1. The equipment design is unreasonable, the oil return pipe is too thin or the upper oil tank is too small, causing the oil circuit to be unsmooth and the oil temperature cannot be quickly reduced;
2. Use poor quality hydraulic oil or hydraulic oil of the wrong brand, low viscosity of the oil, or affinity with water, which will also cause heat;
3. The equipment is overloaded, and the machine is heavily loaded and heat is generated;
4. Improper adjustment of the return valve, or failure to replace damaged hydraulic parts in time, will sometimes generate heat;
5. There is leakage in the oil circuit, and there is oil pollution in the leakage place, because the oil will adsorb the dirt. In addition, overheating often indicates leakage. The joints that have leakage should be tightened at any time; if there is any abnormal sound, the hydraulic pump has a "click" sound, which suggests that air may enter into the air and cause cavitation, or Has been worn by dirt.