The main reason why the CAT 320D excavator cannot move on one side

1.Fault in the overflow valve of the 320 excavator motor: The overflow valve is an important component in the walking system. If it malfunctions, it may cause power transmission to be blocked, affecting the force of unilateral walking.

2. Damage to the central rotary joint: If the oil seal of the central rotary joint is worn or broken, it may cause insufficient lubrication, affecting the smooth operation of the moving parts and resulting in unilateral walking failure.

3. Damage to the walking motor: If there is a malfunction in the mechanical structure inside the walking motor, such as wear, jamming, or damage, it may cause the excavator to not move on one side.

4. Track adjustment issue: If the wear on both sides of the track is not consistent, it can lead to uneven walking, which may be caused by improper track adjustment.

Troubleshooting and repair steps

1. Check the vibration and noise of the hydraulic pump of the Caterpillar 320 used excavator: First, check whether the vibration and noise of the relevant hydraulic pump are normal. If they are normal, it means that the mechanical part of the hydraulic pump may not be significantly damaged.

2. Check the return oil filter element: Check whether there is metal powder and particles in the return oil filter element. If there is no abnormality, then check the oil discharge situation of the pump's oil discharge hole. If there is no metal powder and particles, it can be preliminarily judged that the rotating components of the pump are not damaged.

3. Exchange the oil outlet pipe and feedback pipe of the main pump: By exchanging the oil outlet pipe and feedback pipe of the two main pumps, further determine the fault point. If the fault occurs on the other side of the action, it indicates that it is a problem with the pump itself, that is, a problem with the regulator.

Check the regulator: Check if there is a problem with the regulator, which may be due to the breakage of the large spring in the feedback chamber or the return spring of the small servo valve core, causing abnormal valve core position and affecting the pump's displacement adjustment.

Replace damaged components: Based on the inspection results, replace damaged components such as overflow valve, central rotary joint, walking motor, etc.