Leak detection method of automobile leakage

It is learned from some maintenance service providers that automobile leakage is mainly concentrated in air conditioning, oil circuit and waterway, and leakage may occur in systems with liquid flow. For car owners, it is terrible that car leaks are hard to find. The obvious leakage visible to the naked eye means that it is quite serious and not obvious, and no instrument has found leakage. So, how do we detect the leak for further maintenance? At present, there are seven commonly used leak detection methods in the market.

The simplest thing is visual inspection: when oil stains are found at a joint of the system, there may be leakage points here.

2. Soap detection: Nitrogen gas with the pressure of 10-20KG/CM3 can be filled into the system, and soapy water can be coated on all parts of the system, and the bubbling place is the leakage point.

The third is nitrogen detection, that is, nitrogen with the pressure of 10-20KG/CM3 is filled into the system, and the system is immersed in water, and the bubbling position is the leakage point.

Fourth, halogen lamp leak detection, that is, using liquefied petroleum gas without halogen substances. Ignite the leak detector, hold the gas pipe on the halogen lamp, and the nozzle is close to the place where the system may leak, and the flame color turns purple-blue, indicating that there is a lot of leakage here.

Five, gas differential pressure leak detection method: using the pressure difference inside and outside the system, the differential pressure is amplified by the sensor, and the leak detection result is expressed in the form of digital or sound or electronic signal. There are generally three leak detection methods: vacuum negative pressure leak detection and helium-nitrogen positive pressure leak detection.

Sixth, electronic leak detection, using the probe to move in all possible leakage parts, when the leak detection device gives an alarm, it shows that there are a lot of leaks here.

Seventh, fluorescence leak detection, using the principle that fluorescent agent will emit yellow and green light under the irradiation of leak detection lamp. Add fluorescent agent into the system according to a certain proportion, put on special glasses after the system runs for 20 minutes, and illuminate the outside of the system with a leak detector, and the leakage will show bright yellow fluorescence.

Car leakage should not be underestimated. The above is the leak detection method of automobile leakage that I sorted out, hoping to help friends with this problem.

In the use of vehicles, oil leakage often occurs, which will directly affect the technical performance of vehicles, lead to the waste of lubricating oil and fuel, consume power, affect the cleanliness of vehicles and cause environmental pollution. Due to oil leakage, the lubricating oil in the machine is reduced, and the parts are poorly lubricated and insufficiently cooled, which will cause early damage to the parts and even leave hidden dangers of accidents.

1 Pay attention to the function of cushion.

Gaskets between automobile fixed parts (such as connecting end face, end cover, shell, cover pad, flat enamel cover plate, etc.). ) plays the role of leakage prevention and sealing. If the materials, production quality and installation do not meet the technical specifications, it will not play a role in sealing and leakage prevention, and even accidents will occur. Such as oil pan or valve cover, because of the large contact area, it is difficult to compress, resulting in oil leakage.

2 All fastening nuts on the vehicle shall be tightened according to the specified torque.

If the gasket is too loose, it will leak water; Too tight will make the metal protrusion or thread around the screw hole slip, resulting in oil leakage. In addition, if the oil drain plug of the oil pan is not tightened or loosened, it is easy to cause oil loss, and then the engine damage accident of "burning tile and holding shaft" occurs.

3 Replace the failed oil seal in time

Many moving parts (such as oil seal and O-ring) on the vehicle will throw oil because of improper installation, misalignment and deviation of the journal and the oil seal cutting edge. Some oil seals will lose their elasticity due to rubber aging if they are used for too long. Found leakage should be updated in time.

4. Avoid blocking the check valve and exhaust valve.

As a result, the temperature in the tank shell rises, and the oil and gas fill the whole space and cannot be discharged, so that the pressure in the tank shell rises, the consumption of lubricating oil increases, and the replacement cycle is shortened. After the engine ventilation system is blocked, the movement resistance of the piston increases and the fuel consumption increases. Due to the pressure difference between the inside and outside of the box shell, oil leakage often occurs at the weak seal. Therefore, it is necessary to inspect, dredge and clean the vehicle regularly.

5. Properly solve the sealing of various tubing joints.

Vehicle union nut is often disassembled, which is easy to slip and break, which will cause oil leakage. Replace the union nut, solve its conical surface seal by grinding, and press the nut to solve the seal.

6. Avoid oil spilling from the hub.

Too much grease in the hub bearing and cavity, or improper assembly of its oil seal, poor quality and aging failure; Frequent braking leads to excessive hub temperature; Loose shaft nut will cause the hub to throw oil. Therefore, the "cavity lubrication method (that is, moderate lubrication)" must be used to dredge the exhaust hole.