Power steering woes

Hi, has anyone out there had to replace the high pressure power steering hose on their Maxima in the past. I have a 2000 Maxima GLE and last week replaced the high pressure power steering hose because it was leaking. I took it to my mechanic who I trust and has a solid reputation. Apparently this part is a proprietary part only from Nissan and that was at $480, he sent it to a local hose shop and had it rebuilt for $150. I no longer have a the leak, but a low or slow speeds I get a loud noise like brakes grinding when I turn the wheel. My mechanic has checked and re-checked everything and still cannot determine what is causing the noise, any ideas. I would certainly appreciate any feedback on this one. An update to this problem, yesterday morning I had to go out briefly, it was cool and damp at that time and much to my surprise the car was as quiet as it was before the repair job. However; 2 hours later when I went out and the temperature had risen the noise and vibration returned. I will be going back to my mechanic with this little bit of information tomorrow after our long weekend.

After steering oil had been spread on the road, pump bearings did miss the lube... Theyre possibly now somewhat damaged, causing this noise as they become under more stress when wheels are turned. I guess only pump/bearing swap will stop the noise. No more harm done if u just keep drivin ... u may pinpoint the source by listenin in: long screwdriver on the pump, ear on handle (or just buy a 5$ mech stethoscope)