When the excavator is equipped with a breaker, it is easy to cause the excavator to work without action because it does not pay attention to the installation details. Based on an example, this article will explain how to deal with it when there is no action after the excavator installs the breaker. It is only for reference.
1. Fault phenomenon
During one construction of the excavator, the working device of non designated breaker is installed. The ATT pilot valve is stuck several times in a short time, and the ATT does not act.
2. Cause analysis
When the maintenance personnel went to the site for maintenance, they found that the alarm sign of "abnormal selection pressure sensor" appeared on the excavator, and all ATT handles of the excavator did not act. Further inspection found that the pilot valve core of ATT handle was stuck, and the oil return filter element was attached with iron filings and other yellow powders. In addition, during the maintenance, the maintenance personnel also found the following problems.
1) The user introduced the installation of EDT through the salesperson. The intermittent use time after installation was more than 30 hours, but the special overflow valve was not installed, resulting in improper crushing pressure limit.
2) The special oil return pipe for breaker does not return to the hydraulic oil tank directly, but returns to the oil tank through the radiator.
3) The flow when using the breaker is not adjusted. The flow used is 294, but in fact, the flow used should not exceed 230.
3. Check and handle faults
1) Check that the ATT pilot valve is stuck and clean it.
2) Check that the oil return filter element has iron filings and yellow powder, which is suspected to be powder such as brake pads.
3) Replace the hydraulic oil and return oil filter element.
4) Test the excavator, check the action and sound for abnormalities, and judge that the hydraulic system of the excavator is damaged, but there are no major abnormalities. The excavator can continue to observe and use
5) The breaker manufacturer inspected the breaker and confirmed that there was no fault.
6) The maintenance personnel shall continuously observe the machine for 2 hours, replace the hydraulic oil and filter element again, and adjust the flow to 230.
After these problems were solved, the ATT pilot valve stuck again the next day after the excavator was used, and it was used normally after cleaning. Check again on the third day of use. The excavator uses the bucket and works normally. There is no scrap iron in the back filter. Replace a new breaker, change the oil return pipeline, and install an oil port overflow valve for the excavator.
