Generally speaking, if a CE3 is leaking it's due to the inner silicon seal being torn or otherwise damaged from the syringe. I have used the CE3 since they came out last fall and have only had one or two that developed leaks. In every case, I replaced the inner seal and the leak stopped.
I am going against SI instructions with this, but I use a real, 20 gauge, hypodermic to make the first puncture in that inner seal. I do use a regular blunt needle for filling always, the sharp one just to make the hole a little more cleanly. This seems to avoid, or at least lessen, the chance of tearing it with the blunt filling syringe.
They can, and I stress can, also leak is the wicks are not properly installed. They rely on the surface tension developed by the fine mesh of the wick to prevent leaking from the bottom. But even then, an extra air path is needed for a leak to occur.
In the early production runs there was a problem with the clear plastic barrel getting stress cracked during manufacturing. That problem seems to have been cleared up for some time, now. You can check for stress cracks by holding a flashlight opposite from your viewpoint and slowly rotating the CE3. Stress cracks will appear as bring line along the length of the plastic barrel.
Hope this helps you. I love CE3s and use them daily with78mm autos, despite having X2s with T3s and a couple of bigger VV and VV/VW "mods". They can't be beat for price/performance and longevity.
Just my opinion, worth what you're paying for it. Your results and mileage may vary. No warranty or guarantee is expressed or implied. Proceed at your own risk.
