Due to their complexity and finely-tuned nature, fuel pumps are usually difficult to fix. Most contemporary fuel pumps are electric incorporating a motor, impellers, seals, and housing unit to maintain pressures between 40–70 PSI. It is then often cheaper and quicker to replace the whole unit than to repair each component if any of these internal parts fail or wear out. Buying a fuel pump motor for example can cost just shy of 70 percent of a new pump cost, risking the likelihood of failed supporting components as well in short order.
Fuel pumps typically deteriorate internally in high-mileage cars, resulting in a low flow rate and fluctuating pressure. After all, many mechanics will discover that in order to properly address these particular symptoms, specialty equipment is needed — something only a few elite and advanced repair shops ever have. Because disassembling and reassembling its internal parts requires higher precision (e.g. parts must be calibrated to within a few microns of one another to prevent leaks or pressure inconsistencies), a 2019 study by the Automotive Service Association found that labor costs to repair a fuel pump are 30% higher than fuel pump replacement.
Other fuel pump problems, such as a clogged filter or a weakened seal, are simpler; less so when you consider that the pump is usually buried deep within the fuel tank with very little room for access and you will have to set aside a chunk of time to drop the fuel tank, time that costs the consumer as it is labor-intensive work. One example is the labor to remove a fuel tank, which can be charged at 2-3 hours the average price of around $150 to $300 depending on the vehicle. This is why both mechanics and manufacturers recommend replacing rather than repairing, to prevent something that could fail and even affect your engine performance or fuel economy.
Interestingly, automotive expert Richard Hammond says of fuel delivery, “We often do find it quicker and safer to replace rather than repair. An industry that takes a meticulous approach — where precision and reliability are paramount, as manifest in this statement regarding fuel pump issues. They’re an important part of the engine, and if you have a job done badly, then you’re really going to end up with some major performance or safety issues.
A good Fuel Pump will need minimal repairs since it will have to deliver fuel at a minimum expenditure.