Howdy all,
In reference to the thread on gas tanks and fuel pump whining, about a
year ago I elaborated on what I discovered when I yanked my gas tank and
found what appeared to be small rust particles in the fuel filter
element.  I removed the tank and replaced all my tank seals, gaskets,
and expansion tank seals and fuel lines.

The expansion tank seals are located on top of the expansion tank in the
wheel well.  Now if the seals are bad and you drive in wet conditions
some debris and water could be thrown from the spinning wheels and
enter  through the bad seal into the expansion tank and then from the
bottom of the expansion tank into the gas tank.  Not good.

On the gas tank itself, there is a small circular low section on the
bottom which on the inside is an isolated chamber where all dirt, water
and whatever will eventually settle.  The fuel outlet is located in this
chamber.  While I had my tank out I cleaned mine at a car wash with the
high pressure jet.  Lots of stuff came out.  I then had to get a bicycle
and pump air into the tank via the fuel outlet to clear the line.  I
could not blow it clean.

I attempted an ASCII drawings below to show the isolated chamber.  The
fuel enters the chamber through the center hole.  The exterior of the
tank above the bottom is not shown.

                                                 //========== to pump =>
                            center hole         //
bottom => ----+------------------| |-----------//--------+--------
of tank        \                              //        /    small
                \   gas line intake >========//        / <===isolated
                 \____________________________________/      chamber

I still have the whinny fuel pump.  I replace filters and the whine
restarts shortly thereafter.  The gas tank shop suggested welding in a
new outlet above that little chamber.  maybe that is the next best
option unless I find a new tank.

I carry extra filters and can change them in about 15 minutes now but
that's not the real problem.  I think it is the restricted flow from the
tank depriving adequate amounts of gas to the fuel pump causing it to
whine.  This is a symptom of a plugged filter.

IMHO, FWIW, & HIH
CU L8R
Ken
82westy
slc, ut