07 gas tank problem

[jr_gray]

I have an 07 gs500f that the gas tank keeps going under a vacuum.  When this happens obviously it will not allow
gas to flow. I have taken cap apart thinking there has to be some type of vent to allow air in, but cannot figure it out. Am I looking in the wrong place for such a vent? I did follow the sticky about this problem however may cap doesn't seem to be the same.
thanks for any input.