Hi guys

I have a 1994 180x that has started leaking from the fuel sender area of the tank.

I am a relatively capable DIY mechanic and have tried the following:
- new sender O'ring
- cleaned up all surfaces
- changed/checked rubber pipes
- new set of m5x0.7mm bolts and cleaned up the female threads

None of this helped.

I then realised that I had left the breather hose blocked by accident, from an earlier tank re-furb. Unblocked this and leak turned into a weep. Improvement, but car still not roadworthy.

I'm stuck now.

Strange thing is, rather than leaking from inside of the O'ring out, it actually if you look closely enough, appears to be weeping from between a metal joint. So if you imagine the inner metal gold-coloured ring that contains the m5 bolt holes, the joint between the outer edge of that ring and where there main casing of the tank starts - it looks likes it's leaking from that metal on metal joint. Has anyone come across this scenario before please? Is it possible for this to even happen?

Thanks

Jon