Aerostar 2WD V6-245 4.0L (1990)
Fuel Return Line: Description and Operation
Hairpin Clip Connector
FUEL LINES AND CONNECTORS
Fuel injection systems often use special kinds of fittings to ensure leakproof connections. Some high-pressure fittings use O-ring seals instead of the
traditional flare connections. The O-rings are made of special materials that can withstand contact with gasoline and alcohol-blend fuels. Whenever you
replace one of these O-rings, you must use a new part specifically designed for fuel system service. The O-rings used in air conditioning systems are not
satisfactory.
Ford uses nylon fuel tubing with several unique push-connect fittings. Special barbed connectors are required to join sections of nylon tubing together.
Connectors that join nylon to steel tubing also have barbed ends for the nylon lines, but they use O-rings to seal the steel line. Ford uses two kinds of
retainer clips on these connectors. Fittings for 5/16 and 3/8 inch lines have hairpin clips. Fittings for 1/4 inch lines have duckbill clips.
Fuel Supply Manifold Assembly
FUEL SUPPLY MANIFOLD
The fuel supply manifold assembly delivers high pressure from the vehicle fuel supply line to the six fuel injectors. The assembly consists of a preformed
tube for fuel supply and one for fuel return. The fuel manifold assembly has six injector connectors, a mounting flange for the fuel pressure regulator,
and mounting attachments which locate the fuel manifold assembly and provide fuel injector retention. The manifold also is equipped with a fuel
pressure relief valve on the fuel supply tube.
