Good Evening & HELP!, I'm new here....could any one help with my good Samaritan effort that back fired?
6+ months back I made the mistake of topping my wife's car off with traditional mineral based power steering fluid (25% down).
Within a couple months a whining noise started on when turning the wheel on slow and hard lock to lock turns.
The fluid was murky (dark black/brown)and a little foamy. I ran the car this way for the last month+ (smart eh?)with no reduced capacity of the power steering and no additional resistance or effort to turn the wheel...

In an attempt to flush out my Power steering I did the following...
1) pulled the reservoir emptied it and reattached it and the supply hose. 2)I pulled & extended return line into a bucket with a clear line. 3)I started the car and filled the reservoir (with Synthetic Pentosin CHF11S) and started the car and continued to fill till the return showed line was all the new fluid 5)I buttoned it back up and started the car and monitored the reservoir level.

I started the car ran it for about 3 minutes and all appeared to be golden no noise the power steering worked fine!
My wife barley went block ( a country 1/4 mile)and the power steering stopped working!
I then ran the car several miles muscling the wheel and still no power steering.

Observations:
No noises that I can hear from pump(with the car running), no leaking (except slightly around the cap), I see the return line inside the reservoir pouring fluid back into the reservoir, Very, very slightly foaming in the fluid.
has anyone had a similar experience? Is it the rack or Pump and how can I tell? Maybe it's air?
Thank You In advance For your help!
Sincerely,
Desperate Dave

 

Im thinking air lock?, I always do mine with the car OFF. Same as you did it except, raise front wheels and have a helper turn wheel lock to lock. The same flush is done and no chance of stressing pump or rack. There is probably a procedure for burping it. Someone will chime in...