Here are some reasons why you might want to change the oil pump on a Cummins engine:

1.     Low oil pressure: A faulty or worn oil pump can cause a decrease in oil pressure, resulting in engine damage due to inadequate lubrication.

2.     Engine noise: Low oil pressure caused by a faulty oil pump can result in engine noise such as ticking or knocking sounds.

3.     Oil leaks: A worn or damaged oil pump can cause oil leaks, which can damage the engine and result in oil consumption.

4.     Reduced engine performance: A damaged or worn oil pump can cause reduced engine performance and power due to inadequate oil supply to the engine components.

5.     Overheating: Low oil pressure can lead to overheating of the engine components, causing damage and ultimately engine failure.

6.     Maintenance: Regular maintenance and cleaning of the engine oil and oil pump can help prevent issues such as deposits or corrosion, which can lead to reduced oil pump performance or failure.

In summary, the oil pump is a crucial component of the engine’s lubrication system, and it needs to be in good working order to ensure optimal engine performance and prevent engine damage. Regular maintenance and timely replacement of the oil pump can help prevent issues that may require oil pump replacement.