fuel leak when full

[markey b]

random one, i've got a fuel leak when the tank is brimmed, tried to find it the other night, when the tank was literally full to the top, and when i jacked up the rear it pissed out from the front above the fuel pump and filter

from what i gather, the usual suspect, the yellow bung is on the side, but mine seems to leak from the front or top.. do the sender unit seals usually go, or is there pipes above the tank that could have perished?

can anyone suggest anything without me having to drop the whole tank, i dont use the car much so its still got half a tank left and will prob not be empty for another month lol

[Rusty]

Mines does this aswell, i've had the tank off and still can't find where the leak is coming from!

[Big Steve - Raider]

I bet it will be the rubber seal under the fuel lever sender unit

[IANMM]

there you go...

https://www.rtoc.org/boards/showthread.php?t=4766

[5teve L]

Erm, a bit obvious, but don't brim it in future ??

[Sparkie]

the first national day i went to at Croft, i suffered this problem. i brimmed the car in tamworth, and noticed it pi$$ing out from under the car. - pulled off the black bung that hides the fuel sender, and it was leaking badly.... so i just drove full wack down the motorway. - by the time i got to Scotch Corner, the headgasket had blown and my valve stem seals had melted - but thats another story...

it could also be the breather hose has popped off the front upper part of the tank?

[James5]

Erm, a bit obvious, but don't brim it in future ??

That's exactly what I do as I have no idea where mine is leaking from and it is defo not the sender unit somewhere over the passenger side of the car but only when full and the tanks was new about 3 years ago

[J$£5GTT]

if it can be fixed with tank on then great,but if it were me an it was hard to
suss it,then get stuck in an take tank off,repair any holes/cracks??
an replace the fuel pipes.


but check the sender unit/gasket first.

[markey b]

Erm, a bit obvious, but don't brim it in future ??

try to avoid it, but dont like running it low on fuel, noticed it the night before FCS when i brimmed it. the fuel sender was wet, and the inside of the car stank of fuel, once it dropped down to just abouve 3/4 it was ok, hope its the sender seal, i'll order one up from ren

[Tillax]

I've had two separate leaks from my fuel tank, the first leak was small and came from the bung, I can't recall if that was driver or passenger side but it was a constant leak which didn't seem to matter how full the tank was. I then replaced the fuel tank with a new tank which was installed by Renault themselves who apparently had no clue whatsoever what they were doing and I ended up with a fuel leak which was much worse, only this time it only occured when the tank was full and would make the whole car stink. When I looked under the rear seats at the sender unit there was a small pool of fuel and neither the tank nor the sender unit looked aligned correctly. I took it back to them a couple of times to fix it but eventually gave up and took it to Mark Fish who aligned it all up correctly and checked the seal was in place. Job done.

By the sound of things the seal is prone to leakage if the tank and sender unit are not alligned properly and aligning it properly is a bit tricky.

[markey b]

seal and ring is only £11+vat from renault, got it on order, just hope it works!

[Ashy]

make sure the seal is fitted correctly, it has a notch out which lines up with the tank and sender, if its not aligned it means the seal doesnt sit correctly and thus leaks!!

Also check the breathers as suggested, sometimes the one on the top pops off and leaks!

[Kris M]

it could also be the breather hose has popped off the front upper part of the tank?


As sparkie said...make sure it hasnt popped off the sender unit as this will cause fuel to overflow down the front od the tank when brim full

[markey b]

are popped off breather 'fixable' with the tank on, and the biggest ask of 2009 from me...

does anyone have a pic of a tank, so i can see where they all are without having to drop mine

[Kempy]

There is a pretty good drawing of it in the haynes manual mate.