<![CDATA[This study aims to analyze the factors causing the decline in the performance of the main cooling sea water pump in the main engine cooling process aboard MT. Sei Pakning, the impacts on the cooling system, and the preventive measures that can be implemented to maintain optimal pump performance. The research employed a qualitative descriptive method through interviews supported by Planned Maintenance System (PMS) documents, parameter observations, and other supporting documents. The results indicate that the decrease in pump performance can be identified through several indicators, such as reduced pressure shown on the pressure gauge, increased pump casing temperature, abnormal noise and vibration, and increased electric current indicated on the ampere meter. The main factors causing the decline in pump performance include impeller wear due to cavitation, excessive clearance between the impeller and mouth ring, dirty strainers clogged by debris, leakage in the pump system caused by improper alignment during installation, and problems in the electric motor. The decrease in pump performance results in an insufficient seawater supply to the central cooler, thereby disrupting the heat exchange process and causing the main engine jacket water temperature to exceed normal limits. This condition may lead to overheating and damage to engine components such as the cylinder liner and piston rings. Preventive measures that can be taken include regular visual inspections, strainer cleaning, monitoring pump running hours, implementation of the Planned Maintenance System (PMS), the use of spare parts according to specifications, and proper installation of pump components with correct clearance and alignment. With proper maintenance, the performance of the main engine cooling system can be maintained optimally.]]>
