Ok. Now I'm about to go crazy.
Tested with the old self piercing valve, and it took 4 min and 50 sec to fill the huge 5 gallon bucket from the small coper line on the back of the fridge.
Drilled the hole to 1/4", and then did the test. 2min and 50 sec! No joke, it was double the speed.
Put it all back together, and it still drips, same thing as before. I don't get it. The water pressure coming out of the tube was super hard, night and day, but it still drips.
Here is the new drill valve in place.
Wasn't sure how much I was supposed to thread the valve into the first bracket that the rubber piece sits behind. I twisted it in maybe 3 turns, and the shaft barely sticks into the copper pipe. It doesn't leak. Wasn't sure if I needed to thread it all the way into that bracket, see pic. Again, nothing leaks on the valve.
Not sure what to do now. I just can't figure it out. What are the chances of the brand new water fill valve being bad. I tried the old one, and the new one, same drips at the dispenser.