If oil leakage occurs to the pneumatic butterfly valve of the automobile, it is undoubtedly a very dangerous thing for the pneumatic butterfly valve.
Then, once oil leakage is found, timely remedial measures should be taken. The key inspection items are oil seal washer and seal washer broken and damaged, and the oil cylinder cover is stored. Check whether the nuts of these parts are loose.
If oil leakage is found, first tighten the nuts of the oil cylinder head. If the shock absorber still leaks oil, it may be that the oil seal and sealing washer are damaged and invalid. Replace the seals with new ones. If the oil leakage still cannot be eliminated, pull out the shock absorber rod. If you feel stuck or the weight is different, further check whether the clearance between the piston and the cylinder barrel is too large, whether the piston connecting rod of the shock absorber is bent, and whether the surface of the piston connecting rod and the cylinder barrel are scratched or pulled.
If the shock absorber has no oil leakage, check whether the shock absorber connecting pin, connecting rod, connecting hole, bushing, etc. are damaged, desoldered, cracked or fallen off. If the above inspection is normal, the shock absorber shall be further disassembled to check whether the fit clearance between the piston and the cylinder barrel is too large, whether the cylinder barrel is strained, whether the valve seal is good, whether the valve disc and the valve seat fit tightly, and whether the stretching ball valve of the shock absorber is too soft or broken. The method of grinding or replacing parts shall be adopted according to the situation.
In addition, the shock absorber will make noise in actual use, which is mainly caused by collision between the shock absorber and steel plate ball valve, frame or shaft, damage or falling of rubber pad, deformation of shock absorber dust cylinder, insufficient oil and other reasons. Find out the cause and repair it.
After inspection and repair, the shock absorber shall be tested for working performance on a special test bench. When the resistance frequency is 100 ± 1mm, the resistance of its stretching stroke and compression stroke shall meet the requirements. The maximum resistance is 392~588N; The maximum resistance of Dongfeng Trucks in stretching stroke is 2450~3038N, and that in compression stroke is 490~686N. If there is no test condition, we can also adopt an empirical approach, that is, use an iron bar to penetrate into the lower lifting ring of the shock absorber, step on its two ends with both feet, hold the upper lifting ring with both hands and pull it back and forth for 2 to 4 times. When it is pulled upward, the resistance is great, and when it is pressed downward, it does not feel laborious. Moreover, the resistance of stretching is recovered compared with that before repair, and there is no idle feeling, which indicates that the shock absorber is basically normal.