EVAP leak smoke test: Where to inject smoke?

I go in through the gas cap and seal the hose with rags. Not sure how that has any different danger level than anywhere else. If you use a proper smoke machine it should be fine.

It is most likely coming out the tops of the tanks so take all the access panels out of the way.

 

Use a proper Smoke Machine for two reasons. One, you can do damage to your EVAP system with two high of pressure emitted by an improper smoke machine. Two, a proper smoke machine has an indicator that tells you if you have a leak, sometimes the leak is so small you can't identify by smoke leaking out. I disconnect the hose leading to the Canister Vent valve and deliver smoke into the EVAP canister. That way it checks the whole system except the Canister Vent valve. If I have to check the Vent Valve I pump smoke into the hose leading to the valve and open/close the valve with a power probe.

 

https://www.amazon.ca/OTC-6522-LeakTamer-Diagnostic-Machine/dp/B007X74ZTK/ref=sr_1_1?ie=UTF8&qid=1489355688&sr=8-1&keywords=automotive+smoke+machine

 

I seem to hear a lot of folks telling tales about their automobile mechanic/service advisor trying to inject the smoke up their backside.
Alden

 

I used a machine from this company to check for intake and exhaust leaks on my F355

Worked well

https://redlinedetection.com/collections/technicians