[s-cars] Fuel Rail Leak

[Kirby Smith]

If mine started leaking, and I had to wait so long for a replacement
part, I'd initiate the process I prepared for when waiting for the fuel
line to leak on my 95 S6 (it hasn't yet, but I've wrapped the critical
area with heat shield material).

a) there are Aeroquip type fittings (available from Summit I think) that
can connect to -5 tubing (close to Audi metric line +/- a few
thousanths) and provide a -6 interface to -6 braided hose.  the other
end of the hose would go to a standard banjo fitting at the fuel
filter.  I haven't tried this yet, but planned to if there was a leak in
the fuel hose at the usual place.  I think it could be done at the fuel
rail tubing if the chroming doesn't make it too hard.

b) Better would be to remove the fuel rail, mill off whatever braised
tubing was in the way, and tap the front end for a banjo fitting as in
the earlier engines.  This might require welding a boss on there; I
haven't looked at it carefully enough.  Then a longer section of braided
-6 hose would be used to get from the fuel rail to the fuel filter.  Or,
perhaps, a wreck engine could supply the older fuel rail.  I have no
idea if an older one would be fully compatible with the S6 AAN engine
configuration.

Obviously, these approaches would require considerable time, but perhaps
less than waiting on Audi.  They would, of course, transfer certain
legal liabilities of Audi to the experimenter.

kirby

"Varon H. Fugman" wrote:
>
> I too had the leak where the fuel supply line connects at the firewall.  I
> just replaced my fuel rail last Saturday, so I'll throw in my $0.02 as
> well...
>
> 1. It appears that the fuel rail and fuel supply line are separate parts
> with a banjo bolt at the front end of the fuel rail (as shown in Bently) on
> the '92-'94 S4, but on the '95-'97 S6 it is a single one-piece assembly.
>
> 2. Mine leaked two years ago in December on an 8 degree F day.  There was a
> steady drip drip drip of fuel from the connection.  Wish I had thought to
> document it with the camcorder!  I had smelled gas under the hood the
> previous April on two occasions, but never localized it, only determined it
> wasn't from the turbo side of the engine.
>
> 3. Replacement fuel rail assembly took 12 weeks to arrive from Germany.  I
> suspect some German craftsman somewhere has to assemble all the parts on a
> jig and braze the whole thing together.
>
> 4. After a week, I experimentally drove the car again.  No leak.  Ended up
> putting the car back into service.  No more leak again.  For two years,
> including cold temperatures.
>
> 5. The fitting where I had the leak swivels where the rubber hose is crimped
> onto the metal fitting (the part with female threads.)  Sounds like Mark's.
> I don't think this crimped connection is supposed to swivel.  None of the
> other similar crimped connections swivel.  The crimped connection on my new
> fuel rail assembly does not swivel.
>
> 6. All the connections on the *new* fuel rail assembly are double-crimped.
> They look similar to the double-crimped connections by the fuel filter on
> the piece that was replaced under the recall.  I suspect they became aware
> of problems with the single crimped connections and went to the double crimp
> as a solution.
>
> 7. If I had known the new $300+ fuel rail was going to take 3 months to
> arrive (I was told 1 week), I would have taken the old one to a shop that
> makes up hydraulic hoses to see what they could do (i.e. maybe crimp on a
> new end.)  However, I would not try any home-brew solutions involving
> clamps... this is a high-pressure fuel system!
>
> 8. I shouldn't have waited two years to replace my fuel rail, but since it
> wasn't leaking any more the immediate motivation was gone.  Took another
> leak back at the tank to force me into working on the fuel system.
> Replacing the fuel rail assembly itself is a pretty easy job.
>
> 9. Bill, having the recall done recently could have caused, or at least
> precipitated the leak if the tech wasn't careful to hold that side still
> while turning the part with the male threads on the fuel supply line at the
> firewall.  In other words, there is a good chance that while
> disconnecting/reconnecting the line some swiveling action happened at the
> crimp, leading to the leak.  My leak happened 3 months after some major
> engine work.  If it hadn't been for the fuel smell earlier, I would have
> blamed this for my leak.
>
> 10. I am thinking of writing to AoA to see if they will reimburse me for my
> fuel rail (and sender assembly, but that is a different fuel leak!)  Not
> sure if it is worth my time to follow up with them or not.  Any thoughts?
>
> 11. I am wondering if I should file a report with NHTSA on my two fuel
> leaks.  I don't want to punish Audi (and thus discourage them from bringing
> special cars to the US), but I don't want anyone to get burned (either
> figuratively or literally.)  Too bad AoA isn't being more proactive about
> this.  I know of at least 4 types of fuel leaks on these cars: [a.] near
> turbo, line replaced by recall, [b.] fuel rail supply line leak at firewall,
> [c.] fuel line under the car at the rubber bushings, and [d.] fuel sender
> assembly at the top of the tank.
>
> OK, that ended up being more like $0.11 worth.  Sorry so much, just wanted
> to make sure I am sharing anything that will help anyone!
>
> Varon
> '95 urS6 w/new fuel rail, filter, and sender assembly
>
> _______________________________________________
> S-CAR-List mailing list
> S-CAR-List at audifans.com
> http://www.audifans.com/mailman/listinfo/s-car-list