Outside Woodford hydrant that's about 30 years old. Over the years the pressure has been deteriorating to the point I knew I had to do something. Checked YT vids and dreaded digging it up or dissembling the head. I noticed the faucet opening was restricted so I proceeded to use all kinds of tools; hammer and chisel, screwdriver, coat hanger, file, PB Blaster, etc. etc. to try and expand the opening. Low and behold after about a week it cleared and pressure was restored, lots of mineral deposits came out over that week. Point of the story is never give up, keep hitting that brick wall and eventually something will happen, lol.