General Motors is voluntarily recalling certain 2014-2018 model year Cadillac Escalade, Chevrolet Silverado, Chevrolet Suburban, Chevrolet Tahoe, GMC Sierra, and GMC Yukon vehicles for a condition related to increased brake pedal effort, in rare circumstances, these vehicles may have a condition in which the engine-mounted mechanical vacuum pump output may decrease over time, decreasing the amount of vacuum/power brake assist.