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How to Determine If The Brake Actuator in Your Lexus is Failing

by Mechanics Direct August 21, 2019

For some time now there have been issues with brake actuators in several Lexus models failing. Not only does this mean that the brakes fail to perform as expected, but it can happen at seemingly random times, even at high speeds. In this article, we will go through some of the ways that you can recognize that your vehicle may be experiencing brake actuator trouble and hopefully help you prevent failure at a critical time.

What is a brake actuator?

It is important to understand what a brake actuator is in order to see how malfunction and failure can have some serious consequences. The brake actuator is basically a relay system that controls the hydraulics of your brakes in tandem with the skid control ECU. It includes the pump motor, linear solenoid valve, accumulator, wheel cylinder, and master cylinder pressure sensors.

When you apply pressure to the brake pedal, the fluid in the brake lines cause the actuator to push the brake shoes outward against the brake drum. In disc brakes, the caliper is squeezed into the brake pads. So, it is easy to see how malfunction or failure in the brake actuator can cause some serious issues.

Brake Actuator Failure Warning Signs

Hissing or Whistling Sound

The first sign that you may notice is a slight hissing or whistling sound. Since the brake actuator is a closed pressurized system, there should not be any apparent sounds if it is operating normally. This is a result of a leak in the pressurized system allowing the necessary compression to decrease over time. Pay attention any time you apply pressure to the brake. If the actuator is losing pressure, this can be noticeable when applying the brake to start the vehicle in addition to regular braking while driving. Additionally, if you use your parking brake regularly, then you may notice the slight sound when setting the parking brake as well.

Increase in Pedal Pressure

Under normal conditions, your brake pedal should operate smoothly with no need for much force to depress the pedal. As the actuator begins to fail, you may notice that the pedal is harder to press and seems to require significantly more force to completely depress.

Delay in Braking Response

As the pressure in the brake system decreases the amount of time that it takes for your car to slow down and stop may be delayed. This can occur at the same time as the increase in pedal pressure.

Popping/Clicking Sound

There have been various loud sounds reported to occur immediately preceding brake actuator failure. Though the descriptions of the sound may vary, they are all loud and consistent. The loud sounds likely result from the pressure leaking rapidly from the brake system, as the brake actuator fails to regulate the pressure.

Sudden Brake Failure

The worst and eventual result of brake actuator failure causes a sudden failure in the braking system. Since the brake actuator is responsible for both immediate braking and the parking brake, this can occur at nearly any time. Owners have reported the sudden failure at many different speeds, including braking to slow a vehicle as well as intentional stop braking. Failure, while parked with the parking brake engaged, has also been reported to result in diagnosing brake actuator failure.

Warning Lights

Most vehicles are now equipped with several warning lights built into the dash in order to alert the driver. Since every model is different, it is important to recognize the warning lights that may signal brake actuator trouble. Some warning messages that have been reported to in connection to brake actuator failure include:

  • Brake malfunction
  • Check ABS
  • Check VSC
  • Check Brake System
  • Do not drive vehicle due to system failure, contact dealer immediately
  • Stop the vehicle and contact the dealer
  • Check vehicle system, stop the vehicle in a safe place immediately
  • Please stop and call the dealer immediately

What to Do When Brake Actuator Failure Occurs

Obviously, if the failure occurs when you are driving your vehicle, your primary concern will be to stop safely. After you are safely stopped, contact Mechanics Direct, and we will be there to help you confirm the brake actuator failure and provide top quality replacement services. There have been several recalls related to this issue. Mechanics Direct can assist you in determining if your model is subject to recall and walk you through the process if necessary.

How Mechanics Direct Can Help

Mechanics Direct provides top-notch service from ASE Master Certified Technicians in a unique one-on-one service. Our goal is to get you back on the road as quickly as we can by making sure that your vehicle is operating at top performance and safety. Direct lines of communication between you and your mechanic will ensure that you are always up to date on the status of your vehicle and there are no unnecessary surprises. Mechanics Direct offers over 23 years of service excellence. Additionally, we’re located conveniently to North Chelmsford, Chelmsford, Dracut, Tyngsborough, Westford, and Lowell, Massachusetts. If you think that your brake actuator may be malfunctioning, please give us a call today. Let us help before your brakes fail completely.

*Lexus Car image credit goes to:kurmyshov.