Posted by katorpus (jrb@…>)
It seems like you could take this an extra step further with little
cost…
1 quarter turn on-off fuel valve.
1 3-way fuel valve (in this case, you’re plumbing it with 2 inlets
and one outlet…selecting the inlet you want to use)
tees, flare fittings & minor lengths of fuel line.
1 automotive-type electric fuel pump (cheap at auto parts store). Get
the one sized for a diesel engine…flow rates vary. Don’t use a high
flow pump that over-runs the filter-rate design of the filters, or
you might just blow the guts out of the elements in them.
1 spare 12v circuit on your electric panel and a cutoff switch near
the pump.
Install a Tee into your original fuel line upstream of the filter,
followed by the on-off valve and the new pump, then the 3 way valve.
The second inlet of the 3 way is installed in-line on the original
fuel line and downstream of the first tee, but still upstream of the
filter.
What you’re doing here is creating the ability to bypass the original
flow, not diverting all of it through the electic pump.
With engine off, turn the 3 way to pick up from the electric pump,
make sure the other valve is closed (to prevent fuel in the pickup
line from draining back into the tank), replace filter, turn on
breaker, open the on-off valve while flipping switch to turn on
electric pump, sit back and watch.
After filter is purged of air, continue to run pump long enough to
purge air from injectors (the extra fuel will return to your tank via
the fuel return line that the engine uses in normal operation), then
turn off electric pump and switch the 3 way back to the un-pumped
pickup line mode, and close the on-off valve.
Unless the air won’t purge from the filter, you wouldn’t even open
the bleed valves on the filter.
If the mechanical fuel pump on the engine goes south, you now have a
backup (as long as you have juice to run it).
You could get really fancy and plumb the “outflow” from the filter to
a 3 way valve with the second outlet tee-d into the fuel return line
(downstream of the engine, upstream of the tank and thus bypassing
the engine)
You would then be able to “quit” pumping with the
electric pump once the filter was purged (since you never pushed air
to the injectors) and you’d have an onboard fuel-polishing
arrangement.
Switch this valve from “normal operation” position before switching
filters and you’ll get zero air influx or backflow of fuel in the
line that feeds the engine’s fuel pump.
I wouldn’t “polish the fuel” by continuously running the electric
pump without having it go directly to the return line, as this might
have bad results (from continued use) on the injector system and/or
mechanical pump.
Note that your electric pump will be pumping unfiltered fuel. If
there’s so much gunk in your tank that this creates a problem, you’d
probably be gumming up your new filters immediately anyway.
Nothing in this arrangement precludes you from being able to change
your filters in the “normal” old-fashioned way, and the electric pump
can be totally isolated from the system by the use of the two valves.
— In FreedomOwnersGroup@yahoogroups.com, “rick_simonds”
<rick_simonds@…> wrote:
— In FreedomOwnersGroup@yahoogroups.com, “Rick Higgens”
<higgens@> wrote:
Hi all, I am getting ready to change out the stock fuel filter
for a
Racor and because of space in my F30 am using the smaller unit
(that
doesn’t have a built in primer plunger). I was wondering if
anyone
has ever installed one of those bulb style primers inline ahead
of
the
filter to fill it up after filter changes? I’ve been looking at
them
and can’t see where they say they can’t be used for diesel (nor
does
it say it’s okay). They come in various fuel line sizes and it
seems
like a natural solution to manually filling up the filter bowl.
I have an outboard-style squeeze bulb upstream of my first filter.
It
works really well for filling the filter and purging the air out of
the lines. It’s been there for over 10 years without the slightest
bit of a problem.
Also, over time, I managed to strip out the threads on the filter
housing that hold the bleed screws. I ended up drilling them out
larger, tapping them and replacing them with small brass T handle
valves, like what are used to supply water to the icemaker in a
freezer. The valves have a short length of plastic hose hooked to
them. When needed, I put the hose in a empty cup, open the valves,
squeeze the bulb, then close the valves. The purged fuel in the cup
gets poured back in the fuel tank.
No tools needed and it takes about a minute.
Rick
Tallahassee