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Rollover Vent Valve

  1. Remove rollover vent valve and position it horizontally. Tee in a pressure gauge to the hose normally leading to the fuel tank, plug port "C" and blow into port "A". See Fig 1 . Verify that the valve opens at .78-1.0 psi (.055-.07 kg/cm2 )
  2. Tee in pressure gauge at port "B", plug port "C" and blow into port "B". Verify that the valve opens at .14-.71 psi (.01-.05 kg/cm2 ).
  3. With the valve mounted at 90 degree angle from a horizontal position or inverted 180 degrees, attach a suitable pressure tester and gauge at port "A", apply 10 psi (.7 kg/cm2 ) and verify that pressure is held. Replace valve if necessary.
Fig 1: Rollover Vent Valve
G106276Courtesy of FORD MOTOR CO.