GM recalls 3.5M pickups, SUVs to fix brake defect
The brake-assist pump may lose vacuum over time, increasing stopping distances.
General Motors has issued a large recall for nearly 3.5 million pickups and SUVs to fix a brake defect.
The campaign affects certain 2015-2017 Cadillac Escalade; 2014-2018 Chevrolet Silverado and GMC Sierra; 2015-2018 Chevrolet Suburban, Tahoe, and GMC Yukon vehicles.
The vacuum level created by the brake-assist pump may drop over time, eventually increasing braking effort and extending the distance required to stop the vehicle.
"The condition is more prevalent at low speed when softly applying the brakes," GM's recall documents note.
The issue is said to involve debris, such as oil sludge, that can accumulate on a filter screen and restrict flow to the vacuum pump. GM says that failure to follow recommended oil-change intervals can contribute to the problem.
The vehicles are equipped with a secondary hydraulic brake-assist system, which was originally calibrated to activate at higher speeds. The recall fix centers around revised control programming that changes how the system uses the hydraulic brake boost function when the vacuum assist is depleted.
The company had initially addressed the defect via an extended warranty program, until the NHTSA launched an investigation that eventually led to a formal recall.