In order to quickly attenuate the vibration of the frame and body, and improve the ride comfort and comfort of the car, the suspension system of the car is generally equipped with shock absorbers, and the double-acting cylinder shock absorber is widely used in the car.

Shock absorber is a vulnerable part in the process of automobile use. The working quality of the shock absorber will directly affect the driving stability of the car and the life of other parts, so the shock absorber should always be in good working condition. You can check whether the shock absorber works well in the following ways. Stop after driving 10km on the road with bad road conditions, and touch the shell of the shock absorber with your hands. If it is not hot enough, it means that there is no resistance inside the shock absorber and the shock absorber does not work.

At this time, appropriate lubricating oil can be added and then the test can be carried out. If the shell is hot, the shock absorber is short of oil, so it is necessary to add enough oil; Otherwise, the shock absorber is invalid. Press the bumper hard and release it. If the car jumps 2~3 times, the shock absorber works well. When the car is driving slowly and braking urgently, if the car vibrates violently, it means that there is something wrong with the shock absorber.

Remove the shock absorber to make it stand upright, clamp the lower connecting ring on a vise, and pull and press the shock absorber rod hard for several times. At this time, there should be stable resistance, and the resistance of pulling up (restoring) is greater than the resistance of pressing down. If the resistance is unstable or there is no resistance, it may be that the shock absorber is short of oil or the valve parts are damaged, so the parts should be repaired or replaced.

After determining that there is a problem or fault with the shock absorber, first check whether the shock absorber leaks oil or has traces of old oil leakage. The oil seal gasket and gasket are damaged, and the oil tank cover nut is loose.

If oil leakage is found, first tighten the nut of the cylinder head. If the shock absorber still leaks oil, it may be that the oil seal and gasket are damaged and failed, and a new seal should be replaced. If the oil leakage still cannot be eliminated, pull out the damping rod. If you feel that there is a hairpin or the weight is different, further check whether the gap between the piston and the cylinder is too large, whether the piston connecting rod of the shock absorber is bent, and whether the surfaces of the piston connecting rod and the cylinder are scratched or scraped.

If there is no oil leakage from the shock absorber, check the connecting pin, connecting rod, connecting hole and rubber bushing of the shock absorber for damage, desoldering, cracking or falling off.

If the above inspection is normal, the shock absorber should be further disassembled to check whether the fit clearance between the piston and the cylinder is too large, whether the cylinder is tight, whether the valve seal is good, whether the disc is tightly attached to the valve seat, and whether the extension spring of the shock absorber is too soft or broken. Repair by grinding or replacing parts as appropriate. In addition, the shock absorber will make noise in actual use.

This is mainly caused by the collision of shock absorber with leaf spring, frame or shaft, damage or falling of rubber pad, deformation of shock absorber dustproof tube and lack of oil. The cause should be found out and repaired.

After inspection and repair, the shock absorber should be tested on a special test bench. When the resistance frequency is 100 1 mm, the resistance of its extension stroke and compression stroke should meet the requirements. If there are no test conditions, we can also use an iron bar to penetrate the lower end of the shock absorber, step on both ends with our feet, and hold the upper ring with both hands and pull it back and forth for 2~4 times. When pulling up, the resistance is great, and when pressing down, it doesn't feel laborious. The tensile resistance is restored compared with that before repair, and there is no idling feeling, indicating that the shock absorber is basically normal.