Fuel Tank Pressure Release Valve: Testing and Inspection

1. Remove the Fuel Fill Cap.

Vacuum Pressure Gauge / T-fitting:

2. Remove Vapor Line from the Fuel Tank and connect to T-fitting from Vacuum Gauge and Vacuum Pump.
3. Apply vacuum slowly and continuously while watching the Gauge.

Vacuum should stabilize momentarily at 5 - 15 mmHg, (0.2 - 0.6 in.Hg).
- If vacuum stabilizes (Valve opens) below 5 mmHg (0.2 in.Hg) or above 15 mmHg (0.6 in.Hg), install a new Valve and retest.

Vacuum Pressure Gauge / Pressure Side:

4. Move Vacuum Pump Hose from Vacuum to Pressure Fitting, and move Vacuum Gauge Hose from Vacuum to pressure side.
5. Slowly pressurize the Vapor Line while watching the Gauge.

Pressure should stabilize at 10 - 35 mmHg (0.4 - 1.4 in.Hg).
- If pressure momentarily stabilizes (Valve opens) at 10 - 35 mmHg (0.4 - 1 .4 in.Hg), the Valve is OK.
- If pressure stabilizes below 10 mmHg (0.4 in.Hg) or above 35 mmHg (1.4 in.Hg), install a new Valve and retest.