Vehicle seals are an extremely common thing in cars. The often-mentioned BMW oil leakage problem, in many cases, by regularly replacing the seals, the vehicle can be restored to a good condition to a large extent.

The sealing ring can be said to be ultra-small investment and ultra-large output.

But do we need to follow the advice of a technician when we repair it? Is it better to use imported seals or domestic ones? How to choose the material?

Strictly speaking, many parts of the car require one-time use.

For example, the maintenance manuals of many car models require that a new gasket should be used every time the oil drain bolt is removed. Each time the valve cover is disassembled and assembled, a new seal ring needs to be replaced. After how many times the valve cover made of resin has been disassembled and assembled, a new cover needs to be replaced.

Under normal circumstances, the maintenance of ordinary street-use scooter is not frequent. During the service life of the car for more than ten years, the number of disassembly and assembly of these parts will not be many.

But this may not be the case for the cars of track players and performance enthusiasts.

Power load limit, harsh working conditions, and repeated disassembly and assembly. Therefore, we must have our own standards for maintenance. The original factory requirements are for reference only.

For ordinary players, if conditions permit, it is best to go to the team or a reliable modification factory to do maintenance, they know your modified car very well.

If you want to maintain it in an ordinary repair shop or 4S shop, you must have your own standards. It is not recommended to follow the advice of the technician.

Because only you know your usage scenarios and car conditions.

Among the various parts that need to be replaced at a time, the most common one is rubber seals.

If your car is an environmentally friendly paper oil filter element, only replace the core barrel and reuse the outer shell every time you replace it.

There is an O-ring seal on the shell.

Some brands of machine filters are packaged with a sealing ring, and some brands of machine filters are not matched.

If so, replace it with a new one. If not, it is recommended that you buy a new one yourself and replace it.

The oil filter base (oil cake) and the sealing ring on the oil hole bolt are deformed and damaged.

If the data during installation is incorrect, there is no pre-lubrication before installation, and it is rotated after installation, the sealing ring may fail immediately or fail to leak soon after use.

The sealing ring of this part is also recommended to be replaced every time you disassemble and assemble.

Before using high-content ethanol fuel, the sealing ring of the fuel pipeline should also be replaced with one that is more resistant to ethanol.

Imported is not necessarily good.

Taking into account the differences in atmospheric environment and gasoline and other factors throughout the year, some brands, origins or target markets' machine filters and other accessories may not be suitable for you. Also consider whether the sealing ring needs to be replaced.

The material is very important, don’t look at the color

The rubber rings look the same to the touch and smell, but their materials are very different, so you must pay attention when choosing them.

Common materials mainly include silica gel, nitrile rubber, fluorine rubber, neoprene, EPDM and so on. Color cannot usually be used as a criterion for judging materials.

The working temperature range of silica gel is relatively large, usually around -50°C~200°C, which is suitable for use in alpine regions.

The low temperature tolerance of fluorine rubber is poor, usually around -20°C. It is not recommended for northern riders to use it in winter, but its high temperature tolerance is very good, usually up to about 250°C.

The heat resistance of nitrile rubber is only about 120°C~130°C, so it is not recommended.

It's not loose or tight

The seal ring should not be crimped or stretched during use, so the inner and outer diameters of the rubber ring should match the groove diameter.

The wire diameter should be able to be fully filled in the groove without excessive overflow. Taking into account that the size of the rubber ring will change with temperature, it will also be affected by the composition of the oil.

So when choosing a size, you must carefully consider its size.

Generally, when the rubber ring is in the groove, it should be slightly stretched. Its length is extended by 1% to 5% is a more reasonable range.

If there is no old sealing ring, it is necessary to calculate the required sealing ring size by measuring the size of the groove. The commonly used calculation methods are:

1. Measuring the inner and outer diameter of the tank

2. Calculate the inner diameter of the rubber ring: ideal inner diameter = inner diameter of the groove/1.02

The minimum inner diameter of the rubber ring = ideal inner diameter * 0.97

The maximum inner diameter of the rubber ring = ideal inner diameter * 1.01

If there is an old seal ring, you can directly measure the data of the old seal ring.

It is best to use a special measuring cone to measure.

If there is only a caliper, it should be noted that the sealing ring cannot be deformed during measurement.

It is best to place the sealing ring on the desktop for measurement. Do not touch the sealing ring with your hands or tools during the measurement, but only contact the sealing ring with a caliper, so as to avoid the deformation of the sealing ring affecting the measurement result.

The wire diameter should be larger than the groove depth and smaller than the groove width. For the common static seal ring on the car, the compression ratio of the cross-sectional area of the rubber ring should be 60%~90%, that is, the cross-sectional area after installation is 60%~90% of the cross-sectional area before installation.