so im running a late model gm serpentine power steering pump in my project. from about a 93 blazer if I remember right.
anyway, its now whining any time the engine is running. no change with steering operation. it did not do this a year ago when I tore the thing down for paint and body.
any ideas why it started? I cant think of any changes other than fresh fluid.
also, short of pump replacement, anything I can do to quiet it down? id really hat to change the pump before I get the thing shaken down. im thinking some of this lucas power steering in a can should do the trick for a while at least. long enough to get a couple hundred miles on it and everything checked out.
so, feedback/suggestions?
PS pump whine usually comes from low fluid supply or the pump itself is worn out.
A good friend of mine swears by a method he's been using for years. He suctions out the fluid from the reservoir, then fills it with Seafoam Trans Tune. Run it and turn the wheel from lock to lock several times until it quiets down. Shut the car off, suction out the reservoir and refill with fresh power steering fluid.
I though he was full of E36 M3 until I watched him do it to two separate cars. One of which was another friend of mine and it's been over a year and the pump is still quiet.
Wonder if that would work on a whining auto trans pump, hah. I was hoping mine was the PS, but pulled the belt and the noise didn't go away. 
In reply to Dusterbd13:
Lucas Oil offers a power steering fluid conditioner that has been known to quiet some pumps, one of those things that is cheap to try.
Nah, Just put some gear oil in it.
Oh wait ! Is ATF/PS fluid considered gear oil or hydraulic fluid. Hmm, now there is another idea.
I thought my wife's power steering pump was making noise, so I replaced it. Noise was still there, but I couldn't find it. Sort of but not really a bearing noise. Told her to drive it till something detonated, but only the 10 miles to work and back; no field trips. That Friday, I get a call from her. She went the opposite direction from home to a mall, and the AC clutch fan self destructed and took out the belt. No easy parking lot fix. It was 2:00. A major snow storm was just starting. I was working. My trailer was at a friends house an hour away with a non op car on it. 6 hours later and 5 inches of snow on the ground, I finally got the car home. Fixed the AC clutch the next day laying in a foot of snow in single digit temperatures. Yea I was pissed. Coldest day of the year, and I'm working on the air conditioning.
Lucas power steering stop leak is one of the few products worth buying from them, will often quiet down a loud pump. I'm pretty sure the Lucas "transmission fix" is the same stuff in a bigger bottle. It's more or less really thick ATF loaded with seal conditioners.
