Why does the transmission vent of the Mercedes-Benz Vito 119 leak oil?

[LeMelanie]

Mercedes-Benz Vito 119 transmission vent oil leakage may be due to overfilling of oil. The origin of Mercedes-Benz: Mercedes-Benz is a world-renowned luxury car brand. In January 1886, Karl Benz invented the world's first three-wheeled car and obtained a patent, earning him the title of "the inventor of the automobile." At the same time, Gottlieb Daimler, another founder of Mercedes-Benz, invented the world's first four-wheeled car. From then on, the world changed. In June 1926, Daimler and Benz merged to form Daimler-Benz AG. The influence of Mercedes-Benz: As the inventor of the automobile, Mercedes-Benz has a glorious history of 132 years, and the three-pointed star emblem is widely distributed across China. In 2017, China became the first single market in the world where Mercedes-Benz surpassed the 600,000 annual sales milestone.

[SanKiara]

I've repaired many Mercedes-Benz vehicles, and transmission vent hole oil leaks are quite common. I've encountered this issue several times on the Vito 119. The main cause is usually aging or damaged seals, especially after a few years of use when the rubber material hardens and fails due to heat and vibration, allowing oil to seep from the vent hole. Another factor is excessive internal transmission pressure, such as when driving in hot weather or on long trips where increased oil temperature raises pressure, leading to leaks. Sometimes, a clogged vent hole can also cause similar issues, as accumulated dust blocks ventilation and causes oil to leak. I recommend regularly checking the transmission fluid level and the vent hole area for any oil stains or dirt. If you notice a leak, don't delay repairs—simply replacing the seal is often sufficient. Regular transmission fluid maintenance and vent hole cleaning can effectively prevent these issues. Ignoring oil leaks can accelerate transmission wear, leading to more expensive repairs, so early detection brings peace of mind.

[EllianaLynn]

As a Mercedes-Benz Vito owner, I once experienced oil leakage from the vent hole, which was quite concerning. Later inspection revealed it was caused by a blocked vent hole. Since I mostly drive short distances in the city, the frequent oil temperature changes led to internal pressure buildup, and the vent hole got clogged with dust, resulting in oil leakage. Possible causes include aging of the sealing ring, as rubber materials can become brittle and crack over time. Additionally, driving habits like frequent rapid acceleration and hard braking can increase transmission pressure, leading to seepage. It's advisable to remind the mechanic during each service to focus on cleaning the vent hole area. You can also check for oil stains yourself. If the oil traces are minor, you can monitor the situation for a few days, but it's best not to attempt repairs yourself to avoid damaging parts. Safety first—if the leakage is severe, immediately visit the dealership for inspection and part replacement. Gentle driving to avoid excessive vibrations can help reduce such issues. The Vito is reliable in quality, but maintenance should not be neglected.

[LunaLee]

I usually enjoy studying mechanics. Transmission vent leaks are mostly caused by seal failure or design issues. Specifically, on the Mercedes-Benz Vito 119, the vent's function is to release internal pressure. If the sealing ring ages, cracks, or becomes clogged, oil may seep out. Common causes include material fatigue of the rubber ring after prolonged use, excessive oil pressure, or leaks due to contraction from temperature variations. It's recommended to regularly check the transmission oil condition and look for oil stains near the vent, replacing the rubber ring promptly if issues are found. Gentle driving habits can help reduce pressure fluctuations and extend component lifespan.