Ford Repair: power steering pump, power steering pump, milky brown

Question
1992 explorer just purchased from private owner. pump whines after fluid warms up(driving 15 minutes). fluid level is full. color of fluid is milky brown. pressure hose looks new. Air in system? Bad pump?

Answer
The fluid may be worn-out, contaminated, or the wrong type.  If the pump was bad, it would whine all of the time.  If air was in the system, the fluid would be full of little bubbles and assist would be low.  If the system has no leaks and is full, any air would work out as the vehicle is driven.  The fluid should be red or pink, some new fluids are purple.  I would find a shop that has a special Power Steering Flush machine and have the system flushed.  The new fluid will probably have conditioners added to extend the life and quiet the system.

I hope this helps,
Dave