Well I decided to suction out the power steering fluid inside reservoir to see what color it is....I would say brownish..

I used GM PS fluid to refill the reservoir. I think I will have to do this again in a few weeks. The new PS pump does whine slightly where as the old pump was dead quiet. Mechanic stated those Delco pumps require a 500km break in period and it should quieten down a bit...huh?

After the break in period, I will keep on top of suctioning out the reservoir.
Otherwise it may require a good PS steering Flush soon, If it does not clear up.

Update: on new Delco Power Steering Pump after 300 miles.
Every weekend I have suctioned out the reservoir now 3 times using 1quart of GM PS fluid, and finally it has quietened down to a level that sounds and acts like a normal pump.
It was on the last suctioning where the fluid became much clearer, and I once again added 4 oz LubeGard PS fluid + GM fluid as mixture again, and then it seems to have freed up with less whine. I guess there is break in period on new rebuilt pumps.
If I ever do this again I will have the system flushed first before new pump install.
I am going to leave the fluid in there now for a few months to let it really break itself in and then redo the fluid in the reservoir again towards new year.

Glad the pump finally quieted down Art, one of these days I'd like to flush mine out, there are a lot of other things I need to get done first, I did suction out a lot of the old fluid and replace it a while back though.

William Thanks. I think the PS fluid on our GM vehicles should get changed out about every year if driven lots or every two if less than 20 k per year if reg PS fluid is used in system.
I know that many manufacturers now have switched to synthetic ATF+4 in Chrysler & other pumps, that ATF should last longer.
I suppose the other neglected fluid is brake fluid, deserves a refresh mention too.
Yesterday I had the Buick out for a 150 mile cruise and noticed that after doing some slow figure eights, full locked each direction, that there probably was some remaining air in the system. It sure is smooth today now even when cold at first start.
Next is a 4 wheel alignment again after 16 months, to make it all good again.