Bosch EPVE leaking from outlet port

[magictorch]

I thought I had cured this leak but it has come back to haunt me.

I have a leak from my bottom right outlet port on my Bosch EPVE pump 0 460 494 427 601 - 2. I have replaced the copper washer and swapped over the outlet port to another one as a process of elimination. I have tightened it right up with a ring spanner to the point I don't want to shear the alloy.

I had the pump overhauled at the beginning of the year and the garage has replace the torx head bolts holding the cast block onto the alloy body with an allen key bolt. Would it be possible for fuel to creep up this (if the rotary head seal was not ok) and pop out to make it look as though the outlet port is leaking?????

How tight should the outlet port be? Like I said I am cautious about over tightening and stripping the alloy thread.

Cheers
Jamie