Changing a sink tap washer is a straight forward job and should only take 1 hour if your time max. if you suspect a leak start from the faucet and work your way down, if the problem is coming from your sink tap then it is most likely the washer and needs to be replaced. The life of a washer is pretty reliable and can last for up to 10 to 15 years without any problems. The most common cause is a faulty faucet which if left too long, will eventually damage the washer. This article will go through the basics of changing a washer, there's nothing to it , so let's begin.
First and foremost you need to shut down the water supply. obviously to work on the faucet. You have either 2 options to do this, one is turning off the stopcock this will be located near the tap. Should your tap have no stopcock then you will have to resort to cutting the water supply from the main, which should be located outside usually near the public pathway in front of the house.
Once your are sure the water supply is off you can proceed with the next step. OK turn the tap on as far as it will turn, undo the faucet place a sink hole cover over the sink hole this will stop any foreign objects from falling into the sink hole while working. Dismantle the head of the tap, if there is a metal cover on the tap then this will have to be removed as well. Once this is removed then you should see a nut which contains the tap spindle which should also reveal the washer. Using a plain spanner slowly unscrew and carefully lift out the sink tap assembly this will be connected to the base and spout.
Once you have removed the assembly, you should have a clear view of the washer. The washer should be held in place by small nut, because there is a high risk of rust forming in this area the nut maybe hard to remove, in this case dip a little engine oil around the outside of the nut , wait for a few minutes and try again. If removed than before you put the nut back in,... dip it in some oil. Let's hope that nut is off?... because all that is left for you to do is take out the old washer and place in the new one. reassemble everything turn the main back on and check your work.