I know you got rid of your tank but so others will know that happen to come upon this thread.. I have tried to make this so simple and easy to follow for the new people.
Old tanks you can try this if second wash fails but you might have to replace O-rings
ON NEW TANKS
Problem- There is a leak at the middle of the 510 connector or out the 510 connector holes, it doesn't look like the tank is leaking on the outside.
There is air getting in the tank so it's not sealed properly at the O-rings.
1. You need to pour your juice back into your container.
2. Slide the Cartomizer out
3. Remove both end caps
(Try to be easy doing this as you do not want to gouge the plastic cap or the rubber O-rings, I used a blunt toothpick)
4. Remove the outer O-rings from the top and bottom caps
5. Remove the inner O-rings from the top and bottom caps
6. Wash the caps I ran fingernail (toothpick works too) around the o-ring grooves (clear out mfg pieces from milling), O-rings, tube with warm water and a rag (Do not dry)
(Do not get water in the Center of the Cartomizer where the filler is) See bottom note if you got water in it.
7. Wash with a rag the outside of the cartomizer tube (Do not dry)
IMPORTANT - When putting everything back together run under warm water again DO NOT DRY. This helps to create a seal
8. Take the cap and O-rings get it wet and assemble together (I noticed this on an O-ring or 2 there is a line on the O-ring that was twisted I don't know if this made a difference or not but I made sure it was straight and not twisted on reassembly)
9. Place polycarb Tube on cap
10.Repeat Step 8 for other cap
11. Insert Cartomizer
12. Fill tank with your juice about 1/4" above the hole in the cartomizer
13. Close tank and put on drip tip (Wipe the DCCT and 510 connector off)
14. Put tank on PV
15. Stand the Pv with tank upright and let sit (you can also try and just prop the tank upright on something, I preferred to put it back on my mod since I put it on my desk and looked at it often)
20. About 5,10,15,30 min marks check bottom of tank for leaks out the cartomizer side holes on 510 connector if not then add a little more juice and recheck again on 5 min increments. If there is pool of juice then it's still leaking GOTO STEP 1
If you made it this far your done tanks sealed and you really shouldn't have to do this again ever.
If you have questions about it doing this then just Pm me I'll try to answer them
(NOTE: Water in Cartomizer, Just blow hard in the drip tip end this will clear out the channel, your juice might be a little diluted. You can keep blowing and run warm water in it again until it's clean of all juice then let it sit out to dry and use another cartomizer)