When operating a car, bearing failure is a very common malfunction. The cause may be incorrect drive belt tension, water getting in when driving through a deep puddle, etc. As the bearing deteriorates, the pulley starts to play. When the play reaches a critical value, the bearing starts to heat up and fails. In the most advanced cases, the bearing jams, and the inner race of the bearing rotates on the landing neck of the compressor cover. After this, the compressor has to be replaced, and this is a very expensive repair at specialized services.
In order to avoid unnecessary expenses, when inspecting the car, pay attention to unusual noises when the air conditioner compressor is running. If you suspect problems with the pulley bearing, remove the drive belt (see "Replacement of auxiliary drive belts") and turn the pulley by hand. The pulley should rotate on the bearing evenly, silently, without jamming. There should be no axial or radial play.
If necessary, replace the bearing without waiting for its complete destruction. Bearing replacement requires special equipment, so if necessary, contact a specialized service center for car air conditioners.