OEM GMC Yukon XL 1500 Secondary Air Injection Check Valve

GMC Yukon XL 1500 Secondary Air Injection Check Valve Parts and Q&A

• Check Valve
  12556070
  Q: How to replace the Secondary Air Injection Check Valve/Pipe on Bank 1 on GMC Yukon XL 1500?

  A:

  The first step for replacing the bank 1 Secondary Air Injection Check Valve/pipe involves removing its clamp then disconnecting the Air Hose. The replacement process begins by six steps. The technician must first remove the check valve from the left air pipe before taking out the air pipe from the Exhaust Manifold. The check valve replacement requires a valve operation inspection through a Vacuum Pump connection to the check valve nipple (AIR pump side) with 10 inches hg pressure and 5-second vacuum decay observation for decision-making. The check valve installation requires the attachment to the air pipe with 23 n.m (17 lb ft) torque followed by the air pipe hook-up to the Exhaust Manifold using 20 n.m (15 lb ft) torque. Last step involves attaching the hose from the check valve and tightening it with the provided clamp.