that's just seems awful weird--you say "drinking" so you mean when you draw on it, fluid is coming up the tube into your mouth ?
only thing that stops that would be the big silicone cup gasket that sits at the bottom on the long chimney stem inside.(it's there?)
Are the coils new, your not rebuilding them at this time ?
1]screw new coil into base
2]fill tank (getting none in center air tube)
3]screw base w/coil onto tank w/fluid upside down
4]turn right side up allow time for wick to soak up fluid
5]vape face off
as far as 'leaking' only 3 ways to get out of the tank
1.coil - o ring on bottom or thru the wicks
2.tank - o ring on base
3.mouthpiece - silicone cup on top of coil or thru wick, up chimney into air passage into mouth
the evod is awesome (I got more than 8 of them in rotation) figure it out, you wont be sorry