Many customers are reflected in the use of hydraulic jacks, it will appear automatically crawling phenomenon. This is what causes it? How to handle it. Xiaobian to introduce the six kinds of treatment methods, we want to help. 1) hydraulic jacks installed is not parallel with the rails. Should be adjusted or re-installation. 2) Hydraulic cylinder with air intrusion. Exhaust system should be introduced, or the maximum stroke of the hydraulic cylinder fast movement, forced exclusion of air. Hydraulic cylinder motion is too large a gap between the parts. With the gap should be reduced. 3) piston and piston rod coaxial bad. Shall be calibrated, adjusted. 4) of the hydraulic cylinder end caps seals too tight or too loose. Seals should be adjusted so that there is proper tightness to ensure smooth rod can be pulled back and forth by hand without leakage. 5) rod bent. Should straightening rod. Rod rigidity. Increase the diameter of piston rod. 6) hydraulic jack mounting position shift. Should check the hydraulic cylinder and parallel rails, and corrections. More information about hydraulic jacks, please log http://www.jstzhl.com/ inspection.