your mechanic is partially right, but you can bleed it thru your valve lever height adjuster, there is a small bolt which you can loosen and air trap will be released at that junction (do it while the engine is running and be careful to follow safety precautions. Also try to lower the height of your rear suspension, it will soften the hydraulic strut, and maybe give you a softer ride. Are you sure the aircell are ok ? (even thought their new).