"Ken Coit" wrote in message .com...
Garry,

Looking at the Perkins 4.108M handbook published in 1979, it appears that
the "fuel oil leakoff pipe" connects the "atomizers" together and then runs
to the tank. This would put it after the fuel injection pump.

Looks like you need some more plumbing....

Good luck,

Ken
S/V Parfait
Raleigh, NC


"Garry Elmer" wrote in message
...
Greetings!
I was wondering if anyone knew the mechanism with which the Perkins 108-4
returns un-used fuel to the tank?

I installed a new electric fuel pump in our system and set the supply
valve
to one tank and the return valve to the other, trying to transfer fuel and
polish it at the same time, with the diesel off. I did not notice any
fuel
being transferred so I assumed that the mechanical lift pump was in the
way.

I replaced the fuel filter on the diesel yesterday and while bleeding the
system at the low pressure inlet to the high pressure pump, had plenty of
fuel flow from the electric pump. Much more than expected from the looks
of
my bilge.

Where does the return fuel line "pick off"? Is there a pressure relief
valve associated with it? Should I be able to transfer fuel by using the
electric fuel pump with the diesel off?


Thanks!

Garry
Mystic, CT
s/v ChrisDaLyn
1983 IRWIN 38 CC
http://www.99main.com/~elmergw/





Gary, the route your fuel takes is from the tank to the
fuel injection pump via the filters and the electric and
mechanical lift pumps; if the engine is not turning, the injection
pump does not work and therefore is not sending guel to the injectors
and not pushing the excess back into the tank.... So you have no hope
of polishing your fuel unless you install an additional fuel line
(with a stop cock) before the injection [ump
john