Smoke Testing

Smoke testing should be used to identify a leak only when instructed by Technical Assistance. Refer to the manufacturer's instructions for information regarding using the smoke test equipment. Smoke may be introduced into the fuel system through the purge hose, the fuel filler neck or the DMTL filter housing. When introducing smoke through the DMTL filter housing, use the manufacturer approved diagnostic system to perform routine - Evaporative System Diagnostic Check - to make sure that the DMTL changeover valve is energized and the DMTL pump is running.