Is anyone else experiencing brake issues [failure]?

[firefox2026]

OK I need to enlist anyone who has had brake problems on their Spark EVs.. So they are telling me that the break pressure modulator valve (that was replaced under 2 years ago under warranty was incorrectly installed. Apparently the 4 bolts that connect the electronic brake control module to it were loose. So my extended warranty won't cover faulty workmanship so I am up for the bill. We tried to call GM customer care to complain about it since it was their fault originally. The service manager is telling me their work is only warranted for 1 year so I am out of luck, but then a friend told me they were told it was 2 years so I am confused.

However, I also a bit concerned that they have spec'ed bolts to be tightened to 27 in-pounds which doesn't seem like a lot to begin with. I did find something that said "hand tight" is about 15 to 20 in-pounds but its hard to tell if that depends on the size of the bolt. If that is true it isn't being required to be tightened much past hand tight in the first place. So if the control module is loose it could cause weird codes to come up because it isn't grounded well etc. and air can leak into the brake system and cause problems. I am curious if anyone who has had trouble if they could check and see if those bolts on the brake control module are loose first. I'm going to get a low setting torque wrench and see if I can find a bolt that might be about the same size and get an idea of how tight 27 in-pounds really is.

 

[firefox2026]

I ended up deciding to call my friend who is a mechanical engineer. He says the torque depends on the size of the bolt so I have to figure out how big the bolt is if I can.

 

[SparkE]

I suggest going to the dealership that did the work and talk to a manager. Try to convince him (or her) that the work was not done properly, and that THEY should be responsible for the repairs.

When they say "no way", start talking about twitter and facebook and yelp - they won't want to see you tell a TRUE story about how THEY did bad work and you had to have it fixed again in less than 2 years? That *you* will never take another vehicle to them for service (which is where they make a BOATLOAD of money) and will never purchase a vehicle from them. And you will repeat the post every month for a while.

They might come around and offer to help you with the cost.

 

[firefox2026]

Well that would be a good plan if the work wasn't done in California and I live in Colorado..

Also the dealership in Colorado did offer a reduce bill for the repairs, but I think GM should have done something. I will be making some noise on the internet about this if they don't.

 

[firefox2026]

I keep forgetting I wanted to post an update on this. So the problem repeated itself about 6 months after I got it fixed at the dealer. I had moved to a different suburb of Denver so I ended up taking it to a different dealer. These guys knew what they were doing and got it fixed finally. I have had no problems since then. They also worked with my aftermarket insurance. So they ended up having to replace the controller and the electronic valve modulator. They got GM to pay for the controller and the insurance paid for the new modulator and most of the labor. So it still cost me about $600 but that was much better than the overall 2.5k price tag. I got the impression from the manager that they maybe knew there was an issue with the controller (maybe older ones), but he didn't want to say it was GMs problem. Also they had a lot of trouble getting a a good valve modulator due to the protective packaging of the part being substandard. Which also make me worry that maybe some shops are putting in broken valve modulators. In any case if you keep getting this sort of think happening repeatedly I would suspect the controller and I would try to get GM to pay for it if you can and make sure you get a good valve modulator if you have to replace it.

 

[twinsemi]

Yes, I know this is an old thread, but not an insignificant one.
My story occurred a few years ago and was covered completely under warranty, with loaner cars provided at no charge by the dealer. I think they were going through a learning curve at the time. Hopefully they are better now. But I don't see the knowledge widely discussed online, so here it goes.

Not to bury the lead, have you cleaned your ABS sensors at all four wheels?

My brakes died, as in no power assist, and I drove on using all of my leg strength that I could muster. I have and learned to drive cars with manual brakes. This was way beyond that or even unassisted power brakes on IC cars. The dealer (that's where I drove to) spent 6 weeks to get the car back on the road. They kept telling me that the brake module was the problem and first it was on back order, and then the replacement was bad and then they reinstalled it incorrectly. So I had lots of time to do some internet research. What I found was that the TRW brake module was used on other cars besides the Spark EV. Chevy Tahoe Hybrid for one. A guy on one of those threads had been having similar problems and finally had success by cleaning or replacing the ABS sensors at two of his wheels. Because the SparkEV uses the electro-hydraulic module for ALL of our braking, if your ABS sensors get dirty and send bad data to the brake controller, the system just stops working rather than disabling ABS and traction control, like in a typical IC car.

So when I told the dealer that they needed to look at the ABS sensors, my car was magically fixed two days later. No, they did not confirm that the sensors were the problem, because if they had, they would be out all of the warranty costs that they wanted to recoup from Chevy. But it would be too much of a coincidence not to be the case.

So there you have my 2cents.

Happy electric motoring.

 

[ZNuts]

Thanks, good to know about ABS.

I do notice once a while if I go over a bump or a dip the brake will disengage for a brief second and I suspect that has to do with how ABS sense a locked wheel. So far it hasn't become a major issue.