Fuel pump vs AN fittings

I've got a Mallory 140 electric fuel pump I
want to reuse.

I bought AN fittings to use, but they only
thread in about two threads....what am I doing
wrong? Do I need to go back to brass fittings
for the pump?

I'm sure the pump will have pipe thread and you might
be trying to screw in AN thread... you need AN to pipe

they migth not be 3/8 pipe thread but 3/8 thread with a O ring


had the same problem on a barry grant 4 port regulater


I went to a local speed shop and got the rigth ones

I just looked at their web site and they state it
uses a 3/8 pipe into/ out of the pump so you need
AN to 3/8 pipe (what ever size AN you want)

Mike,

These are Russell blue AN/pipe thread adapters
to fit braided fuel line to each item.

Just wondering is there a fine/corse thread
situation here??

Phil take a run over to Home Depot with the pump and try some pipe fittings should be 3/8" NPT.

Pipe is pipe BUT I have seen pipe thread being under
size or over size, pipe thread is a tapered thread
and I have seen some of the alum fittings being over
sized (no clue why unless they want them beefier)
When I say pipe thread, I am referring to NPT which is
what Mallory stated 3/8 NPT

Phil,

I got one on the desk in front of me. They are 3/8 pipe thread unless something has changed.

I'll take a trip over to Home Depot tomorrow
and compare fittings.

I have to assume since I have aluminum AN/pipe
fittings, that the pipe part is oversize for
the 3/8" hole size.

the comp 140 takes 3/8 pipe thread the comp 250 takes -8 AN thread. pipe thread is tapered, AN is straight and requires an O ring to seal. if you have a straight AN thread you're trying to use in the pump you have the wrong fitting. what are you trying to connect the pump to? braided hose with a fitting, aluminum line with a flare or just plain hose?

I've got a fuel cell with a -10AN fitting coming
out that will have braided line to a fuel filter
with -10AN on both ends to the fuel pump and then
on to a braided line to connect to 1/2" aluminum
fuel line with -8AN on each end to the fuel regulator, then -8 to the DP carb fittings.

if i'm to understand you correctly the suction side of the pump needs to connect to a -10 and the discharge needs to connect to a -8 if that is the case you need these

3/8 pipe to -10

3/8 pipe to -8

Phil you can always hit TMR or Fast Eddies by my place for AN stuff.

Jim,

You are correct and those are the fittings I aleady bought, but the 3/8" pipe thread side
does not screw into the pump, so I will go to
Home Depot tomorrow and play around with the
brass bittings and see if I can come up with
some stuff that will work.

sometimes aluminum threads can gall when threading aluminum into aluminum and once it starts it can get pretty bad. if you have those fittings afaik you have the correct fittings. look at the threads on the fitting and in the pump to see if they're buggered up any. you can chase the pump threads with a pipe tap but if the fitting threads are galled that's another problem. it's a good idea to use teflon tape or teflon thread sealant on something like this to help keep the threads from galling. i doubt HD has anything that will work correctly i believe the angle of the flare is different.

My 3/8 NPT-AN fitting did not fit but a couple of threads into the 140 pump body. I used teflon pipe sealant and tightened it up and it has been fine. If you use 3/8 to conventional flare (Home Depot stuff), you'll need to then convert from the 45 to 37 degree flare.

The problem is that the threads on the output
side of the pump is buggered up and yes I will
need to get a pipe tape to clean it up and then
use a new aluminum AN/pipe fitting.

Thanks for all the help.