How can you detect a petrol leak? Help please...

[Rob KE25]

Hi.

I've had my tank tested at the radiator shop, checked all the lines, and tightened the fittings.

Still there is a petrol smell if I leave the car to stand for a day in the shed. It could be the filler cap not sealing properly, but the smell is quite strong in the car if it is left to stand, and particularly in the boot.

I've run the car in the shed, checked for leaks too.

It seems to get a stronger smell the longer the car is standing still in the shed.

I heard of a fluid you can put in petrol, and with a strong fluro light you are supposed to be able to see the gas coming out of the apparent leak spot. But apparently this is for bigger systems than cars.

Any help or ideas would be appreciated.

Thanks, Rob.

[ian]

hi rob
check to see if the vent line has not got a split in it ,
or it may have been dislodged

[oldcorollas]

it only take a tiny amount of petrol to make a strong smell, so you me be chasing somehting very small..

there are also powders and things like this, used to detect leaks.. chuck on and see where the colour changes... may not be cheap tho? look to aero stuff perhaps?
http://www.eldoradochem.com/pb/LD-4-PB.pdf

[Blair]

I had this same issue once with my old ae82 twincam.
After a loooong time trying to find out what was the cause, I noticed a small pool of petrol sitting on my intake runners, turned out that my injector seal rubbers were hard and cracked causing it to leak.

[pandaah]

a good way to check if youve got leaking fuel, is to get a compressed air gun, and shoot it in your tank and pout a rag around the filler neck, hopefully it should pressurise the tank enuf to make a few drops come out of where its leaking for you.....

works a hundred times better on diesel cars as obviously they dont have an in tank pump but you could always give it a shot to see if its one of your tank vent lines?

[parrot]

I had a tiny split in an AE86 tank that would stink the car out, even though it is under the car. Went over it with a fine tooth comb without luck. Eventually I put a couple of litres of fuel in, covered the inlet and swished it all around. After doing this, I could see a small area of wetness around the split that would rapidly evaporate away and dry. Circled it with a marker pen and did a temporary repair with that tank putty stuff till I located a replacement.

[andrew_mx83]

cigarette lighter.




disclaimer: not really

[Blair]

That was my first thought lol

[Casey-G]

Is it a fuel cell or a standard tank?


Also, if you use the wrong type of braided lines (if you have any) you will get the smell. you need teflon lined lines if im not mistaken.


my 2c

[Invid]

Just ordered some PTFE (teflon) hose from this place. Cost $25 p/m. Cheapest I could find, and happy to do small orders.

http://www.radcoflex.com/products_flex_ptfe.html

Or for finding the leak

Reveal™ Leak
Part no. A-680Plus
http://www.uvp.com/reveal.html

They have stockists in Vic (supposedly)

[Rob KE25]

It's a standard tank, with rubber automotive fuel lines. Ordinary stuff including custom surge tank for carbie to EFI conversion.
A few pics...

[Rob KE25]

Thanks for the feedback. I'll try the suggestions. Didn't really consider that the petrol smell could actually come from under the bonnet. Seems strongest in the boot though, by a fair bit. The Reveal Leak product available through Scientifix pty ltd Victoria, Clayton. 1800 007 900.

They are getting back to me with a price. Need an ultraviolet light though too.......

Any other suggestions, keep them coming!

[SilverRA23]

Its pretty common for a car with a surge tank in the boot to stink of petrol even when there is no leaks.. That is why its becoming more common to move them under the car. (and to get rid of the noise factor)

[oldcorollas]

ahh, all those connections in the boot.. if each one or even just a couple have a tiny tiny leak, it all adds up.
can't move the system under the boot?
do you still have the fuel tank vent system hooked up? if not, it could pressurise with heat and help force a little bit of fuel out somewhere (on the low pressure side, so you wouldn't see it normally)

[YLD-16L]

The smell will be permeating through those rubber lines.