Usually, the camshaft oil seal is replaced when the engine is being repaired and when oil is leaking
The leaking oil, splashing, falls on the timing belt, which deteriorates as a result.
With a 10 key, unscrew the three bolts securing the timing cover
Remove the front timing cover.
We insert a 10 head with an extension through the hole in the pulley and put it on the nut securing the rear cover of the timing belt.
With a head of 17, we loosen the tightening of the bolt securing the camshaft toothed pulley.
Remove the timing belt (see the article "Checking and replacing the timing belt")
Having unscrewed the mounting bolt, remove the camshaft pulley
Pry the oil seal with a screwdriver
Remove the camshaft oil seal
We apply a thin layer of engine oil on the working edge of the new oil seal and press the oil seal with a mandrel of a suitable diameter
We carry out the subsequent assembly in the reverse order.