Subject: pinhole leak in fuel tank of quattro - suggestions

[Mike Arman <armanmik@n-jcenter.com>]

>

>From: Tayo de Boer <tdeboer@ibm.net>
>Subject: pinhole leak in fuel tank of quattro - suggestions
>
'875kt CD quattro very small leak in the gas tank along the forward edge of
the
>tank. Since the car is a quattro getting easy access to the problem area,
>let alone removing the entire tank for repair is a real itch.


>     I've been considering two methods of repair and I'd like feedback on
>either - pro,con,other..
>in both scenarios there is a minimal amount of fuel in the tank - well
>below the seam line. My aim is to remove all the fuel if I have to.
>
>1.       the first option is to do the repair from the outside: it
>basically involves using a Dremel with various wire wheels to clean the
>seam for about 4" / 100mm in the area of the leak, this I would follow up
>with sandpaper to obtain a smooth and clean area as possible. The area
>would then be sealed with a fine mesh fiberglass strip that just covers the
>seam top and bottom, with following larger layers finishing up the job.
>It's a basic fiberglass job.The biggest drawback is that I can't see what
>I'm working on; what if I'm not successful the first time? 


Possible problems here: Grit into gas tank from the grinding, very possible
heating and sparks (kaboom!) - not encouraged!





>2.	the second option would be to seal the leak from the inside. The main
>reason for this method is that if sealed with a flexible material, the
>force of the fuel against the seam in the tank should make a permanent seal.



Gas tank sealers available from several sources (in Hemmings, for instance,
also from Eastwood), results not guarnateed, tank has to come out because
you DON'T want to get any of that glop into your fuel system . . .


Suggestion/observation: Most of the 5K Audis at the U-pull-it yards already
have the gas tank out because someone has already taken the fuel pump. The
2WD and quattro tanks should be the same, so picking one up off the ground
solves two problems - taking it out and inspecting it for cracks, flaking,
etc., out in the light where you can see it. 

Since it seems to me that you will have to pull the tank anyway (sorry), if
the 2WD and Q tanks are the same, $15 for a good tank from a U-pull-it
sounds like a better deal than patching your bad one - you don't want to do
this job twice!

Best Regards,

Mike Arman