ABYC Diesel Practice Exam

Which technician is correct regarding the routine replacement of impellers?

1. Technician A, who says they should be routinely replaced

2. Technician B, who suggests reversing the impeller’s direction

3. Both technicians are correct

4. Neither technician is correct

The correct answer is: Technician A, who says they should be routinely replaced

Routine replacement of impellers is essential for maintaining the proper functionality and reliability of marine diesel engines. Impellers, which are critical components in raw water pumps, can become worn or damaged over time due to continuous exposure to water, heat, and various contaminants. This wear can lead to decreased pump efficiency, overheating, or even complete pump failure if not addressed timely. Technician A's assertion about the necessity for routine replacement aligns with industry best practices and recommendations from manufacturers. Regularly scheduled inspections and replacements help ensure that the impeller remains effective, thus promoting the overall health of the engine cooling system. On the other hand, reversing the direction of an impeller, as suggested by Technician B, is generally not considered a standard practice. Most impellers are designed to work in a specific direction, and reversing this can cause damage or a failure to properly pump fluids, which reinforces that routine replacement is the prudent course of action. In the context of maintenance procedures, regularly replacing impellers helps prevent issues before they arise, supporting long-term engine reliability and performance.