Testing: Ported Vacuum Valves (Evaporative Emissions System)
Vacuum Delay Valve: Testing and Inspection
Vacuum Delay Valve
Using a suitable hand held vacuum pump, apply vacuum to both sides of valve. On valve with one side black or white and the other side a different
color , vacuum should build up in one side but not the other. On valve with both side the same color, vacuum should build up on both sides before
visibly decreasing. If valve does not function in this manner, it should be replaced.
