On cars Focus recommended periodicity of replacement of candles makes 60 000 km of run. Replacement of candles spend only at the cold engine, by means of a special candle key, in a following order:

- Remove a wire from spark plugs;

- Turn away a candle on three turns and blow apertures under candles air under pressure. So you will avoid that at dismantling the dirt will get to apertures and will reach cylinders;

- Definitively turn out candles by means of a candle key and spread out on a workbench in that order in what they have been established on the engine;

- Put on a surface of a carving of new candles a thin layer of graphite greasing. Screw candles at first a hand and then a key on a turn quarter (90 ). It corresponds to the ordered moment of an inhaling 25 Нм;

- If you trust the used candles then before their installation clear a carving a brass brush. The further installation spend, as well as for new candles, but a candle key turn only on 15 as the sealing ring of the used candles already has been compressed.