
Failures of hydraulic pumps are usually characterized by high-pitched noise, high heat, fluid contamination, and leakage.
Contaminated fluid is the main reason for pump failure and that can be classified into two main types, chemical contaminants and particle contaminants.
Chemical Contaminants
Chemical contaminants mean the fluid is contaminated by water, heat, air, pressure, etc.
Water is the most common contaminant and it can lead to a whole host of problems. When the hydraulic oil is contaminated by the water, the hydraulic pumping system will suffer from both chemical and particle contamination. The diluted hydraulic oil causes rust in the components of the system, resulting in accelerated metal surface wear due to reduced lubrication.
Similar to water contamination, heat can also lead to the deterioration of the oil.
When air passes through the system, a lot of small air bubbles will be produced due to pressure changes and the control of the system will be lost.
Particle Contaminants
The most common particulate contaminants are metal particles from wear and dirt intrusion.
The small size of particle contaminants is usually not going to bring serious damage, as the hydraulic oil protects the parts in the system. Whereas, if the contaminants are too large to pass the clearance between the part surfaces, increased friction will lead to worse damage.
Therefore, if the machine overheats, leaks oil, or makes a loud noise, please check it immediately.
Tips
To ensure that the hydraulic system is working properly, the owner should check the oil level regularly. If it is above or below the required level, the owner should do more investigation. Also, make sure the hydraulic oil filter is working properly to remove contaminants.

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