Here is a trap for first timers when it comes to Subarus and common faults relating to their steering systems.
Often a high pitch whining noise when turning the steering wheel is diagnosed as a faulty power steering pump and in many cases this would be accurate. The pumps are common for failure as they seem to be designed by the same chap that designed NASAs CHALLENGER.
The pumps fitted to almost all of Subarus range are common for letting go, spitting power steering oil throughout the engine bay and making a noise similar to a herd of small cats being drowned.
Replacing the pump often solves the problem but in many cases there is an additional fault that will mean the noise won’t go away or it returns a short time after replacing the pump.
This is how you fix and or avoid this if you are replacing the power steering pump.
Subarus are also known for giving a harsh shudder or “kick back” through the steering wheel when turning. This common fault is also caused by the following issue.
The rubber, low pressure, power steering hose linking the oil reservoir to the pump becomes hard and brittle. This allows air to enter the power steering system and gives the small infant whinging noise and or the harsh shudder through the steering. Replace this hose whenever you replace the pump and the world shall be as it once was (hose labeled in the image as a ‘suction line’).
If you are unsure if you have fixed this fault, run the vehicle for a while going to lock to lock, after a small period of time you should no longer have bubbles and foam in the reservoir. If you still have aerated oil, you have not solved the problem yet.