I own an older model of this HF Air Compressor:

http://www.harborfreight.com/1-3-hp-...sor-97080.html

As far as I can tell, only the tank and frame are different, the gauge
set-up seems to be the same.

In any case, the hose leaks at the quick release coupler on the tank
if any "tension" is put on the hose. As soon as the hose gets just a
few degrees from straight out, the fitting leaks. As far as I can tell
it's the quick release coupler, not the hose that's the issue.

Is something that can be cleaned/adjusted or should I just replace the
fitting?

Thanks!