"Air Supplier Tube" Question

[Racer X]

2 hours ago, DC871F said:

I've been chasing raw fuel vapor coming from my car, with dropping the tank, replacing hoses, pressure tested vapor tank, I them moved this flow guide valve lines. 

I wonder if a bad or clogged check valve in the flow guide valve can be the source of vapor I smell in the garage?

If it is not functioning as it should then that is a possibility.

I wonder if the springs that hold the check balls get rusted and fail? 

I doubt they are serviceable, but the function should be easy to check.