Fuel pump - lessons learned

[Steve Manning <stephenm@ix.netcom.com>]

With my current fuel pump problems, I've gotten really good at removing and
installing the pump.  I thought I'd share some things I've learned.  This
applies to the in-tank pump in my 1990 200tqw (and equivalent) cars:

- My 1990 actually has the fuel pump setup from the 1991 3B-engined cars.
Maybe this was a running change, but check before you buy parts (and some
1990-up's have been converted to the Piersburg pump, which also has a
different support assembly).
- The top of the fuel pump is o-ringed onto the support assembly.  Most
probably, after years in the tank, it will have become hard and brittle and
break when you take out the pump (like mine did).  Do yourself a favor and
get a new one before starting - Audi part #N90464402 (dealer-only).  It's
about USD$1.50.
- The Bosch fuel pump has a 'bump' on it that mates with the inside of the
support housing that goes around it.  Make sure you line that up while
installing.
- It's very easy to install the support housing around the pump into the
in-tank housing 180 degrees wrong.  It will sort of fit, but won't give
that solid 'drop down' feel when inserted.  Check both ways before installing.
- If you're careful about keeping the order & orientation of all the copper
washers in all the different connections they can be successfully re-used,
although it's always best to use new ones.
- To keep the fuel pump cool, it is best to not let the fuel level fall
below a certain level.  On my car, at just below 1/4 tank, the fuel pump
was *just* completely covered (only the damper on top was above the fuel
level).  So this is the lowest level I would go before re-fueling.
- I used latex gloves when sticking my hands into the gasoline to try to
minimize my skin absorbing it (it makes me sick).  However, keep in mind
that gasoline makes the latex soft and easy to rip.  I left chunks of the
gloves in the bottom of the fuel tank and they promptly blocked the intake
for the fuel pump.  Doh!
- Be very careful with the float assembly when you pull it out of the tank;
if you bend it slightly it will lose contact with it's little
resistor-wiper and your fuel gauge will not work.
- Keep a fire extinguisher handy!  Keep the work area ventilated!  I work
outside, with all the car doors open, and a big old fire extinguisher about
six feet away from the car.

If anyone has any questions I'll be glad to help..........SLM

Steve Manning:  stephenm@ix.netcom.com
...Physical home: Metro D.C. area, USA
.....Virtual home:  http://www.stationwagon.com