The water pump is the heart of the Ford Focus cooling system and needs to be functioning properly to keep the rest of the engine in good shape. A faulty water pump could make the engine overheat, causing serious damage so it is necessary to replace the pump when it begins to fail.
Drain the cooling system from the radiator when the engine is cool.
Disconnect the negative battery cable before you begin.
Remove the accessory drive belt and take off the water pump pulley.
Take the front cover off the engine.
Remove the timing belt as well as the timing belt tensioner.
Loosen and remove the water pump bolts and take out the old water pump.
Replace the water pump in the engine, tightening the bolts to 13 feet lbs.
Install the timing belt and the timing belt tensioner.
Replace the front cover.
Reattach the water pump pulley and the accessory drive belt.
Reconnect the negative battery cable.
Refill the cooling system with coolant to the proper levels.
Start the engine and check for leaks when the engine reaches normal operating temperatures.
A sign that your water pump may need replacing is a leak in the coolant or loud noises coming from the cooling system. Disconnecting the negative battery cable may reset the on-board computer system or parts of the computer system, so be aware that you may have to reset certain settings.
Never attempt to drain the radiator when the engine is hot. The steam and the hot coolant within the radiator can cause serious burns.