Check By-Pass Selector Valve

Disconnect push-connect fittings from fuel tank selector valve for affected tank. Install push-connect fitting adapters between fuel lines and selector valve. See Fig 2 and Figure .

Fig 1: Fuel Tank/Selector Valve Adapter (2 Required)
Courtesy of FORD MOTOR CO.

Fig 2: Identifying Fuel Tank/Selector Valve Connector Locations
Courtesy of FORD MOTOR CO.
Run engine at 3000 RPM for 2-3 minutes to clear any air ingested during adapter installation. Run engine an additional 2 minutes and observe transparent fuel lines in adapters.
If bubbles are not present in either adapter, air leak is between fuel tank selector valve and fuel filter/water separator. Repair or replace lines and connectors as necessary. Repeat procedures in the CHECK FOR BUBBLES OR FOAM test.
If bubbles are present in both adapters, air leak is between fuel tank and selector valve. Repair or replace fuel lines or connectors as necessary. Repeat CHECK FOR BUBBLES OR FOAM test.
If bubbles are present in the selector valve outlet adapter only, replace fuel tank selector valve and repeat procedures in the CHECK FOR BUBBLES OR FOAM test.