[W126 Coupe] fuel pump buzzing

[Dick Spellman]

The buzz is an indication of the pump wearing out.  Should go for a while
without affecting pressure.  I have just replaced them in the past once the
buzz became constant and heard while driving.

This past week while meeting with Mike Ramay in Las Vegas he mentioned that
removal of the pump and running diesel fuel through it (I think with pump
reversed) dissolved much of the crud and gave some additional service life.
You might want to ask him for additional details.

\Dick