53.38. Is it necessary to replace the oil filter when changing the engine oil?
UAЧи потрібно замінювати оливний фільтр під час заміни моторної оливи?
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This exam question from the Traffic Rules of Ukraine concerns not maneuvers or signs, but the technical condition of the vehicle as a component of road safety. The theoretical test checks the understanding that the driver is responsible not only for following the traffic rules on the road, but also for ensuring the proper condition of the car before departure, since a faulty or poorly maintained engine increases the risk of breakdowns while driving and dangerous situations.
In content, this question relates to the section of the Traffic Rules about the driver's duties, specifically to point 2.3 (subpoint "a"): before driving, it is necessary to check and ensure the technical serviceability and completeness. Although there is no direct rule in the traffic regulations requiring the filter to be replaced "every time," the logic of the exam ticket is based on the general duty to ensure serviceability through proper maintenance according to regulations: when changing the oil, the filter has already accumulated contaminants, may impair circulation, and when clogged, can switch the lubrication system to supply oil bypassing the filter (through the bypass valve), that is, essentially without filtration.
The analysis of the answers comes down to engine maintenance practice: the correct option assumes that the filter is replaced together with the oil, so that the new oil does not mix with the remnants of the old oil and wear products that remain in the filter, and to avoid operation "without filtration." Incorrect options are dangerous because they tie the decision to reusing drained oil or even allow not changing the filter at all, ignoring clogging, leftover waste, and the risk of accelerated engine wear; in the context of the theoretical exam, this contradicts the approach of "ensuring serviceability" as a basic duty of the driver.
Clause 2.3 (subclause "a")
To ensure road safety, the driver is obliged to: a) before driving, check and ensure the technical serviceability and completeness of the vehicle, as well as the correct placement and securing of the load.
This exam question does not have a direct provision in the Traffic Rules of Ukraine that establishes the obligation to replace the oil filter specifically "during each engine oil change"; such a requirement belongs to maintenance regulations (manufacturer's instructions/service standards). At the same time, it checks the understanding of the driver's duty to ensure the technical serviceability of the vehicle, which in practice is achieved by performing proper maintenance, including replacing the oil together with the oil filter.
Thus, the correct answer is "The oil filter must always be replaced after draining the engine oil," given that, according to the definition in the Traffic Rules, the driver is obliged to ensure the technical serviceability and completeness of the vehicle before driving, which implies performing proper maintenance.
When changing engine oil, it is important to understand that the lubrication system operates as a closed circuit: the oil constantly circulates through the engine, and the oil filter traps wear products, soot, and fine metal particles. Therefore, changing the oil without replacing the filter does not provide a complete result, as cleaning is just as essential as renewing the oil itself.
During operation, the filter gradually accumulates contaminants and over time loses its throughput capacity. In practice, this means that after a certain mileage it can become so clogged that normal oil circulation through the filtering element deteriorates. In such a situation, the bypass valve in the system is activated, and the oil begins to flow around the filter, that is, it reaches the engine components without being cleaned. This is essentially equivalent to operating with a faulty filtration system and directly increases engine wear.
There is another important point: even after draining the used oil, some of the old oil remains inside the filter itself. If the filter is not replaced, these residues, together with the accumulated dirt, will immediately mix with the fresh oil. As a result, the new oil loses its properties more quickly and provides less protection for the engine.
That is why, in vehicle maintenance—including for those belonging to high-responsibility categories (for example, buses)—oil replacement is considered a procedure inseparable from oil filter replacement. This logically corresponds to the requirement to maintain the technical condition of the vehicle so that it operates reliably and without premature wear.
Therefore, the correct answer is: "The oil filter must always be replaced after draining the engine oil," because the old filter contains contaminants and residues of used oil, can become clogged, and may cause the lubrication system to supply oil bypassing the filter, which accelerates engine wear.