In the use of vehicles, oil leakage often occurs, which will directly affect the technical performance of the automobile, resulting in the waste of lubricating oil and fuel, the consumption of power, the tidy vehicle capacity and environmental pollution. Due to the reduction of oil leakage and internal lubricating oil, poor lubrication and inadequate cooling will cause early damage to the parts and even cause accidents. First, the main reasons for the leakage of common vehicles are: 1. the quality, material or technology of products (accessories) are not good; there are problems in structural design. 2. improper assembly speed, improper surface cleaning, pad damage, displacement or failure to install according to the rules of operation. 3. the tightening force of the nut is uneven, the slipping of the wire is broken or loose and so on. 4., after sealing materials are used for a long time, the wear limits, aging, deterioration and deformation failure. 5. too much lubricating oil, too high oil level or wrong oil. 6. parts (side cover, thin-walled parts) joint surface deflection, shell damage, lubricating oil exudation. 7. after air plugs and one-way valves are blocked, due to the difference of air pressure inside and outside the casing, leakage often occurs in the weak part of the seal. Two, prevention of vehicle leakage measures 1. pay attention to the role of liner. The gasket between the stationary parts of the car (such as the joint end face, the end cover, the shell, the cover pad, the flat enamel cover, etc.) plays a leakproof and sealing role. If the material, production quality and installation do not meet the technical specifications, it will not play the role of sealing and leakproof, or even accidents. For example, the oil pan or valve cover is not easy to be compacted due to the large contact area, resulting in oil leakage. 2. all kinds of fastening nuts on the vehicle must be tightened according to the prescribed torque. Too loose pressure is not tight, and the liner will leak; too tight will cause the metal protruding around the screw hole or screwing the thread to cause oil leakage. In addition, if the oil drain plug of the oil sump is not tightened or loosed, it will easily cause the oil to run off, and then there will be an accident of "burning tile and holding the shaft". 3. change the failure oil seal in time. Many moving parts (such as oil seals and O-rings) on the vehicle will be thrown off the oil due to improper installation, the different necks between the journal and the oil seal edge. Some oil seals are too long to lose elasticity due to rubber aging. It is found that the leakage should be updated in time. 4. avoid one way valve and ventilation valve. As a result, the temperature inside the box increases, the oil and gas fills the whole space and the exhaust does not go out, thus increasing the pressure inside the case and increasing the consumption of lubricating oil and shortening the replacement cycle. After the engine's ventilation system is blocked, the piston's motion resistance is increased, and the fuel consumption is increased. Due to the difference of air pressure inside and outside the casing, it often causes leakage of oil at the weak part of the seal. Therefore, vehicles should be regularly checked, dredged and cleaned. 5. properly solve all kinds of tubing joint seals. The car coupling nut is often dismantling and easy to slide and break loose, which will cause oil leakage. Replace the union nut, use the grinding method to solve the cone sealing, so that the nut is pressed to solve the sealing problem. 6. avoid wheel shedding oil. The wheel hub bearing and the lubricating oil in the cavity are too much, or its oil packaging is not properly matched, the quality is bad and the aging is invalid; the wheel hub temperature is too high caused by the frequent brake, and the loose axle nut will cause the wheel hub to throw oil. Therefore, it is necessary to use the "cavity lubrication method (that is, proper lubrication)" to clear the blowhole.