What causes the shock absorber to have resistance when compressed but not rebound?
2 Answers
The reasons why a shock absorber has resistance when compressed but does not rebound are as follows: Since the rebound force of the shock absorber is provided by the shock-absorbing spring absorbing road vibrations and impacts, once the shock-absorbing spring is damaged, it will greatly affect the rebound force of the shock absorber. Below is relevant information about shock absorbers: Working principle: The working principle is that when the frame (or body) and axle experience relative movement due to vibration, the piston inside the shock absorber moves up and down, causing the oil in the shock absorber chamber to repeatedly flow from one chamber to another through different pores. Purpose: To accelerate the attenuation of frame and body vibrations and improve the vehicle's ride smoothness (comfort), most vehicles' suspension systems are equipped with shock absorbers.
I've been in auto repair for over a decade, and when I encounter shock absorbers that resist compression but fail to rebound, it's usually a classic sign of either leaked fluid or internal piston seizure. Shock absorbers rely on hydraulic pressure to dampen vibrations – once the fluid leaks out, the piston gets stuck in the compressed position and can't spring back. In some older vehicles, prolonged valve wear can also cause them to lock up. The check is straightforward: look for oil stains or rust marks on the exterior of the shock absorber, and press down on the spring area near the tire to test. Don't ignore this issue – driving without proper damping feels like having no suspension at all, leading to severe bumpiness, handling difficulties, and significantly increased skid risks during turns. I recommend stopping driving immediately and getting professional replacement. For routine maintenance, regularly checking for balanced tire pressure can help delay aging.
