Joe

There are actually 3 fuel pumps on the truck. The low pressure one is in the
tank. The one on the frame rail (it's pretty obvious) steps the pressure
up.

The low pressure pumps provide enough pressure to actuate the valve that
switches between tanks. It's made so that it seals in the fuel return line
to the tank that the fuel came out of. It should be obvious why that's
needed. Any leaking from one tank to another is normally not a concern, but
on your truck it might be.

<mpdsville1@yahoo.com> wrote in message
news:1139185867.563493.116130@f14g2000cwb.googlegroups.com...
> Thanks Lugnut.. I did see posts in this NG related to
> the switch valve, but i mentioned the dual tanks and
> the fact that one tank is holed on purpose. We NEVER
> use the tank switch since one is dead. If the switch valve
> is stuck, then i'm betting is stuck in the position its
> been in for the last year. I wont ignore its existence but
> my gut says its a longshot.
>