Can’t Rotate Your Excavator? Troubleshoot It This Way

What should you do if your excavator fails to rotate? Some fellow construction workers asked me this question, so I wasted no time sorting out these troubleshooting methods and summed up the following 10 causes:

Inspect the excavator accessory pressure sensor, which is located next to the rotary valve core of the multi-way valve. Replace it directly if damaged.

Keep the excavator in full rotary stroke and high-throttle condition, then measure if the rotary pilot pressure is at 3.0MPa. If not, check whether the pilot valve core of the excavator accessory is worn or damaged.

Check if the rotary pressure sensor and rotary P/B solenoid valve are functioning properly.

Inspect the short cover part of the shuttle valve core of the anti-reversal valve and the throttle hole for impurities. Check the long shuttle part of the valve core cover for abnormal wear; clean or replace the parts if necessary.

Confirm that the pressure of the P2 pump high-pressure sensor is within 10.0–15.0MPa when the excavator is in full rotary stroke and during operation.

Check if the current values and secondary pressures of the P2 unloading proportional valve and P2 pump proportional valve (excavator accessories) are normal.

Inspect the current value and secondary pressure of the travel straight proportional valve. When the throttle is high (regardless of neutral/operation status),

perform a standalone rotary motion to verify that the secondary pressure of the travel straight proportional valve is below 0.8MPa. If not, replace the proportional valve (excavator accessory).

Check the travel straight valve core and rotary valve core on the multi-way valve for wear, and inspect if their springs are broken.

When the excavator is in full rotary stroke and under overflow condition, check if the pressure of the rotary relief valve is 3MPa.

Drain a small amount of gear oil from the oil drain port of the rotary reducer and check for metal particles. Inspect internal components of the rotary motor (excavator accessories) for wear, and check the reducer gear surfaces for abnormal wear and chips.