To quickly dampen vibrations between the chassis and the car body, enhancing ride smoothness and comfort, most automotive suspension systems are equipped with shock absorbers. Currently, two-way telescopic shock absorbers are widely used in vehicles.

　　Shock absorbers are wear-and-tear components in the process of vehicle use. The performance of the shock absorbers directly affects the smoothness of the car's ride and the lifespan of other mechanical parts. Therefore, we should ensure that the shock absorbers are consistently maintained in optimal working condition. You can check whether the shock absorbers are functioning properly using the following methods.

　　1. Drive the car for 10 kilometers on a road with poor surface conditions, then stop. Touch the exterior of the shock absorber with your hand—if it doesn’t feel warm enough, it indicates there’s no internal resistance within the shock absorber, meaning it’s not functioning properly. In this case, you can add an appropriate amount of lubricant and repeat the test. If the exterior becomes warm, it suggests the shock absorber is low on oil and needs to be refilled completely; otherwise, it confirms that the shock absorber has failed.

　　2. Firmly press down on the bumper, then release it. If the car bounces 2–3 times, it indicates the shock absorbers are functioning properly.

　　3. When the car is moving slowly and brakes suddenly, if the vehicle vibrates violently, it indicates there’s an issue with the shock absorbers.

　　4. Remove the shock absorber and place it upright. Clamp the lower-end connecting ring securely in a vise, then firmly pull and push the shock rod several times. You should feel a consistent resistance—when pulling upward, the resistance to return should be greater than when pressing downward. If the resistance is unstable or completely absent, it could indicate that the shock absorber is low on oil internally or that the valve components are damaged. In such cases, the unit should be repaired, or the affected parts replaced.

　　After determining that the shock absorber is faulty or malfunctioning, first check whether it has oil leaks or shows signs of old, persistent oil seepage.

　　If oil leakage is detected, first tighten the cylinder cap nuts. If the shock absorber continues to leak, it may indicate that the oil seal or sealing gasket has deteriorated and failed—these should be replaced with new components. If the leak still persists after replacement, pull out the shock absorber rod. If you notice any sticking or uneven movement, further inspect whether the clearance between the piston and the cylinder tube is excessively large, or if the shock absorber piston rod is bent. Also check whether the surface of the piston rod and the inner wall of the cylinder tube have scratches or scoring marks.

　　If the shock absorber shows no signs of oil leakage, inspect its connecting pins, connecting rods, mounting holes, rubber bushings, and other components for damage, cracks, weld failures, or detachment. If these inspections reveal no issues, proceed to disassemble the shock absorber further, checking whether the clearance between the piston and cylinder tube is excessively large, if the cylinder tube has any scratches, whether the valve seals are intact, if the valve disc fits tightly against the valve seat, and finally, assess whether the shock absorber's extension spring is too soft or broken. Based on the findings, repair by either grinding or replacing the affected parts as necessary.

　　Additionally, shock absorbers may occasionally develop a noisy malfunction during actual use. This is primarily caused by the shock absorber colliding with the leaf springs, chassis, or axles, as well as issues such as damaged or detached rubber pads, deformation of the shock absorber's dust boot, or insufficient oil levels. In such cases, the root cause should be identified and the necessary repairs carried out.