My 2001 suburban parking brake stopped working at 40,000 mi. I had the brakes done at 70,000 and mentioned it to the service tech (not a dealership) got the car back with new brakes but parking brake still didn't work. have 108,000 miles now and just took the car to a reputable brake guy. As a side note I just mentioned that I would like the park brake checked because it hadn't worked since 40,000 mi. He immediately knew what I was talking about. He said he had seen vehicles with only 10,000 mi on them with a non functioning brake. He said that there is an expandable ring that is held together with a spring, when you set the brake the cable expands this ring putting pressure on the drum that the rotor is attached to. when you release the brake the spring is supposed to pull that ring back together - releasing the pressure on the drum. However, that spring is known to fail (very often) and the ring doesn't pull back together. So when you drive the ring wears against the drum and ultimately wears out and is unable to hold the vehicle when the brake pedal is pushed down. I checked on recalls and found out that this item has not been recalled - why, I don't know - because according to the brake guy over 80% of all 2001 suburbans that have this type of parking brake are broken when they come into the shop. He did say that most customers don't even know that the brake doesn't function. I guess they figure that if the pedal goes down, it must be working. I'm going to have him fix it when he does the brakes but unless the part has been upgraded, it will probably fail - soon!!!