Our 2012 Volt has an intermittent problem with a "thunk" noise which is apparently associated with releasing the handbrake upon startup. It started about 6 weeks ago and occurred once every 7-10 days. Today it occured twice. The second time my wife was backing out of a parking space at a crowded grocery store. The handbrake was released and she was applying the footbrake periodically. She heard the noise right after releasing the footbrake the third time (BTW, this is the first time its happened with the footbrake). These noises seem to be coming from the rear of the car. There doesn't seem to be any accompanying vibration. Has anyone else experienced this problem?

Mine has started thunking when I set the parking brake but not when I release it. I guess this'll give me something to have checked out when I take the Volt in for its recall (someday).

Mine has started thunking when I set the parking brake but not when I release it. I guess this'll give me something to have checked out when I take the Volt in for its recall (someday).

Mine does this too.

I experience the same... only when setting it. Seems to happen more frequently on colder days.

I get a thunk from time to time. It has never bothered me, and I just assumed that it was normal.

See this post from another owner that had a similar problem and got it fixed by his Volt dealer.

http://gm-volt.com/forum/showthread.php?6203-Observations-from-an-Early-Adopter&p=64910&highlight=Brake#post64910

See this post from another owner that had a similar problem and got it fixed by his Volt dealer.

http://gm-volt.com/forum/showthread.php?6203-Observations-from-an-Early-Adopter&p=64910&highlight=Brake#post64910
Good reference. I always use my park brake by habit without any problems. In addition to preventing the car from rolling away (if you forget to put it in park, but otherwise, there is only a small park pawl holding it, although all manufacturers have learned through recalls not to let their cars roll away), it also helps with the adjustment of the rear disk brakes, and makes it harder for a thief to break the shift linkage and push it away. I was once toad away in a different car in Chicago (Bears game day, a valid parking receipt on the dash, but a sign 50 feet away saying no parking on game day), and they actually used a slim jim to get into the car to release the park brake. With the low clearance and all and the electric park brake on, I shudder to think of them towing away a Volt.

We rarely use the parking brake, but when we do, it lets lose with a real loud, car-shaking "thunk."

Rocketdr-
Thanks for sharing your electric parking break system experiences! It sounds as though it would be beneficial for your service department to diagnose the noise you're referring to. They would be able to let you know whether it's abnormal or whether your Volt is operating as designed. Let the Volt Advisor Team know if we can facilitate the process!

I'm no fan of parking brakes for the intended use (I do like the hand lever in some cars for deliberate drifting and miss it here).

Do we suppose that like most cars, if you never use it, it will rust up and fail? I don't use mine in the Volt.

My Volt does "thunk" once in a while when engaging the parking brake. The brake still seems to hold well enough though. I ignore it as longs it holds the car OK. I might ask my dealer's service department about it the next time I bring it in for service. Not too concerned.

I'm no fan of parking brakes for the intended use (I do like the hand lever in some cars for deliberate drifting and miss it here).

Do we suppose that like most cars, if you never use it, it will rust up and fail? I don't use mine in the Volt.

Um... I guess you don't park on hills. If the car is parked on an incline I always use the parking brake. It can really put a lot of strain on the parking pawl if you don't use the brake. In fact... I once had to help a lady shift her car out of park because there was so much tension on the parking pawl you could not get it to release. I also know a friend who had his car roll down a hill and crash into 4 other cars because we had a small california tremor and it broke the parking paul causing the car to roll away.

I don't use the brake in my garage... But I always use it when parked out in public.

My 2012 had the clunk when engaging the parking break for about a week, then it faded away. From another thread I recall reading that by using the break a bunch of times, it wore down a part that was sticking out a bit too much. I don't think this is a long term issue and it should go away with no negative consequences.

If your parking brake is going "thunk" either when setting it or releasing it, take it to your dealer. It's not supposed to do that, biut it's a fairly common issue with the "parking brake by wire" system used in the Volt (and many other cars, as it turns out).

Thanks to everyone for the responses. I'll get the car checked out next week and will update here when I find out what,if anything, is wrong.