When is it necessary to change Power Steering Fluid when you are not experiencing any problems?
Compare the color of the old power steering fluid to the color of new power steering fluid. If the old fluid is dark or black in color it means it has become oxidized and requires changing. This is cheaper than replacing a power steering pump and/or a rack and pinion assembly because old fluid could no longer protect the seals.
Every 60,000 or 5 years…Or you can just wait until you hear the pump whining…