Fuel leaks/smell

Straight to the point, how does one eliminate fuel leaks from the many joints in the mk2 fuel system?

I have a standard 3.8, twin su, fuel system. I regularly tighten the many joints - fuel filter, float chamber etc. even going to the extent of purchasing a spanner and grinding it down so it easily fits on the rear float chamber fuel feed. I have replaced all the fibre washers and the aluminium washers. But still there is a slight leak/petrol smell after a few weeks.

Any tips would be great.



I replaced all the old junk clear tubing and the regular fuel lines with fuel injection hose, Then where possible replace all banjos fitting with the later nipple fittings on series 3 etype.
The leaks will go away…cranking down will only make things worse…Find washers from burlen they are lots better.

Most of the washers are from Burlen, from their SU refurb kit.
The nipple fittings sound worth investigating.


I loosen the fuel to the carbs and reset the banjo bolt completelty on both carbs at one time, this way its adjusted together, not each carb alone.

Generally the main sources are a rusted through fuel tank, failing flexible hose or failing float valve needle jets – that said even when in good order after a hot run there can still be a little overflow from the float bowls – all liquids expand when hot, hence the overflow pipes.

Replace flexible fuel hose with ethanol proof hose (8mm internal diameter) – we had one become ‘sponge’ then split – thankfully caught before the fire that has ruined many other classics (and also some modern cars). Thus tank to pump, pump to hard line, hard line to flexible – 2 metres/yards should do you.

Unless already fitted, replace carb float needles / carb floats with ethanol proof variety; Refer Burlen / SU Carbs.

Do also fit an inline cheap as you like fuel filter between tank and pump – change when you change the oil. The c**p that the half a quid / half a buck filter catches is astonishing – change at oil change.

I have replaced all the fibre and aluminium washers again on the cars and they are leak free for now. I wonder how long they will remain that way.
I didn’t tighten them up much as I didn’t want to over tighten them and I was happy to let them leak a little and tighten until they stopped. They are supprisingly lose (not tight), if that makes sense.