gp97

Long-term low level noise in power steering pump. Have replaced entire system (rack, hoses, pump, etc.) but noise is stiil there. Had several pump replacements by different mechanics. First two failed within two weeks. Third lasted about a year (that one also involved replacing some leaky hose), until the very cold spell in New England this winter. Found an excellent, meticulous, experienced mechanic who I had replace the whole system but much to his and my frustration the low level noise is still there, though the steering works perfectly. Its a 1997 Geo Prizm (i.e. a Corolla in disguise) which has been in the family since it was new and has been lovingly and conscientiously cared for since the beginning. I really like the car and expect to get many more enjoyable years out of it. Would really like to find out whether the power steering noise is just a chronic problem with this year or whether something can be done to fix it--anyone have experience with this?