Is it possible to assess the condition of the shock absorbers?, not using instruments? To a large extent, yes. First of all, you should watch them from time to time, even though they are hidden deep in the undercarriage. You can check it from the outside, whether oil is leaking from the shock absorber. if so, the damping efficiency will soon drop to zero. Also inspect the top and bottom shock absorber mounts, preferably while rhythmically pressing down on the bodywork. This way you can judge with your eyesight, or where possible by placing your hand on the fastening, that the rubber located there is not broken or possibly, that the fastening screws have not loosened.
When the fasteners are in working order, putting a hand to them and rocking the car, to some extent we can determine the damping force of the shock absorber. Up while the body is moving – at the bottom, it should exert considerable force on the fastening, which we will feel as a clear compression and expansion of the rubber in the mount. This test shows particularly well any play and discontinuity in the shock absorber.
How it should behave solidly swinging (at a standstill) car body with functional shock absorbers? It is accepted, that when you move down, the return to the starting position should be carried out in one cycle, without further body swaying. In specialized workshops, shock absorbers are tested on a stand, without removing them from the car. Similar to manual examination, the chassis of the car vibrates, then after disconnecting the inducing device, sensor checks, how much it was possible to wake up and in how many cycles it returns to the state of rest. Appropriate tables for each car make and model allow you to evaluate, how does the obtained result compare to the values ​​required by the manufacturer and to the operation of the new shock absorbers. This method of research also allows us to conclude, whether both shock absorbers on one axle behave similarly, and this is of paramount importance for driving safety.
The spare parts market offers a wide range of shock absorbers of various types and manufacturers, which can be used in place of the worn ones, assembled during the manufacture of the car. In practice, we will meet with oil shock absorbers, gas, two-pipe and one-pipe systems. Please note, that the damping factor in all is always oil, and the name describes the design of the device.