The hydraulic pump is the most important component of the hydraulic system and any hydraulic pump-related malfunction can cause severe damage to the entire system, affecting performance and productivity. A hydraulic pump's short life can be a burden to machine operators and can be costly due to frequent repairs or replacements. There are many reasons for a hydraulic pump malfunction. But the frequent occurrence of pump problems requires a complete check of the system. The reasons may be contamination, incorrect selection of components, incorrect selection of oil, etc. The causes of hydraulic pump problems are discussed in this article. Pollution: Contaminants in the hydraulic system will change the properties of the oil and cause the oil to be polluted. In addition, sludge or varnish accumulated due to lack of maintenance or prolonged operation will also contaminate the liquid. These contaminants will reach the hydraulic pump through hoses/tubes when the system is running. ...