[keerocker92]

which way should air be able to flow...towards the tank or away

 

[bpann1]

Gas tank?
Oil tank?

They are designed to be sealed:laugh:

 

[JUST-IN-TIME]

it should be able to vent!
so out

 

[bpann1]

There is an outward vent check valve typicaly connected in line with the water seperator filter