Hi thank you for your question. My name is ***** ***** I am a fully qualified technician with over 30 years experience and hopefully I can help you.
As you have checked the power steering fluid that can be discounted as the problem, this means the most likely cause of the problem to be the power steering pump itself which is not producing sufficient pressure. There is another possibility that the belt driving the pump is not gripping sufficiently, this would normally give off a squeal when trying to turn but not always.
The last component in the steering is the steering rack but when a rack fails it normally leaks and very rarely makes the steering tight.
Finally the steering may not be tight due to lack of power steering but due to either the steering u/j on the shaft becoming tight, this will give a notchy feel, or the swivels on the front suspension but again this is very rare.
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