What can cause a fuel dispenser pump to bind during operation?

The correct answer relates to the misalignment of the rotor and idler gear in a fuel dispenser pump. This condition can cause mechanical interference within the pump assembly, leading to increased friction and ultimately causing the pump to bind. When the rotor and idler gear are not properly aligned, the components cannot function smoothly, which can result in the pump seizing during operation.

Proper alignment is crucial for the effective movement of fuel through the dispenser and for maintaining the integrity of the pump's mechanical systems. Misalignment can stem from improper installation, wear over time, or damage to the pump's components, which underscores the importance of regular maintenance and checks to ensure all components are positioned correctly.

In contrast, options related to voltage supply or power supply overload may affect the electrical performance and operation of the pump but do not directly interfere with the mechanical functioning in this specific manner. Excessive vapor buildup is more closely associated with fuel delivery and vapor recovery issues rather than the mechanical binding of the pump components.