Parking brake release cable
 

I thought that I would pass this on.

My parking brake release cable broke on my 2003 Sierra today. I pulled on it to release the parking brake and the steel cable snapped. After looking on the internet, I found a replacement at O-Reilly's. My local store did not have one but they ordered one from another store and had it delivered to their store in about 3 hours. It comes as an assembly (the cable, the handle, etc). The installation was simple. It was $36.99, not cheep but not outrageous.

The part number is Dorman 924-305. I hope this helps someone.