The following symptoms indicate a bad shock absorber:
- Additional vibrations of the body when driving over bumps in the road.
- An increase in the amplitude of body vibrations with successive road irregularities.
- Wheel bouncing when driving on a normal road.
- Involuntary skidding of the car during braking may be due to other reasons.
- Instability when turning due to poor track holding and vehicle skidding.
- Increased wear on tires with sheared tops (washing out) protector.
- A sign of defective shock absorbers is also the presence of a rumbling noise. This noise may also be due to other reasons, for example, loosening of mounting bolts and nuts, failure of wheel bearings and constant velocity joints. Therefore, before replacing shock absorbers, always check their condition.
The shock absorber can be checked manually. However, an accurate check of the shock absorber function is only possible with a shock tester or a special testing machine.
Manual check
1. Remove shock absorber.
2. Set the shock absorber to its working position, extend and compress it. The shock absorber should move evenly and smoothly throughout the entire stroke.
3. For gas-filled shock absorbers, with sufficient gas pressure, the rod itself returns to its original position. If the rod does not return, this does not mean that the shock absorber must be replaced. Its principle of operation is the same as that of a conventional shock absorber as long as there is no significant oil leakage. The damping effect of the shock absorber is also maintained in the absence of gas pressure. However, its noise performance deteriorates.
4. During the normal functioning of the shock absorber, slight traces of leaked oil are not grounds for its replacement. The rule of thumb here is that if the oil escaping from the stem seal is visible but does not extend beyond the lower spring cup, then the shock absorber is good. Minor oil leaks even have some advantage, as it lubricates the oil seal, which helps to increase its service life.
5. In case of significant oil leakage, the shock absorber must be replaced.