steering

I HAVE A 1990 Honda Accord ,problem started when my steering statded makeing a roaring sound steering got hard to steer, so i added power steering fliud , then it work but started again, i look under the hood and saw the fliud in the reservior over flowing .it got all over pulleys so i degrease them. ask the question to a radio program and the tech told me, as soon as i said fiuld was over flowing he said my rack and pinion was bad .so i had it replace. it work fine for awhile now power steering starting to make roaring sound again, shop told me rack needed to work rest of the air in the system out ,this would happenen in time .its been 4 weeks ,still makeing nosie. what do i do next? thx you very mush. p.s fiuld dos not over flow now.