Pontiac Repair: Power Steering Trouble, power steering trouble, power steering fluid

Question
I have a 2004 Pontiac Grand Prix with just over 100,000 miles on it. I’m having trouble with what I think is a power steering issue. The other day I was backing out of a parking spot and when I was turning my wheel back to the left to straighten the car out I heard a pop sound like as if someone’s joint cracked. After that I wasn't able to make my left hand turn around the corner. I took a look at the car, nothing is leaking, the power steering fluid is full (but it's a light brown color), and I have not heard the noise again. I’m able to drive the car but now it is a real effort to make left hand turns at low speeds. I can turn right just fine at any speed and can make easy left hand turns at speeds greater than 20 mph. Could this be a power steering pump issue? And if so, can pumps be fixed without replacing them and is it hurting the pump more to drive the car as is? Thank you for your help!

Answer
the issue is the steering gear, the lower pinion bearing sounds like it seized and broke that was the noise you heard, to correct it you will need to replace the gear.  The longer you wait the more metal debris will float in the system, possibley damagin the power steering pump