it s usually leaking from the bottom (where the electrical connections are) of the switch not just bellow the threaded part.
the lower part is made from 2 different materials and the heat cycles tend to make a leek/seep happening between them...
An experienced Airhead tech advised me to coat the area with some silicone but i also heard about the JB weld option.
Also be careful on the torque cause you need a big wrench which has a lot of leverage to tight it up...
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