Vacuum Check Valve: Testing and Inspection

1. Remove check valve from vacuum hoses.
2. Connect a vacuum gauge to EFE side of check valve and connect a vacuum pump to other side of valve,
3. Apply vacuum.
- Vacuum should be held. If not, replace check valve.

NOTE: A slow leak-down indicates the check valve is defective. If leak-down is fast, check to see if valve is installed backwards.

NOTE:
- SEE EMISSION CONTROL APPLICATION CHARTS to determine application of control switches and valves.

- Refer to the number stamped on the base of the switch or valve for calibrated switching or activation temperatures.