K 2500 Truck 4WD V8-6.0L VIN U (1999)
Air Injection Check Valve: Service and Repair
Bank 1
REMOVAL PROCEDURE
CAUTION: Allow the engine to cool before servicing the secondary air injection AIR system in order to reduce the chance of severe burns.
1. Remove the clamp from the check valve.
2. Disconnect the AIR hose from the check valve.
3. Remove the check valve from the left side AIR pipe.
4. Remove the left AIR pipe from the exhaust manifold.
5. Before replacing a check valve, test the valve for proper operation.
5.1. Install a vacuum pump to the nipple side of the check valve, AIR pump side.
5.2. Pump the vacuum pump to 10 inches Hg. and observe the gauge.
5.3. Replace the check valve if the vacuum bleeds down to zero within 5 seconds.
INSTALLATION PROCEDURE
NOTE: Refer to Fastener Notice in Service Precautions.
