Q: How to remove and install a fuel pump and fuel gauge sender unit on Ford Focus?
A: Dealer technicians use a special wrench to unscrew the pump/Fuel Level Sensor retaining ring, but ordinary tools can be used successfully. A combined fuel pump and Fuel Level Sensor unit is located in the top face of the Fuel Tank. The combined unit can only be detached and withdrawn from the tank after the tank is released and lowered from under the vehicle. With the fuel tank removed, disconnect the fuel line(s) by releasing their lugs using a small screwdriver. Note that the fuel supply line connector has a white band and the fuel return line (if used) has a red band. Make sure that both O-rings are recovered from each line as they are disconnected. Unscrew and remove the special retaining ring. The manufacturer specifies the use of their service tool 310-069 (a large socket/wrench with projecting teeth to engage the fuel pump/Fuel Level Sensor unit retaining ring's slots) for this task. A large pair of slip-joint pliers, or an oil filter removal strap wrench, may be sufficient for this task, but we used a tool made from two long bolts and two strips of metal. With the retaining ring removed, the pump/Fuel Level Sensor top cover can be withdrawn. Feed the wiring out through the opening, noting that the cover cannot be completely removed until the pump/Fuel Level Sensor unit is also removed from the tank. Turn the pump/Fuel Level Sensor unit counterclockwise inside the tank (this is quite stiff to turn), then carefully withdraw the unit, taking care not to damage the Fuel Level Sensor float or its arm. If not already done, remove the rubber seal from the periphery of the pump. The seal must be replaced whenever the pump/Fuel Level Sensor unit is removed from the tank. If required, the Fuel Level Sensor can be separated from the pump by squeezing together the lugs below its mounting at the side. Check the availability of a new Fuel Level Sensor separately, before removing the Fuel Level Sensor. Installation is a reversal of removal, noting the following points: Ensure that the pump/Fuel Level Sensor unit seats fully and squarely in the tank before twisting it clockwise to secure it. Check that the unit is firmly located before proceeding. Turn the pump/Fuel Level Sensor top cover so that the arrows on the tank and unit are aligned. Install a new rubber seal and tighten the retaining ring securely. Install the fuel tank.