I just had a new radiator fitted to my 110 yesterday (moral of THAT story - do not believe the story that synthetic rope doesn't spring back and I have a hole through my radiator from a winch hook to prove that it does!!!) and I took the opportunity to fit some metal bungs into the top of the rad and the thermostat housing, they have been sitting on top of my fridge for a few months "pending" and it seemed a good time to put them in since the coolant was out anyway.
First impression is that as they both leak (pink stuff on the rad and the thermostat housing) the immediate benefit of replacing the old plastic ones seems a bit vague! They don't leak a lot (a pink stain and a few drips on the thermostat housing) but any coolant leak is too much for my liking.
What do the genuine old style radiators use under the brass bungs - do they have a copper washer, fibre washer, or just metal to metal? These are as tight as I dare.
I am a bit wary of fitting a copper washer between two bits of aluminium and then sitting them in a hot wet liquid - might cause electrolytic corrosion or would the antifreeze mix stop that? - anyway I don't think the old LR brass bungs have a washer under them but I don't have an old rad to check that - can anybody confirm please? A fibre washer might be the other possibility - if I can find one the right size, which is not guaranteed around these parts... in fact it is more likely that I won't find any!
Otherwise I will have to go back to the old plastic ones to be safe.
Ta