Today I will talk about the reasons and inspection methods of several common hydraulic system failures of excavators, including insufficient pressure of excavators, insufficient power of excavators, and trembling of excavator booms.
1. The power of the excavator is insufficient. There are two types of situations, one is the lack of boom, bucket and right walking power. According to the analysis, the relief valve on the side of a main pump fails. After the inspection and verification, adjust the pressure or replace the overflow valve according to the regulations; if the power for the stick, swing and left walking is insufficient, the overflow valve on the side of the other main pump may fail. After inspection and verification, adjust the pressure as required or replace with a new valve.
2. The pressure of the excavator is insufficient. After investigation, the function of the main relief valve is malfunctioning, which makes it impossible for the hydraulic system to establish normal working pressure. At this time, you can check the pressure of the main relief valve, and then adjust or replace the new valve according to the specified pressure.
3. When the excavator pilot valve is in the neutral position, the boom, arm and bucket move quickly to the side without load, such as boom lowering and bucket opening. The reason may be that the port relief valve opens at a pressure lower than the specified pressure, so that the pressure of the port relief valve cannot support the load of the hydraulic cylinder. The crawling condition of the hydraulic cylinder can be inspected when the pilot control valve is in the neutral position. If the measured value of the hydraulic cylinder has exceeded the specified value, the pressure of the oil port relief valve must be checked and adjusted or replaced as required.
4. The power of a part of the excavator working device is insufficient. This may be the failure of the port relief valve in the faulty oil line. Check the pressure of the overflow valve in the faulty oil circuit, and then adjust the pressure as required or replace with a new valve. If the movement on both sides of the machine (retracting and extending) lacks sufficient power, you can check the oil filter in the oil tank. There may be broken seal fragments in the oil filter. Clean the oil filter and replace the seal.
