So I finally got around to doing my coolant flange. the part where the flange mates to the back of the engine had a small chunk taken out of the back and that was where it was leaking. I got everything back together and noticed that the O ring that goes to the other side probably got out of place because its leaking reallyy bad from that side. Are there any tips to keeping it in place when im tightening it? tomorrow when the sun comes back up ill be doing it all over again

 

You more than likely pinched it, use some O-ring assembly lube around the o-ring.