Oil semi trailers are mainly used for large-scale oil transportation, with a tonnage generally around 40-60 cubic meters. There are usually two axle semi trailers and three axle semi trailers for transporting oil. The material of the square tank body of the oil transport semi-trailer is made of Q235A steel plate, and the tank body is equipped with multiple reinforced anti wave baffle plates. The lower end of the baffle plate has through holes to reduce the impact of oil in the tank body during vehicle operation and improve the strength of the tank body. The combined tank mouth is located at the top of the tank body, with a self-locking small cover above the large cover. A breathing valve is installed on the upper side of the large cover to ensure consistent atmospheric pressure inside and outside the tank; Equipped with static grounding wire. Install a pump oil system that takes power from the gearbox side through a power take-off, allowing for self suction and self discharge; Equipped with two oil extraction pipes and quick fitting fittings, with a suction head of 6 meters. Two fire extinguishers and special tools. The oil semi trailer is divided into two parts, the oil tank body and the skeleton or bracket that supports the tank body. Fault and maintenance methods: 1. Braking is not effective or slow. Reason: The clearance between the brake shoe friction pad and the brake drum is too large, and the brake shoe friction pad is excessively worn after adjusting the clearance. The replacement brake shoe friction pad air chamber is damaged, and the replacement air chamber air brake system leaks, causing a pressure drop. Check the leaking area, repair or replace parts. The emergency relay valve is not working properly, and replace it. 2. The brake cannot be released. The brake is slowly released. Reason: The system pressure is too low, Increase the pressure of the air brake system to the specified value. The brake return spring is damaged, the spring pipeline is replaced with a blockage, the emergency relay valve or quick release valve is inspected and cleared for poor operation, the brake chamber push rod stroke is checked and replaced for incorrect operation, and the adjustment is made again. 3. Reason for tire swing: loose wheel nuts, sintered or damaged axle bearings, bent axle bearings, excessive clearance between axle bearings, and correct tightening of bearing lock nuts, Replace the bearing lubricating grease and axle bearings on time; The tire is excessively worn, and the perpendicularity between the axle axis and the center line of the frame exceeds the standard. Adjust the distance between the two ends of the axle and the traction pin to be as consistent as possible. 4. The shaking resistance of the rocker is too high. Reason: Poor lubrication, additional lubricating grease, damaged bearings, replacement of bearings, gear eccentricity or severe wear. Disassemble and inspect the replacement parts for damaged screw threads, and replace the screw.