Welcome back:
If you are replacing the o-ring and the threads are going on smoothly (not cross threading), the actual rack may have damage at the connections. I hate to say this, but disconnect it where it leaks. Take a flashlight and a mirror and inspect where the pipe goes on to the rack. Remember, a re-manufactured component was in another vehicle. This may be why it was replaced and the re-manufacturer could have missed something.
If you find no burrs or damage, try it one more time using new o-rings and make sure to lubricate everything with power steering fluid so the o-ring doesn't drag when tightening or catch and get nicked when installing it.
Let me know what you find.
Joe
Thursday, April 25th, 2019 AT 2:12 PM