The power steering may leak fluid at the pump, hose, or steering gear. This can be caused by one or more hoses not being clamped tightly enough. The repair involves adding new clamps and seals to the power steering hoses at the pump and steering gear.Google+
Car Problem Reports
Lincoln MKZ Power Steering Fluid Leak From Pump, Hose, or Steering Gear
Lincoln MKZ Problem
Average Mileage: 33,200 mi (6,000 mi - 60,000 mi)
Visitor, 2011 Lincoln MKZ, 33,600 mi
Ford edge same as MKZ, noticed fluid is dark and level is halfway between low mark and bottom of reservoir, so is significantly low. More importantly, I purchased the car as CPO 4 months ago and level was ok.
Visitor, 2007 Lincoln MKZ, 60,000 mi
noise when steering
Visitor, 2010 Lincoln MKZ, 6,000 mi
Makes humming noise when the steering is turned, even very slightly, particularly in the morning and when the weather is cold. I was told that power steering hose and perhaps pump would need to be replaced.