What is involved in fuel filter replacement?

• A. Replace fuel filter; prime and bleed system.
• B. Dipstick reading.
• C. Replace oxygen sensor.
• D. Change air filter only.

Answer: (A)

Priming and bleeding are essential steps when you replace a fuel filter. After installing the new filter, you must push fuel through the filter and remove any air that entered the lines. Priming fills the fuel system with fuel so the pump doesn’t pump dry, and bleeding releases trapped air from the lines and injectors. If air remains, the engine can have hard starts, misfire, or run poorly because fuel isn’t being delivered smoothly.

The other options don’t involve the fuel-delivery side: checking a dipstick reads oil level, replacing an oxygen sensor affects exhaust emissions, and changing the air filter alone doesn’t address fuel delivery or air in the fuel system.