After determining that the shock absorber has a problem or failure, you should first check whether the shock absorber is leaking or has traces of old oil leakage.
The oil seal washer and sealing washer are broken and damaged, and the oil storage cylinder head nut is loose. It may be that the oil seal and sealing washer are damaged and invalid, and new seals should be replaced. If the oil leakage still cannot be eliminated, the shock absorber should be pulled out. After a while, check whether the gap between the piston and the cylinder is too large, whether the shock absorber piston connecting rod is bent, and whether the surface of the piston connecting rod and the cylinder tube are scratched or pulled.
If there is no oil leakage from the shock absorber, check the shock absorber connecting pin, connecting rod, connecting hole, rubber bushing, etc. for damage, desoldering, cracking or falling off. If the above inspection is normal, you should further Disassemble the shock absorber, check whether the matching gap between the piston and the cylinder is too large, whether the cylinder is strained, whether the valve seal is good, whether the valve disc and the valve seat are tightly fitted, and whether the extension spring of the shock absorber is too soft Or break, according to the situation, take the method of grinding or replacing parts to repair.
In addition, the shock absorber will have a noise failure in actual use. This is mainly due to the shock of the shock absorber colliding with the leaf spring, the frame or the axle, the rubber pad is damaged or falling off, and the shock absorber dust tube is deformed, and the oil Insufficiency and other reasons should be found out and repaired.
After the shock absorber is inspected and repaired, the performance test should be carried out on a special test bench. When the resistance frequency is 100±1mm, the resistance of the extension stroke and the compression stroke should meet the requirements. For example, the maximum resistance of the Jiefang CAl091 extension stroke is 2156~ 2646N, the maximum resistance of the compression stroke is 392~588N; the maximum resistance of Dongfeng Motor’s extension stroke is 2450~3038N, and the maximum resistance of compression stroke is 490~686N.
If there is no test condition, we can also adopt an empirical method, that is, use an iron rod to penetrate into the lower end of the shock absorber ring, step on both ends of the shock absorber, and hold the upper ring with both hands and pull it back and forth 2 to 4 times. There is a lot of resistance when pulling upwards, and it does not feel laborious when pressing downwards, and the resistance of stretching is restored compared with before repair, and there is no sense of empty travel, which indicates that the shock absorber is basically normal.