F2 style oil cooler fitting leak?

I’ve made up stubby oil cooler hose connector stubs for my F2 sump. The stubs are short sections of the original steel lines with a flare fitting silver sided on to connect to the flex hoses I’ve had made up. The sump end of these stubs is where I’m having trouble with a bad leak on the pressure feed line. Fitted o ring under the two bolt flange, and silicone as well.
As soon as I start the bike it blows oil from between this bolt on flange and sump.
My next experiment is putting 2 o ring and silicone on the joint, and giving the silicone 24 hrs to cure, in the hope that this will get more of a seal.
Has anyone else had trouble with these fittings, and if so, what have you done to fix.

Greg,there should be no pressure on the feed line to the cooler,there is an open port to the sump on the return side so only flow will be present unless there is some blockage somewhere

Thanks Bif, will check for blockage first, then once certain it’s free flowing delve deeper into the mystery. As the F2 uses the double pump there must be at the very least low pressure produced, given the F2 stock cooler sits up near the steering head?
Strangely, from stock, my 85F model had the dual pump already, and the sump with cast, but unfinished oilways for the cooler lines. I assume the cooler side of the pump must have just run away doing nothing…have you seen this before?

Hi speedy, I’ve had a few ff engines in pieces and they have had the single oil pump and unfinished sump,
The oil cooler pipes on my f2f used to leak accasionaly, the issue I had was poor quality O rings, these are what I use now with no issue,

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Hi Pete,
thanks for the tip, had tried a couple of different brands I had. In the end I succeeded with two O rings on the pressure side, with a thin smear of blue silicone. Now no leaks, have had the motor starting and running cleanly with no leaks- progress! Now to reassemble front end, and do all the tidy up little jobs before rolling it of the bench.
I`ll order some good quality o rings in the size that you recommend, cheers Greg