My excavator has been working for 800 hours, and now the cold car is working normally. When the car is hot, the operating lever is wrinkled, heavy and buzzing. No manufacturer came down. ...

Below the handle is the pilot oil circuit. The heavy handle indicates that the pilot pressure is too high. The maximum value of the pilot pressure is limited by the pilot relief valve. Even at the maximum value, the handle will not bounce, so the opening pressure of the pilot relief valve must be increased for some reasons.

These reasons are more likely: the hydraulic oil is dirty and the overflow valve is out of order.

Treatment method:

1. Check the cleanliness of hydraulic oil, change it if it is dirty, and at the same time replace the filter elements of all hydraulic systems and clean the valve core.

2. Check the pilot overflow pressure. If it is too high, reduce it to the normal value. If it cannot be adjusted, directly replace the pilot relief valve.