If there are signs of oil leakage through the camshaft seals, first check if the crankcase ventilation system is clogged and if its hoses are pinched, repair if necessary
If the oil leak does not stop, replace the oil seals.
Disconnect the wire from the negative terminal of the battery.
Set the piston of the 1st cylinder to the TDC position of the compression stroke ("How to set the TDC of the VAZ-21126 engine").
Remove the timing belt ("Replacing the timing belt of the VAZ-21126 engine").
Remove the camshaft pulleys ("Replacing the cylinder head gasket of the VAZ-21126 engine").
Remove the keys from the camshaft grooves.
Pry off the seals with a screwdriver.
Before installing new seals, inspect the sealing lips 1.
They should be smooth, without tears, dents and rubber sagging.
The springs of the 2 glands must be intact and unstretched.
Lubricate the cutting edges with engine oil.
To make it easier to press the seals, make small chamfers on their seating edges with a needle file or an emery wheel.
Lubricate the seal lips with engine oil.
Install the oil seals with the working edges inside the head of the block, carefully fill the working edges on the camshafts with a wooden stick
Press it all the way in using a suitable mandrel.
As a mandrel, you can use a suitable size socket from the toolbox.
Install all parts in the reverse order of removal.
In this case, install the intake camshaft pulley with the disk that ensures the operation of the phase sensor to the engine.
Install the exhaust camshaft pulley in the same way.
Adjust the tension of the timing belt and the alternator drive belt.