The components of the fuel pump are lubricated to minimize friction, overheating, and a life span of about 100,000 to 150,000 miles on the pump. With proper lubrication, there is minimal wear and tear on its moving parts, such as the rotor and impeller, which rotate several thousand times per minute to transfer fuel from the tank to the engine. Without lubrication, these components will suffer increased friction that will cut up to 20% of the pump performance over some time and cause more rapid wear.
The fuel itself is the main lubricant for fuel pumps. As it circulates inside the pump, it cools as well as lubricates the internal parts to maintain optimum operating temperatures, typically below 140°F. In pumps that aren’t properly lubricated, excessive generation of heat is common and could lead to damage to the pump motor, perhaps leading to early failure. In fact, overheating is considered by every automotive expert as one of the leading causes of pump failure, which again emphasizes that fuel not only acts as a coolant but also as a lubricant.
Fuel lubrication plays an important role in high performance pumps, which can be seen in racing or otherwise modified engines. For such engines, the pumps operate easily beyond 400 liters per hour flow rate conditions and hence there is more friction and heat generated. Racing fuel pumps are designed to operate in such an environment but depend on smooth fuel flow for lubrication of their moving parts against wear in such a high-duty cycle. Countless manufacturers like Bosch and Walbro engineer pumps with specific components that maximize lubrication for dependability at extreme usage.
In ethanol-compatible fuel pumps, the issue of lubrication becomes even more crucial as ethanol possesses lower lubricating properties compared with gasoline. If ethanol is not managed with a pump designed for the fuel type, then increased wear on internal parts may occur. Ethanol-rated fuel pumps contain special seals and coatings that help neutralize the drying effects of ethanol on components, enabling consistent lubrication and reducing component degradation up to 30%.
Fuel pump lubrication also minimizes the noise level. The properly lubricated pumps tend to run quietly, while the dry or partially lubricated pumps commonly generate clicking or whining noises, symptomatic of increased friction. For this reason, continuous lubrication is significant not only for performance but also to minimize operational noise.
To summarize, fuel flow effectively lubricates the Fuel Pump in order for long-term performance to be maintained and for fuel to be reliably delivered to the engine.