Hi,
Every time I fill the fuel tank, there is a quite strong vacuum in the tank.
Anyway, it hasn't caused any problems (yet?!), but I keep wondering is this normal?
There should be some kind of valve in the cap, letting air come in, right?

My last car was V70, same company product and this never happened.

http://www.freel2.com/forum/post218203.html#218203

Great link. (If you can speak more than one language).  Past: FL2 TD4 HSE Auto
Evoque SD4 Dynamic Lux Auto
Present: Audi A3 S Line.

Glad there were pictures to support  
I'd say yes eventually there will be an issue, back in the old days mechanical pumps would fail due to inadequate stroke pressure v tank vacuum pressure. Electric pumps may endure this pressure a little longer however your breather valve in the cap can only get worse there for on a full tank drain the vacuum will increase greatly.
New cap or some delicate DIY

Both the Freelanders I have had, there was a a vacuum when opening the cap, but never had a problem with it, it is how it is designed.

Alex had mentioned this also, depends on how much of a vacuum I suppose. There must be a balance to counter the tension in the spring and there for allow air to be drawn into the tank on demand, however if it's hissing like a swan then that would be worrying.......

Thanks Alex for the link, no habla but pictures were good
Mine was really "hissing like a swan", we'll see how much this helped.
I opened fuel cap. It was surprisingly dirty, just like in those pictures.
Cleaning with cloth and air compressor.
Now that valve seems working quite ok, next time refuel shows that is there any difference.

Just wondering, because of that spring tensioned valve in the cap... when vacuum exeeds spring tension, it's short time like a vacuum cleaner.
Air flow must be quite high for a while and if it's dusty conditions, no wonder why it sucks all that that dirt in the cap
There should be a filter

Strange this - I asked the same question back in December when I changed my car from an 07 HSE to a 60 Plate HSE.
Opinion at the time being it was meant to do this - I somehow doubted this!!!
Now we seem to have a definitive answer.

Back to this once more.
Cap cleaning result was significant.
There still was vacuum in tank when I opened the cap, but maybe 1/3 compared before, or even less.
Nothing to mention, anyway

As a side-note, my last car (a Dodge Magnum) would throw engine codes and the dreaded CEL if I forgot to tighten the gas cap enough to allow for a vacuum.

Interesting thread. I have had a fairly significant hiss and suck when opening the cap since I got the car in June (it is a 60reg).

Took a look at the cap today and it is spotless, almost as if it has been replaced. Phoned local dealer and spoke to service manager. He has never heard of an issue with the caps or of a vacuum in the tank. However he would have to book it in with a risk of £150 charge if no fault found.

Seems to be disagreement on whether or not there should be any hiss or vacuum....

Aveling wrote:

Strange this - I asked the same question back in December when I changed my car from an 07 HSE to a 60 Plate HSE.
Opinion at the time being it was meant to do this

Quote:

Something wrong there, Aveling. A blocked breather can cause other problems too, like fuel starvation and even failure of the fuel tank itself (although the latter was more of a problem with steel tanks). It also makes the fuel pump work harder as it's fighting against the negative pressure in the tank.

I don't recall off-hand (can check later) but I think the breather mechanism may be in the cap itself, so you may need a new cap.

That's not quite 'meant to do it'!

Thanks for the reply. I did read all the responses and unless I've missed the point, I'm not sure either way if it is meant to do this or not. Apologies if its obvious...

Many years ago nowI had the same problem and got over it by drilling a small hole in the filler cap. Totally wrong I know but it did the trick Ex 2010 Freelander2 GS-e Diesel manual Silver owner

Chuckalicious wrote:

Thanks for the reply. I did read all the responses ...