A. Before fault maintenance is performed, it is advantageous to inspect and test to avoid wrong actions for maintenance. B. Inspect whether air pressure of steering wheel is enough, whether both sides are equal and whether wheels are worn. C. Inspect oil mass in oil tank is enough and whether is within the specified oil level. D. Inspect whether oil filter is clean and smooth E. Inspect whether flexible pipe is twisted, whether kinking is appropriate and is blocked. F. Inspect whether power-assisted steering oil pump belt slips. G. Inspect whether the following connections are obviously damaged or are not adjusted. (1). Joystick and universal joint; (2). Steering arm, draw bar, draw bar joint and universal joint; (3). Loosening situation of each steering connection.