Aspirator Assisted Systems

1. Connect a vacuum gauge to point "A", or point "B" on Buick and Oldsmobile with 5.0L V8 engine. See Fig 1. Run engine in closed loop mode at 2500 RPM. Vacuum gauge should show a minimum reading of 5 in. Hg. If reading is low, remove and clean aspirator with mineral spirits.
2. Check AIR pump for output. Plug the 2-port check valve at port "B". Blow low pressure air into hose at point "C". Air should exit freely from point "A". Reverse the procedure so that point "A" is plugged and air will exit freely from point "B".
3. If air does not exit freely from both directions, clean or replace 3-port check valve. Plug air flow at point "B" and blow air into point "A". Then plug point "A" and blow into point "B". No air should exit from point "C".

Fig 1: Typical Aspirator Assisted Vacuum System Vacuum gauge should show a minimum of 5 in. Hg.