Pressure comes out when opening the fuel tank cap

Good morning,
I introduce myself, I am the new owner of a golf cabrio mk1 1.8 of 91. I understand little mechanics but I really want to learn to work on my new car.I wanted to ask you if it is normal that when you open the fuel tank cap there is a puff of pressure that sounds a lot (puffffff) with a strong smell of gasoline that lasts a few seconds. Is it normal or do I have something broken?
Thank you,
Greetings to all,

Welcome along.

Yup, completely normal. Welcome to old cars!

Ian

Welcome TEXACO, normal for a bit of pressure build up, I find it worse when going from a full tank down towards the red, twist the cap off slowly will help reduce the big rush of air….

I now try not to go below 1/4 tank as it's a metal tank and old and don't want the bits from the bottom of the tank getting into the fuel injection system…

Thank you very much for the answer, you leave me more calm. I got scared the first day I opened the fuel tank cap.
Thank you,
Good day to all,

That is a bit to much pressure, you may have a blocked breather pipe.

Was the video taken after a drive or when you filled the tank up and then low on fuel and needed to fill up?

There's a gravity valve (No. 40) which may be blocked or one of the pipes.

The gravity valve is there in case you roll the car it stop fuel coming out of the fuel tank.

https://volkswagen.7zap.com/en/rdw/golf+cabriolet/goc/1991-44/2/201-66000/

It was after a 20 minute ride with the 3/4 gas tank.

Sometimes if I take longer rides, I hear a beep in the fuel tank cap and when I open it comes out more pressure than what you saw in the video. That's why I thought I had something wrong. Could it be the valve? Disassembling the rear wheel can I access it?

Thank you very much for your responses.

Greetings