In order to quickly attenuate the vibration of the frame and body and improve the smoothness and comfort of the car's driving, shock absorbers are generally installed on the car suspension system. The double-acting cylinder shock absorbers are widely used in cars.
Shock absorbers are vulnerable parts during the use of cars. The quality of the shock absorber will directly affect the stability of the car's driving and the life of other parts. Therefore, we should keep the shock absorber in good working condition. The following methods can be used to check whether the shock absorber is working well.
1. Drive the car on a road with poor road conditions for 10km and then stop. Touch the shock absorber shell with your hand. 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, you can add appropriate lubricating oil and then test it. If the shell is hot, it means that the shock absorber is short of oil inside. You should add enough oil, otherwise, it means that the shock absorber is ineffective.
2. Press the bumper hard and then release it. If the car jumps 2~3 times, it means that the shock absorber is working well.
3. When the car is driving slowly and emergency braking is applied, if the car vibrates violently, it means that there is a problem with the shock absorber.
4. Remove the shock absorber and stand it upright, clamp the lower connecting ring on the vise, and pull and press the shock absorber rod several times. There should be stable resistance at this time. The resistance when pulling up should be greater than the resistance when 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. Repair or replace the parts.
After determining that the shock absorber has a problem or fails, check whether the shock absorber is leaking oil or has signs of old oil leakage.
If the shock absorber does not leak oil, check whether the bushing is damaged, desoldering, cracked or falling off. If the above inspection is normal, the shock absorber should be further disassembled to check whether the clearance between the piston and the cylinder is too large, whether the cylinder is pulled, whether the valve seal is good, whether the valve disc fits tightly with the valve seat, and whether the extension spring of the shock absorber is too soft or broken. According to the inspection of the shock absorber connecting pin, connecting rod, connecting hole, rubber, etc., repair it by grinding or replacing parts.
In addition, the shock absorber may make noises in actual use. This is mainly caused by the collision between the shock absorber and the leaf spring, frame or shaft, damage or detachment of the rubber pad, deformation of the shock absorber dustproof cylinder, insufficient oil, etc. The cause should be found out and repaired.
After the shock absorber is inspected and repaired, the working performance test should be carried out on a special test bench. When the resistance frequency is 100±1mm, the resistance of its extension stroke and compression stroke should meet the requirements, indicating that the shock absorber is basically normal.