Hi Everyone; I had a squealing noise on my 56. I purchased a used one from an individual on the list. I cleaned it flushed it out and painted it and put it on my car. It still makes a squealing noise, maybe worse than my original. I used regular power steering fluid. I may have got another unit that squeals. I did turn the steering back and forth to work the air out. Has anyone ever rebuilt one of these units or is it better to send it away to be rebuilt? I do not know what else to do. Anthony