High power steering leak at the pump connection

it may be a problem where the connection is on the pump. if you can take the line off and check inside pump for nicks or depressions where seal is supposed to go. also, check for old seal still in pump.

I replaced the hose with a new one , but after awhile it started leaking from the same place which is from the back of the nut of the hose, not though the threads and started leaking after few days of been installed.
The hose has a Teflon washer seal and what I heard is that the nut has an o-ring inside the nut which if it goes bad it will leak from back of the nut and is not serviceable. When I pull out the old hose I checked for old pics of seal which did not have any, it all came out with the hose. I will pull the hose off as soon as it stops raining here California. Thanks.

ok I hav emisunderstood the question I thought it was the hose. some of those nuts on back of pump have an oring others don't. If yours doesn't you'll know as soon as you pull it off, put some white Teflon sealer, not tape on threads and tighten it up that should take care of it.