Two-Way Valve
- Remove fuel filler cap. Remove vapor line from fuel tank and connect a "T" fitting, vacuum/pressure pump and vacuum/pressure gauge. See Fig 1.
- Slowly apply vacuum with pump while watching gauge. Vacuum should stabilize momentarily at 0.2-0.6 in. Hg. If vacuum stabilizes (valve opens) at less than 0.2 in. Hg, or greater than 0.6 in. Hg, install new valve and retest.
- Move hose on vacuum pump from vacuum port to pressure port. Ensure vacuum/pressure gauge is set for pressure testing. Slowly pressurize vapor line while watching pressure gauge. Pressure should stabilize at 1.0-2.2 in. Hg. If pressure momentarily stabilizes (valve opens) at this specification, two-way valve is okay. If pressure stabilizes at less than 1.0 in. Hg, or greater than 2.2 in. Hg, install a new valve and retest.
Courtesy of AMERICAN HONDA MOTOR CO., INC.