GR Yaris Fuel tank negative pressure

[Provenjohn]

Hi,
Noticed that when I remove the fuel cap there seems to be a whoosh of vacuum built up in the tank???

 

[Ecsrobin]

Hi,
Noticed that when I remove the fuel cap there seems to be a whoosh of vacuum built up in the tank???

Standard.

 

[midlife_sportscar]

Normal on pretty much any car - tanks don't have 'open' breathers anymore, in order to avoid evaporative emissions.