EPB "Clunks" on Engagement

[BILL GERTH]

While waiting for parts to come in to replace my EPB cables, the "clunking" sound totally disappeared. It has been flawless for well over a week and I use the EPB every time I park my Volt. The parts did come in to my dealer and I had a service appointment scheduled for yesterday, 12/29/2011, but, upon consultation with the dealer service techs, I elected to give things another couple of weeks for evaluation. They have agreed to hold onto the parts until then. I'm just unwilling to force a warranty repair of something that is not malfunctioning at this point and run the risk of unintended consequences.

My Volt is still "clunk free"

My best guess, after crawling under the car and looking at the service drawings, is that one of the swaged cable-end fittings had a rough spot on it causing it to grab and then release suddenly at the end of the engagement cycle. With continued usage, the rough spot got worn smooth and now there's no "clunking." Just a guess.

Stay tuned :-)) BILL

My Volt is still "clunk free" after over 9,000 miles after it "fixed" itself. I use the EPB many times per day.

[Cheryl B]

Glad to hear your update Bill. If nothing else...perhaps it will fix itself before dealership figures it out. I realize buying "new technology" in the first couple years means we are guinea pigs getting to work out the kinks...but the Volt at least makes it FUN!!
Cheryl B
Lansing, MI

[BILL GERTH]

Glad to hear your update Bill. If nothing else...perhaps it will fix itself before dealership figures it out. I realize buying "new technology" in the first couple years means we are guinea pigs getting to work out the kinks...but the Volt at least makes it FUN!!
Cheryl B
Lansing, MI

Cheryl,

Actually, I'm told that the EPB system on the Volt is similar, if not identical, to other GM cars so it is not new technology with the Volt. When I first reported the problem shortly after I bought the car, there were very few others who had experienced this. From this, I conclude that it was just a rough spot on the cable assembly that "wore in" and nothing in the design. The EPB seems to hold well, even when parking on steep slopes.

Glad you enjoy your Volt! In my opinion, the concept is really excellent. I'm still smiling about the gas I HAVEN'T bought!

[SocalGary]

After appoximately 6,000 miles over nearly 3 months, I started hearing the CLUNK at the end of the Brake engagement. Happens every time, but if I release the brake right away and re-engage it to "test" the brake it does not happen. I will monitor it and take it to a dealer soon if it does not fix itself like it has for some of the others.

Love my Volt !

Gary

[DCFusor]

The Volt has a parking brake? </humor>

I've never even tried mine once, even on hills, and I live in the mountains. Every parking brake I've ever seen is a liability unless you can grab a handle to use it to get into a deliberate spin. They all slip, so the parking pawl always winds up with all the force anyway, and they jam on, or off, if not used enough (rust), and never seem to work when you need one because the normal brakes failed - never strong enough - if you do, it's an emergency brake indeed!

[yoyodyn]

Ok, I have had a similar clunk when engaging the EPB. I figured it was normal since it has happened since day one. However, it's changed a little now that the clunk may not happen as the brake is being engaged, but a few seconds afterwards usually as I am walking away from the car. It's not every time. My 7500 tire rotation is coming up, so I am planning to have the dealer look at everything then. (Battery enforcement, new EVSE, airbag, tire rotation, etc.) So I will add this to the list.

Trevor, if this issue has been happening, is there a memo/tech doc that I could point my dealer too if they don't know what I am talking about? (It will be at least two weeks before I go in)

[NoRegrets78]

Just started getting this clunk. Trip number 5 to the dealer coming up.

I'm really starting to get annoyed at these issues that take full days at the dealer to fix. Unacceptable for a car at this price point.

[AdamK]

Same here, just started at 3,500 miles. Doesn't do it on every application though. Have an appointment on Friday at the dealership. I feel the same as some of you - don't really want them poking around if it will go away and there is a chance they screw something else up.

[Chevrolet Customer Svc]

Ok, I have had a similar clunk when engaging the EPB. I figured it was normal since it has happened since day one. However, it's changed a little now that the clunk may not happen as the brake is being engaged, but a few seconds afterwards usually as I am walking away from the car. It's not every time. My 7500 tire rotation is coming up, so I am planning to have the dealer look at everything then. (Battery enforcement, new EVSE, airbag, tire rotation, etc.) So I will add this to the list.

Trevor, if this issue has been happening, is there a memo/tech doc that I could point my dealer too if they don't know what I am talking about? (It will be at least two weeks before I go in)

Evening Yoyodyn,
Trevor is no longer with us, I will be taking over for him. What your describing sounds like normal operation. At times the Anti-lock brakes heats up the Actuator and when it cools down it may result in a popping/clunking noise. Also when disengaging the parking brake there maybe a clunking sound. This too is normal and more noticeable due to the silence of the Volt. A traditional ICE vehicle would normally cover up this sound. If you still feel that it is not the norm feel free to have your dealership look at it. I would like to save everyone a trip if possible.
Cheers!
-Ian Chevrolet Volt Customer Service

[AdamK]

Back from the dealership today - there is a service bulletin and the tech installed new rubber washers somewhere in the parking brake assembly. Appears to have fixed the problem so far. Take it in and ask about the bulletin if you need it.