Hi guys, I know there are many topics with cooling system to ventilate, but they don’t help me any more. I have the problem that I had to change the temperature sensor after switching to a new Koso Tacho. As a result, air came into my circulation. This led to the thermoswitch still not turning on the fan at over 90 degrees. I got the system vented via the drain screw on the water pump. Exactly at 93 degrees the fan always went on and the mo I was surprised to see why it only happened from 93 degrees. On the Internet, the cooler lid was advised to open and ventilate, but that caused a lot of fluid to swip out. When I turned off the engine afterwards, the cooler sucked the liquid out of the balance tank and emptied the container and then pulled in the air. Now the fan jumps down even to 88 degrees. I tried again to vent through the drain screw, but it does not lead to success. Feels at the thermoswitch this does not reach as high temperature as e.g. the drain screw. What makes me stubborn is that it only drips when the screw is opened, it doesn’t flow. According to forum entries it has to flow there always evenly. And can it be that the cooler is now not completely full and has air above that the circulation now has How should I proceed best? Stand up right now and I am grateful for every tip. And yes, I’m not a professional. I would like to have my quad done in a workshop, but everyone rejected it because I didn’t buy it from them. VG