I use T3's as my mainstay attachment out and about. Due to the various problems with the T3 I've learned how to rebuild them. Evods and Protanks can fall prey to the same issues.
1) Keep the tank topped off above 1/3 to 1/2, especially during this hot season I've noticed the ambient temperature affects viscosity of my liquids, making them thinner, so more prone to seep and leak, most my liquids I use 50/50 or thicker, couple are 40/60 and 30/70, thinner the liquid more prone to seeping.
2) Regular cleaning of the heads. Rinsing them in warm water every refill or every other refill gets a lot of gunk out of the wicks that can make the coil not burn properly.
3) Every week a good soak in vodka or everclear for about 10 minutes, then a let dry and dry burn the coils, followed by another warm water rinse and let dry keeps the carbon and other gunk off the coils regularly.
4) Maybe look into rebuilding the heads. Presently I've switched from standard silica wick to 1, 1.5, or 2mm Ekowool, little more expensive than standard silica, but it soaks and wicks better, and holds liquid instead of seeping a lot better over silica. I can vape an entire tank down to basically the inner gasket that meets the air tube without much gurgle or pooling in the positive post of my power bases. Seen an interesting mod that uses stainless steel mesh with either ekowool sheathing or a liner of cheese cloth between the coil and mesh to prevent shorts, have heard rumor it wicks like a champ without leaks and gurgles and such.
Another alternative if you like the bottom coil design is the VapeOnly or iSmoka BCC, but where the Kanger heads have a hole in the center of the positive post, the BCC doesn't you might look into investing into these then.
If you go the rebuild methods, and wish to stay with silica, remember the default T3/Evod/Protank head uses a single wick at 2mm with 2 1mm top loose wicks. A single folded 2mm wick with no top floating wicks or a single strand 3mm with 2 1mm floating wicks kind of reduces the fault by almost 75% to nil, the channel the wicks fit in when all assembled is about 4 or 5mm, that and the stock head the coil sits parallel to the channel, I've found on rebuilds if you pull the coil further into the cup of the head closer to the bottom, also reduces the leaking and seeping, get an occasional gurgle after a little rest, but with the coil down further in the cup, it kind of boils and eventually atomizes this pool, downside to this is it creates residue and gunk quicker, thus meaning need to clean the head more often, and rinse and clean the tank every refill or every other refill. If you are at the next West Side meet I can give some pointers and such if you like.
