Your vehicle's power steering supplements the steering system with hydraulic pressure. The Ford Focus, as well as every other car with hydraulic power steering, uses a pump to create the pressure that assists with steering. The basic steps to remove this pump are similar to the steps to remove any hydraulic pump. Some parts will have to be removed for access to the pump. Be aware that there are slight variations to the process depending on the exact model.
Remove the negative battery cable.
Siphon the fluid from the power steering reservoir.
Jack the vehicle and support it with jack stands, or raise it with an automotive lift, if available.
Remove the bolts from the accessory drive belt splash shield. Rotate the drive belt tensioner and remove the belt.
Remove the power steering pulley if there is not room to remove the pump and pulley as one assembly. Use a power steering pulley removal tool, or "puller." It may be easier to remove the pulley after the pump is out of the vehicle if there is room to remove the whole assembly.
Disconnect the power steering pump pressure switch electrical connector.
Unscrew the power steering line bracket nuts.
Disconnect the power steering pump pressure line and discard the O-ring.
Loosen the clamp in the power steering pump supply hose and remove the hose.
Remove the four mounting bolts from the power steering pump and remove the pump.
Place the old and new power steering pumps on a clean work surface to switch components. Skip this section if you are not installing a new pump.
Remove the hydraulic fittings from the old power steering pump and install them on the new pump.
Install the power steering pump pulley on the new pump. You may have to do this after the pump is installed if the pulley was removed while the pump was still in the vehicle.
Place the power steering pump into position and install the four mounting bolts. Torque them to 18 foot-pounds.
Moisten a new O-ring with power steering fluid and install it on the power steering pressure line.
Connect the power steering pressure line and torque the nut to 48 foot-pounds. Install the power steering line bracket and mounting nuts.
Install the power steering supply house and secure its clamp.
Connect the power steering pressure switch electrical connector.
Rotate the accessory drive belt tensioner and install the drive belt around the power steering pump pulley. Slowly release the tensioner.
Reinstall the splash guard and its mounting bolts.
Lower the vehicle and reconnect the negative battery cable.
Air must be purged from the brake system after any hydraulic component is removed. Follow the vehicle's instructions for filling and bleeding the power steering pump before driving the car anywhere.