How to troubleshoot the shock absorber?
1. When the car is driving slowly and braking urgently, if the car vibrates violently, it indicates that there is a problem with the shock absorber.
2. Press the bumper firmly and then release it. If the car jumps 2 or 3 times, it means that the shock absorber is working well.
3. Remove the shock absorber and stand it upright, and clamp the lower end connecting ring to the vise. Pull and compress the damping rod several times, and there should be stable resistance at this time. The resistance of pulling up (recovery) should be greater than the resistance of pressing down. If the resistance is unstable or there is no resistance, it may be due to lack of oil inside the shock absorber or damage to the valve parts. Should be repaired or replaced parts.
4. Make the car stop after driving 10km on the road with poor road conditions, and touch the shock absorber shell by hand. If it is not hot enough, there is no resistance inside the shock absorber and the shock absorber is not working. At this time, you can add appropriate lubricating oil, and then carry out the test. If the shell heats up, there is a lack of oil inside the shock absorber, and enough oil should be added. Otherwise, the shock absorber has failed.
Determine the cause of the shock absorber failure
After determining that the shock absorber is faulty or invalid, first check whether the shock absorber is leaking or has traces of old oil leakage.
Case 1: If the shock absorber does not leak oil, 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, the shock absorber should be further disassembled. Check whether the matching clearance between the piston and the cylinder is too large, whether the cylinder is strained, whether the valve is well sealed, whether the valve clack is tightly attached to the valve seat, and whether the extension spring of the shock absorber is too soft or broken. According to the situation, it can be repaired by grinding or replacing parts.
Case 2: The oil seal washer and the sealing washer are broken and damaged, and the oil storage cylinder head nut is loose. It may be that the oil seal and sealing gasket are damaged and invalid. Replace with new seals. If the oil leak cannot be eliminated, the shock absorber should be pulled out. If you feel that there is a hairpin or the weight is different, check whether the gap between the piston and the cylinder is too large, whether the shock absorber piston connecting rod is bent, whether there are scratches or pull marks on the surface of the piston connecting rod and the cylinder.
Case 3: In addition, the shock absorber may cause noise in actual use. This is mainly caused by the shock absorber colliding with the leaf spring, the frame or the axle, the rubber pad is damaged or falling off, the shock absorber dust tube is deformed, and the oil is insufficient. The cause should be found out and repaired.