2004 Gt Power Steering Does Not Work (occasionally). Help?

[CWSpartan]

Hi guys I just picked up a 2004 mustang gt 5 speed last week. I've noticed that sometimes the power steering just does not work. For example, I was backing out of a tight space in a parking garage last night and it was just extremely difficult to move the wheel. But when I started it up this morning, it worked perfectly fine- I could move the wheel with the car standing still with minimal effort. The fluid is at the right level and it's not discolored at all. The pump does not make any strange noises. Also I know that the power steering and brakes are linked in these cars, but this has had no effect on my brakes. Any idea what might be wrong?

 

[wmburns]

Just wondering. Have you checked the lower ball joints?

How many miles? How does the car drive otherwise? How low/high is the idle? Does this car have under drive pulleys?

 

[CWSpartan]

I had it inspected before I bought it and there were no balljoint issues however the left front inner tie rod has about an eighth an inch of play in it. The car only has 56k miles and it drives perfectly other than this. Steering functions perfectly at speed. This only occurs when I'm turning at very low speed and it doesn't even happen every time I drive. It idles right around 700 rpm, and as far as I know it is not equipped with under drive pulleys.

Just wondering. Have you checked the lower ball joints?

How many miles? How does the car drive otherwise? How low/high is the idle? Does this car have under drive pulleys?