If diesel oil and lubricant are compared to human blood, then the filter is human kidney. Since it is equal to the kidney, the importance must be self-evident, its working state is directly related to the performance and life of the engine. From the popularization of the "Three Common Rail System" to the "Five Common Rail System", although people have a deeper understanding of filters, they know that inferior filters can easily destroy expensive injectors, but they do not know that the wrong installation process is equally dangerous.
Maybe someone said, "It's not difficult to change the filter, just take it down and screw it up." Indeed, the replacement process is very simple, but many people have made irreparable mistakes in this simple process. What are the specific mistakes? That is to fill the filter with oil before installing it.

Lubricating oil is poured into it.
It is very common to fill the interior with oil before installing the filter. Most people do this whether they are diesel or oil filters. In fact, the method of filling the oil filter before installation is also understandable, because the cleanliness of the new oil is better, and the oil filter can not manually exhaust, after filling the oil, it can reduce the time when the oil reaches the lubrication part and protect the engine. But if the diesel filter is operated in this way, it will play the opposite role.
In fact, the method of pre-filling filters to avoid exhaust has a very long history, which can be traced back to the time when diesel engines were widely used. At that time, almost all diesel engines used mechanical pump fuel injection system, which did not require high cleanliness of fuel itself. In addition, the small displacement of hand oil pump and poor reliability made it very difficult to replace the filter after exhaust, so people at that time invented this flexible method of pre-filling and no exhaust. I have to admit that this method is really very effective.
Since the engine entered the common rail era, the fuel system, especially the injector, has become very sophisticated. A little impurity may lead to the scrapping of expensive injectors. At this time, many people continue to use the previous method of oil filling, resulting in the direct entry of unfiltered diesel oil into the filter. If the diesel oil contains particulate impurities in the inner chamber at this time, the wear and tear of the injector will be directly caused.
The correct replacement method is to remove the old filter, then install the new filter directly on the base of the filter, then loosen the bleeding bolt on the base or the oil pump, press the hand oil pump exhaust, until the new filter is filled up and no bubbles appear on the exhaust bolt. Because of the large area and capacity of the filter, the exhaust process may be slow. Don't be afraid of trouble, just press the hand oil pump several times.