Fuel Tank Leak From The Top - Breather Or?

[hadders 0 1 Cars]

I’ve had the tank out whilst repairing the boot floor and it looked fine. I've never had any leaks before and after refitting, but its never been full. Today I filled it two thirds full and ran the engine up to temp, only to discover fuel pouring out from the tank. From the top by the looks. This is all whilst stationary. It eventually stopped once I’d switched off the engine.

 

Am I right in thinking this is likely to be a problem with the breather connection on the tank? If so is it possible to get to that via the inspection holes in the rear floor? I’ve checked these and the tank is dry around the fuel pipes and sender/pump. All pipes in the wheel arch are dry. I'm hoping I can drop the tank a little to gain access from above. Its got 40 litres in it now and I wont be able to handle that and I'd like to avoid siphoning it all back out again.

 

Anyone done this before or have any suggestions what else to look for?

 

Many thanks.

 

 

[Slo 283 1 Cars]

If it stops when you turn the engine off its more than likely a split rubber fuel pipe.

Edited March 16, 2014 by Slo

[hadders 0 1 Cars]

Agreed Slo, but it has been running without any leaks, with an almost empty tank, since I put it back in a few weeks ago, hence the confusion. I haven't disturbed anything recently, just filled the tank to two thirds.

[welshpug 1,666]

I don't think you will find much without lowering the tank unfortunately, with the rear of the car at a decent height and a good sized trolley jack supporting the tank you can drop the rear enough to have a peek over the top.

[hadders 0 1 Cars]

UPDATE: Taken the tank out today and the source of the leak was very obvious - a hole in the top where its in contact with the floor under the rear seats. The reason for it seems to be a drip of paint from when i treated the underside, so beware if you're rust proofing your car. I'm hoping the tank will respond well to some plastic welding tomorrow.