General Motors has issued a recall for several 2018-2019 models due to a brake problem that could lead to a collision.
Models with the issue are said to have defective brake pistons. According to GM (via GM Authority), the supplier (ZF Group) that provides the specific brake parts didn't "properly chrome and temper the brake pistons," which may lead to hydrogen gas being released into the brake piston and then trapped. This could cause the driver to feel "spongy" braking and rear-braking power may be reduced.
While GM is not reporting any incidents caused by the problem, it's noted that as the rear-brake performance lessens, a driver could lose control of the vehicle. Some 230,000 vehicles in the U.S. and Canada are impacted by the problem, including the 2018 and 2019 Chevrolet Bolt EV, as well as the 2018 and 2019 Chevrolet Volt.
To find out if your car is affected, visit my.gm.com/recalls. Once you enter your VIN, you'll be able to find out if your car requires service. Fortunately, it appears that the fix is simple. It just involves bleeding the rear brakes to get rid of the trapped gas.
Interestingly, ZF Group has already been looking into a similar issue with cars from other manufacturers. However, the supplier didn't notify GM right away or include the automaker in its recent report of vehicles with the particular calipers related to the recall.
Source: GM Authority
CHEVROLET BOLT EV
Gallery: General Motors Brake Recall Hits Chevy Volt, Bolt Too