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Home >> Cadillac >> 2007 >> Escalade EXT >> Repair and Diagnosis >> External Pages >> Different car >> Section 35 (Engine Control System - System & Component Testing) >> Air Induction Systems >> Auxiliary Intake Air System >> Vacuum Check Valve Inspection
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Vacuum Check Valve Inspection

WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Numbers in parenthesis in the test steps correspond to those in figure. See Fig 1 .
  1. Remove the vacuum check valve (1) from the auxiliary intake air system. See Fig 1 .
  2. Connect Hand Vacuum Pump (J 23738-A), or equivalent, to the intake manifold side of the vacuum check valve. See Fig 2 .
  3. Attempt to apply a vacuum of 10 in. Hg to the vacuum check valve.
  4. The check valve should NOT hold vacuum pressure.
  5. Disconnect the vacuum pump from the check valve.
  6. Connect the hand vacuum pump to the other side of the check valve.
  7. Apply a vacuum of 10 in. Hg to the vacuum check valve.
  8. The check valve SHOULD hold vacuum pressure.
  9. Replace the vacuum check valve if the valve failed either of the previous tests.
  10. Install the vacuum check valve (1).
  11. Ensure check valve (1) is installed with the side that holds vacuum toward the intake air control solenoid (4). See Fig 1 .
Fig 1: Identifying Vacuum Check Valve
G00180744Courtesy of GENERAL MOTORS CORP.
Fig 2: Testing Vacuum Check Valve
G00180745Courtesy of GENERAL MOTORS CORP.
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