XCMG Swing Motor Seal Kit The reasons for hydraulic oil leakage in hydraulic pumps can be as follows: 1. Damaged seals: There are many seals inside the hydraulic pump, such as sealing rings, gaskets, etc. If these seals are damaged or aged, it can lead to hydraulic oil leakage. 2. Pump body wear: There is a gap between the pump body and pump shaft of the hydraulic pump. If these gaps are too large or the pump body is severely worn, hydraulic oil will leak out from between the pump body and pump shaft. 3. Excessive hydraulic oil pressure: If the hydraulic oil pressure in the hydraulic system is too high, exceeding the bearing capacity of the pump body and seals, it will cause hydraulic oil leakage. 4. Loose connection of hydraulic oil pipeline: If the pipeline connection in the hydraulic system is loose, hydraulic oil will leak out from the connection. 5. Unqualified hydraulic oil quality: If the hydraulic oil contains impurities or moisture, it can cause damage to the seals inside the hydraulic pump, leading to hydraulic oil leakage. When it is necessary to solve the problem of hydraulic oil leakage in the hydraulic pump, the pump body and sealing components can be inspected and replaced to ensure that the hydraulic oil pressure is within the normal range, check whether the pipeline connections are loose, and regularly replace the hydraulic oil to ensure that the quality of the hydraulic oil is qualified.