Brake Fluid Replacement for Hybrid Brake Systems

The braking system in a hybrid vehicle is more complex than in a conventional car. In addition to the hydraulic brake system, hybrids use an electronic brake control module and regenerative braking that assists in slowing the vehicle. Because of this design, a simple manual brake bleed is not always the correct procedure. On many Toyota and Lexus hybrid models the manufacturer provides a service function called Air Bleeding through the Techstream diagnostic system, which sequentially operates the valves and allows the brake circuits to be properly bled. In some factory procedures a pressure bleeder or dedicated service station is also used to push fresh brake fluid through the system while the electronic valves are activated. That is why brake fluid replacement on a hybrid vehicle requires a different approach. At our shop we use professional equipment and follow the correct service procedures for hybrid braking systems. Many vehicle owners postpone this service because of the cost, but timely brake fluid replacement can prevent much more expensive repairs later. Electronic ABS modules and hybrid brake control units are extremely sensitive to the condition of the brake fluid, and if the fluid becomes contaminated or absorbs moisture it can damage these components. Replacing those units can cost thousands of dollars.