Leaky outpost (pin lock kegs)

I recently acquired some used pin locks kegs. I've replaced all the orings and the poppet valves. When the beer coupler (plastic) is attached on either of the two outposts I get a very tiny leak, it is almost too small to see but it is definitely there as beer accumulates on the bottom of my kegerator. Can anyone think of a good reason this could be happening? Anyone experience something similar?

All I use is pinlocks so I will try and help. With the keg pressurized spray everything with soapy water and look for bubbles. Areas that are creating bubbles are the leaks.

Some possible leak sites:
The o-rings could be the wrong size and too thin I buy mine at HD and they dont leak(sizes are in my Sig).

Your coupler and or the hose barb could also be leaking. If you have taken them apart recently may be you reassembled them wrong or forgot to tighten or reinstall the gasket. They could also be dirty and need to be cleaned.

If you have an additional liquid coupler put that on and see if it still leaks.

Thank you very much. I've tried two size of o rings , maybe neither of which are the #10s, I'll have to swing by lowe's or HD tonight and see what happens.

If the kegs don't leak when the QD isn't connected can I rule out incorrect sized poppet valve?