Air Injection Check Valve: Testing and Inspection

Testing The Air Check Valve:

1. Inspect the thermactor system hoses, control valve(s) tubes, and check valve(s) for leaks that may be due to back flow of exhaust gas. If traces of exhaust gas products are evident, or if holes are found, the check valve may be suspect.
2. The valves should allow free flow of air in the direction as shown. The valve(s) should check (or block) the free flow of exhaust gas in the opposite direction.
3. If air does not flow as indicated or if exhaust gas back flows opposite the direction of the arrow, replace the valve.