Sucking sound
 

What is this noise that sounds like it’s coming from the carb when I shut the engine off? It’s a 350 with an edelbrock performer intake and 1406 carb. I’m just putting this together, and didn’t really notice it until I got it back today from the exhaust shop. The only other thing that’s new is the check valve on the brake booster. I’ve sprayed it and the hose as well as all around the intake and carb with carb cleaner looking for a vacuum leak and didn’t find anything.

Re: Sucking sound
 

It may be a leak in the brake booster, or the grommet around the check valve. If you have a vacuum resoirvor for the A/C controls it might be that or the check valve leaking. Disconnect the brake check valve & hold your finger over the end or masking tape. Then try it. If it doesn't do iy then you know it is in the booster or grommet.
George

Re: Sucking sound
 

I found it. The vacuum tee behind the carb that I could not see or reach with my spray can without climbing up into the engine bay had somehow lost both caps.