- Long-term vibrations of the body after driving over uneven surfaces.
- The body sways when driving over uneven surfaces one after another.
- Wheels bounce on a smooth road.
- Car "dive" when braking (there may be other reasons).
- Instability when turning and insufficient straight-line holding, vehicle vibration.
- Abnormal tire wear with scuffs on the tire tread.
- A faulty shock absorber is also recognized by the fact that knocking and ringing sounds are heard during movement. However, these noises can often have other causes, such as loose bolts and nuts of the chassis, faulty wheel bearings, CV joints. Always check the shock absorber before replacing, preferably on a special stand.
The shock absorber can be checked manually. Accurate testing of the shock absorber efficiency is only possible on a special stand (shock absorber installed) or using a special device.
Manual check
Remove the shock absorber.
Holding the shock absorber in the installation position, stretch and compress it. The shock absorber should move with uniform force and without jamming throughout the entire compression and extension stroke.
In gas-filled shock absorbers, the rod returns to the extended position automatically with sufficient gas pressure. If this is not the case, the shock absorber must always be replaced. The operating mode corresponds to the operating mode of a conventional shock absorber, as long as there is no significant oil loss. The shock-absorbing functions are also retained without gas pressure, however, the noise characteristics are deteriorated.
If the shock absorber is working properly, small traces of shock absorber oil are not a reason to replace the shock absorber. There is a firm rule: if an oil stain is visible and it does not expand from the upper shock absorber mount (shock absorber piston rod seal) to the lower nut of the spring, then the shock absorber can be considered in good condition. It is assumed that the oil stain will decrease, weaken or dry out from dust. A small oil leak is even an advantage, because it lubricates the seal and its service life increases.
If the oil leak is severe, replace the shock absorber.