Make sure that the electric pump has seals and diaphragm made of EPDM
(EthylenePropylenDiamineMonomer) instead of the 'old' standard Neoprene
or Buna. EPDM is more stable and chemically compatible with diesel
fuel.

What usually breaks the mechanical lift pump diaphragm is ..... too
small of a filter set that is upstream - apply LARGER surface area
filters (easy to do if you are using 'spin-on' Racors. Less
differential pressure across the filters will allow the pump to work
'less hard'. If you are running 2uM Racors,, switch back to 10uM
Racors (and at the engine 'guard' filter) and the 'pressure
differential' will be reduced by a factor of approx. 5.




In article . com,
Frogwatch wrote:

In a thread a couple weeks ago, I talked about failure of my fuel pump
on my 28' sailboat. It is a Yanmar 2gm that has a mechanical pump that
I backed up with an electric pump to make bleeding the system easier.
I am replacing the mechanical pump but I also need to replace the
electric one. The electric one was from JC Whitney and I do not recall
the brand. However, i do remember that it was not specifically listed
as being for diesel. It is a simple diaphragm pump driven by a
selenoid. I am wondering if the diesel could have eaten away the
diaphragm. Can anyone suggest a good electric fuel pump fpr this
application? JC whitney no longer has it available and I do not trust
it anyway. However, the original owner had it installed when he bought
the boat so I assume it was supposed to be good. When it finally
failed 4 years ago after nearly 16 years, I simply bought an identical
one. Any ideas?