There can be several causes for liquid leaks, most of which occur through the airflow. So you need to identify the area of the leak. If it's coming from the glass, it's a poorly fitted or faulty seal, which needs to be replaced or refitted. If the leak is coming through the air flow, the problem is in the coil: you will need to check that there are seals on the coil and retighten it. If the leaks continue, your coil may be at the end of its life and should be replaced. After all these operations, if the leaks are still present, you'll need to check that your e-liquid is suitable for your equipment. Some coil can only withstand high rates of VG (the glycerine is very thick), and if the e-liquid is too fluid (high levels of PG) the leaks will be constant.