jonsharland Posted July 17, 2002 Share Posted July 17, 2002 I noticed yesterday when I filled up that when I broke the seal on the petrol cap that there was a Very large hiss as air either escaped or entered I am not quite sure as I wasn't paying that much attention - is this normal Jon Link to comment Share on other sites More sharing options...
I reply to every thread Posted July 17, 2002 Share Posted July 17, 2002 Yep Link to comment Share on other sites More sharing options...
ashaughnessy Posted July 17, 2002 Share Posted July 17, 2002 Seconded - it is normal. I'd be interested to know the reason though. Anthony Link to comment Share on other sites More sharing options...
Phil P Posted July 17, 2002 Share Posted July 17, 2002 This may be due to a blocked/ compromised fuel tank breather creating a partial vacuum in the tank as the fuel is used - hence the hiss when the fuel cap is removed Just a guess, but maybe worth a check... Phil Link to comment Share on other sites More sharing options...
Simos Posted July 17, 2002 Share Posted July 17, 2002 Given the weather I suspect it will be excess pressure venting rather than a partial vacuum, petrol expands and vaporises mightily in hot weather. Most cars do do it (pressure relief valve ?). I don't know if breather fitted to all 7s. Whilst on the subject the accepted wisdom is I believe to replace the factory fitted short breather hose with a longer one that loops up the roll bar and then back down again to below the tank. This stops fuel sloshing out under hard cornering or leaking out if you find yourself upside down. Edited by - simos on 17 Jul 2002 10:27:14 Link to comment Share on other sites More sharing options...
dino ferrana Posted July 17, 2002 Share Posted July 17, 2002 I think as standard Beaulieus get a vacum forming in the tank. A small hole in the cap sorts it. THis is a vague memory from a previous post try the archives? Link to comment Share on other sites More sharing options...
Alias Posted July 17, 2002 Share Posted July 17, 2002 Take the python out. Link to comment Share on other sites More sharing options...
Anthony Micallef Posted July 17, 2002 Share Posted July 17, 2002 jonsharland, its quite spooky that you should have mentioned this. The last three or four times that I have filled up my Focus its done exactly the same thing when I've released the petrol cap. The Happy 7 Ownerteeth.gifteeth.gifteeth.gif Link to comment Share on other sites More sharing options...
Phil R Posted July 18, 2002 Share Posted July 18, 2002 Hi Jon, mine was doing this before I took it to Caterham for PBC. I told them that I wanted it looking at and was told "Lots of cars do that". When I received the car back again though I noticed my keyring now had two petrol filler keys rather than one. They'd changed the filler cap for a vented one but forgot to tell me. The plastic part on the inside of the cap was black on the original but the cap now fitted is blue inside. Maybe the colour denotes vented or not. Anyway, emptying a tank from full on a hot day caused no hiss when I went to fill up again. Hope this helps, /Phil. Link to comment Share on other sites More sharing options...
ashaughnessy Posted July 18, 2002 Share Posted July 18, 2002 My current other car (Nissan) does this and I've had a Peugot that did this. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now