Fuel leak from Vent tube

[BudMan]

Well, I thought I was finished with the petcock problem after getting my tank back on with a new liner and petcock.  Everything was functioning perfectly, the sky was blue, the winds were light, the Valk was running perfectly and it was a good riding day all around.  Then I filled the tank and put her away for the evening. 
This afternoon I went into the shop and smelled gas.  I was expecting to find a leak in the area of the fuel gauge or from a misaligned fuel line or something like that.  Closer investigation shows the source to be the vent line.  I drove about 11 miles from the filling station to my shop.  I routinely fill just as full at a station a lot closer to home and have never had an issue with vent line leaking before this.
I am loosing fuel at a rate of one drop every 7 seconds like clockwork.  I have opened the cap to relieve any pressure as a result of fuel expansion but it caused no change in the leak rate.
I suspect in the process of lining the tank and then unplugging the vent line after the initial tank lining attempt, the radiator shop damaged the vent tube inside the tank resulting in a leak into the tube and then down the vent line.
Has anyone ever had this problem before?  If in fact the internal vent tube is leaking in the tank, I see no way to correct the problem.  I am considering an alternative solution.  If the tube were plugged to stop the leak, obviously the tank could not breathe and fuel could not get to the carbs.  I have had a lot of old bikes and none of them had vent lines; they all vented through the cap.  Is there a way to vent the OEM cap on the Valk by making a very small hole in the area of the fuel neck? 
I’ll be on the road for the next couple of weeks so I have some time to figure this out before getting back home and working on it.  Any ideas and opinions will be greatly appreciated.

[R J]

Dis you say the radiator shop put the hole in the vent pipe in the tank?

Make em fix it free of charge...........

They have to warranty their work.......

[Pete]

Yes.

The 97 Standard had a rusty tank in the process of cleaning it out the vent tube was damaged to the point that it would actually run out about 1.5 gallons from full and stop.

I know of no way to repair the internal vent tube.

I ended up finding a new shelf stock tank ($89 + shipping on the net) with a small dent and having it repaired and repainted.

If you seal it and the vent thru the fill cap, you will probably smell gas while riding, unless you can use a fitting with an external hose to route the vapors away and down.

It might be possible to drill and insert a fitting into the filller neck or at the high point of the tank or into the cap.
you may need to baffle the fitting to prevent gas from surging into the hose on deceleration unless you put it into the cap.

Remember the way old motocross bikes vented the tank thru the cap using a hose.

Good luck Bud.

[BudMan]

Well the saga continues, but I got some great news from the shop that did the liner.  The owner told me he thinks he knows where the issue is.  He had to splice the tube back into the “tub” at the top of the tank.  The tub, as he calls it, protects the vent tube from getting fuel into it.  He could not tell for sure when repairing the tube if it sealed properly.  He will use a video scope to ensure the tube is sealed properly this time.  Even with all the problems with the tank, I couldn’t ask for a better shop to do the work.  They are committed to making it right.  I see now why EVERY dealership I called referred me to them.  He told me this was the first Valk tank he had lined and that he had “learned a lot” at my expense and would not charge me for anything that had to be done to make it right.
I’ll take them the tank later this week and post more as the situation developes.
If it ain’t one thing it’s another.