I had a leaky fitting to one of the oil coolers. I replaced it with a new one. £10 from Merlin motorsport. Its designed just as a push on fitting. I put a couple of jubilee clips on, its very secure and doesn't leak.
there is a thread about doing this.
https://www.merlinmotorsport.co.uk/p/90-degree-firtree-union-5-8bsp-hefp93-10
They do a different one which is less barbed for only £5
I then discovered the other end is leaking at the oil filter plate. Hmm should've just replace both hoses when it was all apart.
Anyway the crimp section was leaking and I heard you can get these re-crimped. Not possible on the car, I wondered how much force you would need to crimp it enough to stop the leak. Which is pretty small.
So Bodge of the week, I put a good quality jubilee clip around the crimp and tightened it as much as I could.
Its stopped leaking! for how long I don't know. if it last till the next oil change i'll change the hose or fitting then.