Hello all.

I've just finished a subaru transplant. In the process of doing
everything else, I replaced all of the lines on top of the tank and to
the fuel pump.

Now I've got the engine in and running, but the fuel pump seems to draw
in air from somewhere. It makes sounds like it is cavitating which it
did not do before. Currently I haven't figured it out, but I am
guessing air is coming in at the little plastic fuel filter unless it
is coming from the tank.  I've verified that my pump is ok. If I stick
a 1/2" hose from the pump directly to a gas can, it works like a charm
but it pulls it out (and back into the gas tank) so fast I can only run
it for 30 seconds.

Question 1)
Is there a way that the source of the air could be the line coming from
the fuel tank (with 4 gallons in the tank)? The van in sitting level.

Question 2)
What is the best way to stop air from getting sucked in? I've tried
clamps, double clamps and a bunch of other things. I spent hours trying
to figure this out and still am not any closer.

I've considered it might be a crack in the fuel filter. I can't blow
air through it though. I noticed that the plastic is very pliable and
the hose clamp can cause deformation of the nipple, causing air to be
drawn in. I tried for a long time to figure it out and can't. I blew
air back into the tank to see if there was a blockage....nope.

So any ideas of how to best troubleshoot/fix this? Sometimes it's the
little things that get me!!!!

Thanks!
Aaron