The fuel pump for the 2001 Ford Focus is installed within the fuel tank itself. Installing a new pump requires you to remove the tank from the car and remove the old pump from the tank first. Given the Focus' compact shape, this requires you to disconnect other components from the car and use special tools, in some cases, making this a more difficult job than on some other vehicles.
Siphon off as much fuel as possible if you can't wait until the fuel tank is nearly empty from running the car; use a vacuum pump or other siphon tool and deposit the fuel into a gas can.
Open the filler cap at the side of the car and remove the number 12 fuse from the fuse box. Start the car and wait for it to stall out, depressurizing the fuel system. Turn off the ignition and disconnect the negative battery cable.
Raise the rear end of the car, support it on jack or axle stands and block the front wheels with wheel chocks. Remove both rear wheels.
Detach the exhaust flange at the exhaust system's front by removing the nuts behind the flexible pipe. Remove the exhaust heat shield by removing its flat nut fasteners with a flare nut wrench and unhooking the mounting rubbers at the front and rear ends of the exhaust system (this requires a special tool).
Move the disconnected exhaust system underneath the car so it is clear of the fuel tank. Support the system's front end with another axle stand and support the rear end with the car's rear suspension cross-member.
Disconnect the filler pipe and vent hose from the tank; loosen their clamps with a screwdriver or pliers. Disconnect the charcoal canister by pulling off its vapor hoses, releasing the fitting at the hose, pressing the metal clip and lifting the canister upwards.
Disconnect the fuel lines from the fuel filter; pry out the insert to release the fittings.
Raise a floor jack with a block of wood under the tank, unbolt the tank strap with a wrench and a socket extension, unhook the straps and lower the tank with the jack.
Disconnect the fuel lines from the fuel pump module; use a small screwdriver to release the lines' fitting lugs. Note that the fuel supply line connector has a white band while the return line connector has a red band.
Unscrew and remove the module's retaining ring. You can use an oil filter strap wrench or large slip joint pliers, but a special Ford-issued service tool (310-069) is recommended.
Withdraw the top cover for the current pump and sender unit and feed its wiring out through the hole. Turn the pump and sender unit counterclockwise and withdraw the unit from the fuel tank. Remove the rubber seal on the pump's periphery.
Insert the fuel pump into the fuel tank. Make sure the pump is fully seated within the tank then turn it clockwise to secure it in the tank.
Connect the top cover for the pump and turn it so the arrows on the pump unit and the fuel tank line up. Install a new rubber seal on the fuel pump, then install and tighten the retaining ring with the same tool you removed it with.
Reconnect the fuel lines to the tank and lift it back into position on the car using the jack. Hook the straps back into place and secure them with the strap bolt.
Reconnect the fuel lines to the fuel filter, using the same red/white bands as a guide for the fuel pump connections. Reinstall the charcoal canister and reconnect the fuel filler pipe and vent hose to the tank with their clamps.
Maneuver the exhaust system back into place and connect the mounting rubbers, the heat shield and the exhaust flange.
Reconnect the rear wheels and lower the car. Pour the fuel back into the tank through the filler pipe on the side and reconnect the battery cable and the fuel pump fuse.
Turn the ignition key to the "On" position for about 10 seconds, turn it off and repeat twice more to repressurize the fuel system.
