This sounds like the cart, not the screwdriver itself. If you are using original filler, after a while leaks become more common. You are getting
juice in your mouth because the
juice is going into the carts side vents. Look at the cart and on the sides are two "whistle" vent holes for air flow. Juice is getting into those. This can mean your cart is not holding the juice well, so I would either clean the filling and repack it, or look into a cart mod, like blue foam or the ZFM mod. The stock filler is notorious for being good for a few days, maybe, and then being problematic.
Another thing that could be causing this is your atty is not getting hot enough to vaporize the juice effectively. Attys can grow weak, and there is no set lifetime for them. If you have a multimeter, you can check the resistance of the atty, by putting the black lead to the center hole on the threaded end, and the red lead to the outside of the threads. If you read much more than 2.5 ohms, your atty is too weak, and you should either get it replaced or just try a new one. Clean the current one. Bad contacts can do all this too.
