TD5 fuel tank still leaking! Do I need a new tank?

My fuel tank has been leaking from the top around the pump seal so I thought it must be the seal. Changed that and fired it up just now and its leaking again...really its just a very small weep, but as soon as I wipe it dry with a rag diesel seeps along the surface. This happens when the car is turned off and the pump is off. The tank is currently half full so I really don't have an idea why this is happening.

I definitely put the seal in the correct way and the fuel lines are definitely not leaking.

Perhaps I haven't tightened the black ring enough? I think there is a problem with the white ring which the seal sits on, but I haven't found a replacement one anywhere.

Image attached. Seepage on the plastic tank on the bottom right.

Are you sure its not coming from one of the feed or return pipes or connections on top of the pump and trickling down onto the seal area.

It's definitely not coming from the pipes. Possibly the connections but I can't tell. If it's the connections will I need a new pump? Or can the o-rings be replaced in some way?

I think it may be residue from when I put it all back together. Since my first post I've taken it all apart once more, double checked that the seal is fitted correctly and retightened the ring. I will drive it about and see what happens over the space of a week

With luck it maybe just that (residue)

Is the car upside down? should not leak at top as only air there, if it leaks when you fill it right to the top then there is a problem with seal or maybe if driven around it can splash up but if the tank is taken down to 1/4 full and there is still diesel there I would think it is the connections, when I first got mine it leaked if it was filled right up, went back to dealers, they tried 3 times to fix it but with no luck it would work lose after about 6 weeks in the end I took it off and refitted it, I also cut a bit of polystyrene to fit between pump and pump cover in boot.so as the cover was tighted it also held pump down as what used to happen is if it was filled up the pump would float out if the retaining ring came lose, that was over 10 years ago and have had no more problems with it and have looked and ring still tight, I also found tank had to be low when refitting pump or the pump would float up and it would be hard to get all to line up and go in straight

I've also got a problem with my td5 fuel pump (defender) at the moment and I believe the 'o' seals come as part of the pump. Looking at it I'd say it could well be one of the pipes leaking, they do operate at a fair pressure on the td5.
Saying that, it might be worth replacing the fuel pump locking ring, is there a possibility it might be slightly distorted? It's not that expensive to replace.
At least you don't have to remove the fuel tank to get at the pump on the disco!

I think I may buy four hose clamps for each of the hoses just in case there is a leak between connector and hose. One looks a little loose. I have quite a lot of diesel in their at the moment so will use it up before taking it all apart again.

After some more investigating its seems it could well be the connectors. I have ordered some new aluminium ones along with a new pump, ring and hose clamps. If this won´t solve the problem I will be well and truly stumped. There seemed to be some diesel seeping when the car was stationary and the pump started doing its purge cycle - must be connector.

I have found the problem....there is a small hole in the pump where my finger is pointing to. I have spent ages fiddling with the seal, pump, connectors and hoses. It must have been damaged when the pump was fitted as its definitely not the original pump. Whilst filling the car diesel was squirting out the top and drenching the pump. I have ordered a new pump anyway and will fit it once it arrives as the fuel sender is now not working properly anyway.

Always nice to get feedback, glad you found the problem.