[A4] Split breather tube

[Jonathan]

Hi All,

I have a weird fuel leak. The symptoms are:
Absolutely nothing most of the time.
The tank will leak if I fill it right up, at full speed, until I start the 
engine and drive off, when it stops again.

From what I can find elsewhere, this is a split breather tube for the fuel 
tank.

Anyone know how to fix it?

If not, can anyone recommend a good technique for dropping the fuel tank out 
and putting back in, when I don't have many specific tools (Limited to 
generic socket set, spanners, screwdrivers etc..).

In case your worried, I generally only fill up at one petrol station, where 
I've all but mastered the technique to fill the car up without causing a fuel 
leak.

cheers

Jon