These are basically little oil pumps that have a piston inside. The piston will push the oil or hydraulics through tiny holes and valves. The valves and holes are inside the piston that assists with control of the resistance and movement. Because only a small amount of oil is let through the tiny holes or orifices, the piston will get slowed down which will also decelerate spring and suspension movements.
There are also different types of shock absorbers that were manufactured for the different cars. The different types include Conventional Telescopic, Strut Type and Spring Seat shock absorbers.
Conventional Telescopic – these are the standard devices that are so cheap that a mechanic would rather replace than repair. They can be used for front and rear suspension.
Strut Type – these were made specifically for heavier loads. Part of the system is equipped with a strut to withstand the heavier loads on bigger vehicles. Certain parts of this model can be repaired whilst others need to be completely replaced.
Spring Seat – these versions are the two previous shock absorbers almost combined into one. The Spring Seat is the suspension unit and damping unit all in one. They can’t cope with heavy loads like the Strut Type. Sealed off parts would need to be completely replaced instead of repaired.