How to Check the Performance of Car Shock Absorbers

Shock absorbers are crucial for vehicles frequently driven on rough or uneven roads. Typically installed as part of the suspension system, a malfunctioning shock absorber can shorten the lifespan of various vehicle components and significantly compromise ride stability, resulting in an uncomfortable, bumpy experience for passengers. It is highly recommended to inspect the shock absorbers before setting out-especially before long trips involving rough terrain-to ensure they are functioning correctly.

Here are some methods to check the performance of your shock absorbers:
1. Drive at a low speed and brake sharply; if the vehicle shakes violently and the ride feels uncomfortable, the shock absorbers are likely faulty.

2. Press down firmly on the bumper and release it; if the vehicle bounces two or three times before settling, the shock absorbers are working properly.

3. Drive the vehicle for 10 km on a rough road, then stop and touch the shock absorber housing. If it does not feel warm, there is no internal resistance, indicating the shock absorber is not functioning. You can try adding an appropriate amount of lubricating oil and testing it again; if the housing heats up, the unit was simply low on oil and needs to be topped up. If it still does not heat up, the shock absorber has failed.

4. Remove the shock absorber, hold it upright, and clamp the lower mounting eyelet in a bench vise. Pull and push the piston rod vigorously several times; you should feel steady resistance, with the resistance during the upward pull being greater than during the downward push. If the resistance is unstable or nonexistent, the unit may lack oil or have damaged valve components, requiring repair or part replacement.

Oil leakage is a common cause of shock absorber malfunction. If there are no signs of leakage, inspect the mounting pins, connecting rods, mounting holes, and rubber bushings for damage, broken welds, cracks, or detachment. If the aforementioned checks yield normal results, the shock absorber should be further disassembled to inspect for excessive clearance between the piston and cylinder, scoring on the cylinder walls, poor valve sealing, or imperfect contact between the valve disc and seat. Additionally, check whether the extension spring is too soft or broken; repairs should be carried out by refinishing components or replacing parts as necessary.

If the shock absorber is making noise, the issue is typically caused by collisions with the leaf springs, frame, or axle; damaged or detached rubber bushings; deformation of the dust cover; or insufficient fluid levels.

All four methods described above can effectively determine whether the shock absorber is functioning correctly. The first method is best used sparingly, as frequent emergency braking can damage the braking system. The second method-pressing down on the bumper-is highly recommended; it is convenient and yields clear results. Before embarking on a long-distance trip, one should also check for oil leaks, as these can lead to shock absorber failure while on the road.