Bronco L6-300 4.9L VIN Y 1-bbl (1983)
Bowl Vent Valve: Description and Operation
Carburetor Fuel Bowl Thermal Vent Valve
Fig. 10 Carburetor fuel bowl thermal vent valve
The thermal vent valve, Fig. 10, used on some vehicles, is a temperature actuated on/off valve, that is inserted in the carburetor to carbon canister vent
line. This valve is closed when the engine compartment is cold, preventing fuel tank vapors, generated when the fuel tank heats up before the engine
compartment, from being vented through the carburetor bowl.
