How to Change a Fuel Filter on a 2004 Mazda Pickup

The fuel filter on a 2004 Mazda pickup is located on the right rear frame rail near the fuel tank. The fuel filter should be changed every 30,000 miles as part of the truck's maintenance schedule. The fuel filter strains out any impurities from the fuel before it reaches the fuel injectors. If even a speck of dust gets into one of the fuel injectors, it could clog the injector and cause the engine to run roughly.

• 1

  Locate the relay box near the driver's side fenderwell. Use the relay diagram on the cover to locate the fuel pump relay then pull it out with your fingers. Start the Mazda pickup and let it run until it stalls. If it just cranks over, crank it three or four times.

• 2

  Raise the right rear of the Mazda pickup with a floor jack then support it on jack stands. Clean off the fuel filter's hose connections off with a rag. Loosen the clamps on the hoses with a socket or a screwdriver, depending on the clamp. On the lines that use a quick-disconnect, insert a quick-disconnect tool onto the fuel line, squeeze it shut then pull the line off the filter.

• 3

  Unbolt the fuel filter from its bracket with the appropriate socket or wrench. Remove the fuel filter and discard it.

• 4

  Install the new fuel filter, making sure the arrow or the word "Front" is towards the front of the engine. Tighten the bracket bolt firmly. Slide the hoses onto the fuel filter. The lines with the quick-disconnect fittings should snap into place. Tighten the clamps on the lines (hoses). Start the pickup to ensure there are no fuel leaks. Lower the pickup off the jack stands with the jack once you have determined there are no fuel leaks.