Problems and service of shock absorbers. The most common shortcomings of shock absorbers include wear of joints and seals. The latter fault allows an oil leak, which negatively affects the work of the shock absorber. Therefore, the service of shock absorbers consists in checking their mounting and tightness as well as refilling or changing the shock absorber oil. Before refilling the liquid in the lever shock absorbers, clean the shock absorber and disconnect the lever of its lever.. Then add liquid through the filler opening,while moving the shock absorber lever. Shock absorbers with an expansion tank should be filled with oil only up to 3/4 its capacity, on the other hand, in shock absorbers without expansion tank, the oil level should reach the lower edge of the filler opening.