Caprice V8-265 4.3L VIN W MFI (1995)
Evaporative Check Valve: Testing and Inspection
With a hand vacuum pump, apply approximately 51 kPa (15" Hg) to the control vacuum tube. After ten seconds, there should be at least 17 kPa (5" Hg)
vacuum remaining. Be sure the hand vacuum pump being used does not have an internal leak and the hose connections to control vacuum tube and pump
are secure. If after 10 seconds there is less than 17 kPa (5" Hg) vacuum, the valve must be replaced.
With 51 kPa (15" Hg) vacuum still applied to the control vacuum tube, attach a short piece of hose to the valve's tank tube side. Blow into the tube. You
should feel the air pass through the valve. If air does not pass through, the valve must be replaced.
