Oil filter sealing ring

[Last]

I just changed the oil and filter on my V40. I installed a new sealing ring over the treads and screwed the filter in, just tightening it by hand.
I started the engine and it was leaking, so I had to tighten it with a wrench, which stopped the leak, but then the O ring slipped down over the threads and now the filter is on the chassis, metal to metal, without the ring. There is now a very slight leak. If I unscrew the filter will it completely drain all the oil, or just what is in the filter. I use Mobile 1, so unless I can help it, I do not want to lose all the new oil.
Thanks

[JDS60R]

Less than a quart will come out. The inlet for the filter is above the oil pan resivour.

get a new o ring and put it in the correct groove. A little oil on the o rings helps it slip in nicely. I like to push the oil filter up a little and then screw the base up by hand ( as far as I can before needing toque wrench to apply 25Nm. Your filter will be stuck up in the engine so it should be easy to fix. Have a drain pan ready and a buch of paper towels.