Dennis Haynes wrote:

"I have been plagued with a number of new tanks that are somehow
contaminated causing the screens to get clogged up. For one customer I went
through 3 tanks and destroyed 6 pumps. Temporarily install a tee and vacuum
gauge on the pump inlet and see what you have after a drive. You'll know if
the tank is the problem."

So I bought a vacuum gauge and am ready to install.  When I drove the van
the other day the fuel pump was almost completely silent for an hour or so
of driving, then finally started buzzing.  To check on a clogged fuel tank
it seem like I'll have to leave the vacuum gauge installed between the tank
and pump as I'm driving.  I just want to verify that that's the idea.  There's
no indication that the gauge is designed for measuring liquid vacuum.  Since
I have no idea about the internals of the vacuum gauge it seems like fuel
could go into the gauge and possibly leak out.