Bronco L6-300 4.9L VIN Y 1-bbl (1983)
Vacuum Check Valve: Testing and Inspection
To check vacuum check valve, use a suitable hand held vacuum pump and apply 16 inches Hg vacuum to the check portion of valve. Maintain
vacuum. If vacuum applied remains above 15 inches Hg vacuum for approximately 10 seconds, the vacuum check valve is operating properly. If
not, replace vacuum check valve.
