Shock absorber leaks
Minor oil leak (fogging) on the piston rod seal is not a reason to replace the shock absorber.
If the oil stain is visible (but it is dull or dried with dust) and does not extend further from the upper shock absorber lock (piston rod o-ring) to the bottom plate (lining) springs -arrow-, the shock absorber is OK.
Note. A small oil leakage is an advantage, because in this case the sealing ring is also lubricated, as a result of which its service life is extended. This applies to the shock absorbers of the front and rear axles.
Shock absorber noise
Be warned that in noise complaints, shock absorbers are considered a common source of noise.
Noise can be caused by:
- faulty shock absorber
- loose suspension strut mount on the body,
- faulty thrust ball bearing,
- poor performance of the shock absorber,
- defective outer hinge,
- defective wheel bearing,
- breakthrough welding points of the body,
- loose and, accordingly, overtightened installed parts (exhaust system, specialized body design, covers, etc.).
Note. In the case of complaints where the noise is described as knocking or crackling, a test run must be carried out together with the customer, during which it must be established where, when and how the noise is heard (preferably - on a dry road with bumps).
Control of shock absorbers without gas pressure in the removed state
Damaged shock absorbers show up on the move with a knock - as a result of wheel bouncing, especially on a bad road, and must be replaced. The cause of failure is mainly oil leakage. The shock absorber can be compressed or stretched impetuously, with jerks. Before the shock absorber begins to act, it manifests itself in him "free play".
Note. Shock absorbers do not require maintenance. Shock absorber fluid cannot be topped up.
Control of gas-filled shock absorbers in the removed state
Damaged gas-filled shock absorbers also show up with a loud thud due to wheel bouncing and outwardly, usually a significant oil leak.
As a result of the manual inspection, it is possible to determine whether the shock absorber is damaged or not in the following way:
- Squeeze the shock absorber by hand. In this case, it is possible to displace the piston rod throughout the entire stroke with uniform resistance and without twitching.
- Release the piston rod. If the shock absorbers have sufficient gas pressure, then the piston rod itself returns to its original position.
If this is not the case, then this does not mean that it is absolutely necessary to replace the shock absorber, since in this case it will continue to act like an ordinary shock absorber (see notes below).
Note. The damping effect is also ensured without sufficient gas pressure, as long as there is no significant leakage of the shock absorber fluid. However, it is possible. that the noise level will rise. Not new (old) cars, you can use the existing shock absorber without problems even after the gas pressure has disappeared in it.
Sufficient gas pressure in the shock absorber helps to reduce the noise level of its course and improve its performance while driving on bad roads.