Let It Bleed: General Motors Recall Targets ZF Brakes

let it bleed general motors recall targets zf brakes

General Motors has recalled over 210,000 late-model sedans and crossovers in the U.S. and over 19,000 north of the border after discovering the potential for a braking issue. The automaker blames the issue on rear brake calipers supplied by ZF, which can also be found on vehicles built by Volkswagen, BMW, and Audi.

It all comes down to trapped hydrogen gas in the body of the brake piston, which, when released into the brake fluid, makes for a mushy left pedal and reduced rear brake performance.

GM claims it was first notified of the issue by dealers after certain vehicles failed pre-delivery inspections. On June 14th, days after the automaker opened an investigation into the issue, ZF, which had already notified the German brands about the potential problem, alerted GM. The supplier had failed to properly chrome and temper the pistons, with the potential for small amounts of hydrogen to remain inside the piston bodies.

The automaker claims all of the gas would be released into the brake system within 23 days of assembly, but drivers would notice it after 15 days.

Included in the recall are 2018 and 2019 model year vehicles, among them the Chevrolet Cruze, Equinox, Malibu, Impala, Volt, and Bolt, as well as the GMC Terrain, Cadillac XTS, and Buick LaCrosse.

The obvious solution is for a technician to bleed the brake system and release the gas. GM claims it isn’t aware of any crashes resulting from the issue, and that 306 of the 375 warranty claims it received by the 23rd of August were for vehicles that hadn’t yet been turned over to owners. All of the faulty pistons were installed before July 17, 2018, it added.

[Source: Safercar.gov, via Automotive News] [Image: General Motors]

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  • NeilM NeilM on Sep 13, 2018

    @Ion88: Trust me, if you'd ever bled your own brakes you'd know that's not an option.

  • LuvGermanCars LuvGermanCars on Sep 15, 2018

    2018 Cruze Hatch diesel here and it doesn't seem to have this issue. Probably why it's not under the recall.

  • Inside Looking Out Why EBFlex dominates this EV discussion? Just because he is a Ford expert?
  • Marky S. Very nice article and photos. I am a HUGE Edsel fan. I have always been fascinated with the "Charlie Brown of Cars." Allow me to make a minor correction to add here: the Pacer line was the second-from-bottom rung Edsel, not the entry-level trim. That would be the Edsel Ranger for 1958. It had the widest array of body styles. The Ranger 2-door sedan (with a "B-pillar", not a pillarless hardtop), was priced at $2,484. So, the Ranger and Pacer both used the smaller Ford body. The next two upscale Edsel's were based on the Mercury body, are were: Corsair, and, top-line Citation. Although the 1959 style is my fav. I would love a '58 Edsel Pacer 4-door hardtop sedan!
  • Lou_BC Stupid to kill the 6ft box in the crewcab. That's the most common Canyon/Colorado trim I see. That kills the utility of a small truck. The extended cab was a poor seller so that makes sense. GM should have kept the diesel. It's a decent engine that mates well with the 6 speed. Fuel economy is impressive.
  • Lou_BC High end EV's are selling well. Car companies are taking advantage of that fact. I see quite a few $100k pickups in my travels so why is that ok but $100k EV's are bad? The cynical side of me sees car companies tack on 8k premiums to EV's around the time we see governments up EV credits. Coincidence? No fooking way.
  • EBFlex "I'd add to that right now, demand is higher than supply, so basic business rules say to raise the price."Demand is very low. Supply is even lower. Saying that demand is outstripping supply without providing context is dishonest at best.