I have a 2003 Acura MDX with 120,000 miles on it. I live on a mountain road that goes from 5,200 feet to 7,400 feet in 7 miles. When I head up the mountain and go around switchbacks, at the higher altitudes the power steering goes out when it’s very hot outside and I usually have the air conditioner on. I’ve had the power steering and sensors replaced twice and it hasn’t helped.
You don’t mention replacing the serpentine belt and/or tensioner. If the belt has been replaced recently, have the mechanic check that the tensioner indicator is within the specified range. I am thinking the tensioner may be reaching the end of its travel allowing the belt to slip.
Also, does the ‘bat’ light come ‘on’ when you lose power steering?
Hope to help.
+1 to Researcher’s question. Between the alternator, the AC compressor and the power steering pump, there’s a lot of load on the serpentine belt. If the belt doesn’t have sufficient tension, the belt may slid on one of the pulleys. Which one will depend on device load and total belt wrap (friction).
What power steering component and what sensors have you had changed? Were they changed to try to fix the stated problem? In future, feel free to post here before changing parts. We might be able to save you lots of money.