This bulletin describes the procedure to properly bleed the brakes on Sonata HEV/PHEV (LF) and Ioniq EV/HEV/PHEV (AE) vehicles. This procedure applies when any air is introduced into the Active Hydraulic Boost (AHB) system, which consists of the pressure supply unit (PSU), and the integrated brake actuation unit (IBAU). Improper bleeding of the brake system can result in the presence of air, which may reduce braking effectiveness.
