On Sep. 6, General Motors notified dealers they will need to resolve an issue with a vacuum brake assist pump that makes it more difficult to engage the braking system and increases the risk for a crash. GM identified six models potentially afflicted with the defect between 2014 and 2018, totaling 3,456,111 vehicles in all. This includes two pickups—the Chevrolet Silverado (2014-2018) and GMC Sierra—and four SUVs, including the Cadillac Escalade (2015-2017), Chevrolet Suburban, Chevrolet Tahoe and GMC Yukon.
GM told CNN that the problem has resulted in 113 accidents and 13 non-fatal injuries.
The problem appears to stem from excessive debris and sludge build-up on the vacuum pump filter screen as the engine oil lubricates it. This leads to a drop in vacuum and may necessitate more pressure applied to the brake pedal, create a “hard brake pedal,” and increase the time it takes to stop. Trucks and SUVs overdue for an oil change may be at a higher risk. Recalibrating the electronic brake control module to recognize lack of vacuum assist and activate hydraulic assist resolves the issue, GM says.
On the safety recall report, it’s noted that: “At all times, the brakes remain functional and exceed the requirements of S7.11 of Federal Motor Vehicle Safety Standard (FMVSS) No. 135, ‘Light Vehicle Brake Systems.’”
The NHTSA opened the investigation last November and the Office of Defects Investigation received 111 hard brake reports from the various affected trucks and SUVs. Nine of the vehicles were involved in low-speed collisions, where it looks like the issue is more prevalent. The ABS system supplies supplemental hydraulic brake assist if vacuum drops, though at a lower level under low speeds.
GM is responsible for notifying owners, but you can also visit https://www.nhtsa.gov/recalls and enter your VIN to see if your vehicle needs to be brought in and repaired. The NHTSA Safety Issue ID is 19V645000. The dealership will reprogram Electronic Brake Control Module to fix the problem.