EVAP Two Way Valve Test
Special Tools Required
- Vacuum/pressure gauge, 0-4 in.Hg 07JAZ-001000B
- Vacuum pump/gauge, 0-30 in.Hg, Snap-on YA4000A or equivalent, commercially available
- Remove the fuel fill cap.
- Disconnect the vapor line from the EVAP two way valve (A). Connect it to a T-fitting (B) from the vacuum gauge and a commercially available vacuum pump/gauge, 0-30 in.Hg, as shown.
- Apply vacuum slowly and continuously while watching the gauge.
The vacuum should stabilize momentarily at 0.8-2.1 kPa (0.2-0.6 in.Hg, 6-16 mmHg). If the vacuum stabilizes (valve opens) below 0.8 kPa (0.2 in.Hg, 6 mmHg) or above 2.1 kPa (0.6 in.Hg, 16 mmHg), install a new valve and retest.
- Move the vacuum pump hose from the vacuum fitting to the pressure fitting, and move the vacuum gauge hose from the vacuum side to the pressure side (A) as shown.
- Slowly pressurize the vapor line while watching the gauge. The pressure should stabilize momentarily above 1.0 kPa (0.3 in.Hg, 8 mmHg).
- If the pressure momentarily stabilizes (valve opens) above 1.0 kPa (0.3 in.Hg, 8 mmHg), the valve is OK.
- If the pressure stabilizes below 1.0 kPa (0.3 in.Hg, 8 mmHg), install a new valve and retest.