Mechanics

FUEL LEAK

1996 Holden Commodore • 6 cylinder Automatic • 236,000 miles

I have a 1996 holden s/wagon that has a fuel leak, sometimes. The hoses are new and the fuel tank has been checked for sweat leaks. The mechanic thinks it is in my head! I hadn't smelt it for a while but after a trip to melbourne two days ago after driving to the shops, got out of the car and smelt petrol. Looked under car and small drips were coming out from the hose and a cm wet spot above. The next day dropped the little one off at day care, the same thing happened. After dropping her off, looked under, it had stopped. Drove around the corner to work, two minutes away and nothing. Any ideas, is it pressure from somewhere?
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Gypsie
November 27, 2010.




Fuel leaks are easy to detect due to the smell and stains it causes but not too easy to pinpoint due to the fact the fuel dries up very quickly and the stains can cover a large area as the fuel can seep along surfaces.

If it is dripping, it should be from a pressurrised source. You mentioned noticing it leakng from a hose, if there is any joint near the hose, it could be the fitting is not secure or the sealing is bad.

If it is from the fuel tank, it migh occur only when the fuel inside tank is more than a certain level and would stop leaking when the level drops.

A visual check is required and maybe you need to top up the fuel as well.

KHLow2008
Nov 27, 2010.
I did take note of the fuel level but so far inconsistent. At the moment it is 3/4 full but last time it was 1/4 full, when the leak occured. I will get the mechanic to check joint near hose but any other ideas would be useful.

Tiny
Gypsie
Nov 27, 2010.
Under such circumstances it is more likely to be a pressurised point leaking.

Some leaks would only leak at higher pressure and not when the pressure is slightly lowered so you might have to simulate a higher pressure to test. If it is from the fuel delivery line, manually bypassing the fuel pump to make it work without starting the engine would increase the pressure and easier to detect the leak. Clamping the return hose under above testing would be even better.
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KHLow2008
Nov 28, 2010.

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