Diesel Data: Automotive Repair

Vacuum/Thermostatic Bowl Vent Valve


1. With valve temperature at or above 120°F, ensure that air flows between carburetor port and canister port when no vacuum is applied to vacuum signal nipple.
2. With valve temperature at or above 120°F, apply vacuum to vacuum signal nipple and ensure that air does not flow between carburetor port and canister port.
3. With valve temperature at or below 90°F, ensure that there is no or very little air flow between carburetor port and canister port, whether or not vacuum is applied to vacuum signal nipple.