Testing Diaphragm-Operated Purge Valve
- Attach short hose to PCV inlet orifice (lower tube) of vapor canister. Attempt to blow through it through hose. See Fig 1 .
- Little or no air should pass into the canister. A small amount of air will pass through if canister has a constant purge hose. Using a hand-held vacuum pump, apply 15 in. Hg to control vacuum signal port.
- If diaphragm does not hold vacuum for at least 20 seconds, replace canister. If diaphragm holds vacuum, attempt to blow through PCV hose again. An increase in airflow should occur. If air does not flow, replace canister.