Aeromotive 11108 - MARINE A1000 FUEL PUMP - Manual (Page 7)

Any filter element not meeting these criteria may fail to flow the full volume of the pump, resulting in
both vehicle drivability and pump reliability problems. Aeromotive fuel pumps are engineered to be
efficient, and can create both high outlet pressure and high inlet vacuum. The boiling temperature of
any liquid varies with pressure. For example, the engine’ cooling system is purposely designed to
pressurize the coolant in order to raise the boiling point. So how does this apply to fuel delivery?
When a fuel pump has to pull through a restriction to get fuel from the tank a vacuum develops which
lowers the fuel’s boiling temperature, cavitating the fuel and turning it from liquid into vapor. Bottom
line: Inlet restrictions create vacuum, which causes cavitation, which in turn causes vapor-lock and
fuel pump damage. Of course, drivability problems and even engine damage can result! Lesson:
Don’t combine high flow, efficient fuel pumps with poor flowing inlet filters. Don’t use fuel lines
smaller than the pump ports. Don’t use fuel tank pick-ups or tank outlets smaller than the line.
What about a fine filter? They are also necessary, but must be installed on the outlet side of your
Aeromotive fuel pump, never on the inlet. Options include the Aeromotive 10-micron (replaceable
element) fabric filter assemblies P/N #12301 and P/N #12310, and the new, high-flow 40-micron
(cleanable element) stainless steel filter assembly P/N #12335. Given the alcohol content found in
today’s pump gas, it is now necessary to frequently monitor and service any downstream fuel filters in
use. Because they cannot be cleaned, keep a spare 10-micron element on hand for immediate service
to eliminate engine fuel starvation and drivability problems when they become heavy clogged.