IMHO, it sounds compromised.  Seeing as you have the engine apart, I would try replace it at this stage.  It would be a mission if it breaks off during assembly, as that would mean stripping again, and you would still have to remove the broken stud.

Well, I'm not going to argue because I don't know.  My motor bike takes almost 4Lt and this volume seems rather low for a thumping twin diesel.  Maybe it is a misprint in your manual.  You'll have to wait until the experts reply

Ahh, you're back. Good to hear all is well and it was just life that has kept you away.  Have you been harvesting olives again?  Looking forward to your write ups

I have noticed that VP has not been on the forum for some time now.  I sincerely hope that he is just on holiday and not having health issues again.  Maybe Bob has some news?

Good on you for a speedy response.  The learned members will soon comment.  In the meantime, try get a few pics of the serial plate as this will help determine model and year

I suggest you post some pictures of the setup.  I'm assuming the serial plate mentioned is on the pump, and not the engine that drives it.  Is there an engine too?  There were thousands of Lister based pumps and generators in SA in the old days, at police stations, forestry stations, government buildings and of course, farms

That looks stunning VP.  You deserve to show it off.  Well worth all the effort and expense.

Looking great Bob.  I wish I had your skills