About 4 weeks ago I noticed a half flat foot at the front right, ok can happen tires unscrewed for screws, nails or other obvious damage and found nothing. Ok the tire pumped up, mounted and observed over the week, he lost about 1bar in the week. Since we wanted 2 weeks later by car on vacation I am then to the local tyre dealer to have the tire checked, in the water basin then a leaky valve insert fes That’s what I thought, but the next day the tire was flat again, it was… I was pumped up and again and no one had an explanation but very hard. Wheel down into the water pool brought me along and nothing to see no bubbles. At my request a new rubber valve was inserted and then there was also peace, I thought. 2 weeks later, Wednesday evening, 2 days before departure in the holiday resort, refueled and n atürlich air and everything else controlled, everything ok, next morning front right tire flat, shei… can’t be???? Tires with on-board compressor pumped up and left overnight would be flat the next morning (departure day) then I would have visited workshop but everything was ok. On the way controlled several times, but everything ok. Can the tire species give me perhaps an explanation for this, I have to work there maybe again, it can not be normal, od tire factory Hankook Ventus Prime 3 205 50 r16