Car camshaft seal

How to detect  the camshaft oil seal failure

The camshaft oil seal examination should be performed during each scheduled inspection, when the camshaft is replaced or the cylinder head is repaired. The oil leakage at the place where the seal contacts the camshaft, cracks, breaks, deformation indicate that the part should be replaced. To objectively evaluate the oil seal condition, it is advisable to remove the camshaft pulley beforehand.

You may identify that the camshaft oil seal needs diagnosis by the following signs:

• oil traces on the belt or under the camshaft pulley, and on the inner surface of the crankcase cover;
• drive belt slipping;
• increased oil consumption;
• unstable engine operation.

Causes of the camshaft oil seal failure

Due to camshaft vibrations and rubber aging, the oil seal inner part breaks, loses its elasticity and warps, as a result of which the connection tightness is impaired. High quality fluorine rubber or silicone components are more adapted to such aggressive operation conditions and serve longer than usual rubber ones.

The camshaft oil seal may fail prematurely due to the vehicle long non-use or its storage outdoors: the prolonged absence of lubricant and temperature changes enhance the risk of the oil seal cracking.

Sometimes the camshaft oil seal looseness is caused by faults in the crankcase ventilation system, for example, by excessive crankcase gas pressure. The use of improper tools during installation also leads to the loss of the connection tightness.

Replacing the camshaft oil seal

If you have the appropriate equipment, replacing the component on your own is not difficult. For this you have to adhere to the following sequence of steps:

1. Remove the negative terminal from the battery.
2. Dismantle the drive belt.
3. While holding the camshaft pulley with special tools (pliers, handles, and a tap wrench), loosen and unscrew the fastening bolt.
4. Remove the pulley from the camshaft end.
5. Remove the oil seal from its mounting seat by picking it up with a screwdriver.
6. Press in a new seal using a mandrel.
7. Install the pulley, tightening its fastening bolt with the torque specified in the car's technical manual.
8. Adjust the timing belt tension according to the recommendations of the car manufacturer.

For the rear camshaft seal replacement, if it is provided in the engine design, you have to install the vehicle on the lift, disconnect the gearbox and the clutch. This procedure is quite time-consuming, and it is best performed at a service station.