1. Observe the residual oil stains on the hydraulic cylinder of the shock absorber: If the oil stains are very shallow and only slightly moist, it means the shock absorber oil impregnate; and if the oil stains are very deep and there is a large amount of sludge attached, Then it is the oil leakage of the shock absorber.
2. Check the working condition of the shock absorber: repeatedly press down on the body, or drive on a bumpy road. If the body is pressed down and the shock absorber works well and the shock filter effect is relatively good during driving, then it is a reduction. The shock absorber is oil impregnate; and if the damping rebound of the body is relatively weak, and the shock filtering effect during driving is relatively poor, it indicates that the shock absorber is oil leakage.