Excavator arm dropping: Also known as boom dropping, self-lowering, or pump failure. Arm dropping is a manifestation of weak excavator boom force - when the boom is raised, the arm or boom will automatically descend without joystick control. Manifestations: When an excavator experiences arm dropping failure, different symptoms may appear. The malfunctions can be roughly categorized as main boom dropping, arm dropping, mid-boom dropping, or normal operation when cold but dropping when hot, etc.