A sudden brake system failure on the road can be a frightening experience, especially when it limits your vehicle’s top speed to 43 MPH. This issue often stems from a fault in the brake system, which can have various underlying causes. Understanding these causes and knowing how to troubleshoot them can help you stay safe and get your vehicle back to optimal condition.

Common Causes of Brake System Failure

Piston Compression During Maintenance

One of the most common causes of brake system failure is compressing the brake piston during repair or maintenance. This action confuses the vehicle’s computer, which monitors fluid levels and triggers a fault. To avoid this issue, always disconnect the vehicle’s battery before performing any brake-related work and use appropriate tools to spread the caliper instead of compressing the piston directly.

Pad Wear Sensor Removal

Another common cause of brake system failure is the removal of the brake pad wear sensor during pad replacement. This sensor triggers a warning when the pads are nearing the end of their lifespan, but its removal can lead to premature warning messages, even with new pads installed. Ensure the wear sensor is properly reinstalled and connected to prevent this issue.

Symptoms of Brake System Failure

Loss of Hydraulic Assist

A primary symptom of brake system failure is the loss of hydraulic assist. This makes braking more difficult and requires you to apply more force to the brake pedal. Ignoring this symptom can lead to reduced braking efficiency and potential accidents.

Illuminated Brake Warning Light

Most vehicles have a brake system warning light that illuminates when a fault is detected. This light indicates a potential issue with the brake system and should not be ignored. If you see this light illuminated, it’s important to address the issue promptly.

Clearing the Fault

Brake Service Mode

If you experience a brake system failure, you can clear the fault by putting the vehicle into brake service mode. This involves following specific steps, such as starting the engine, holding the brake pedal, and pressing the electronic parking brake button. Refer to your vehicle’s owner’s manual for detailed instructions on entering brake service mode.

Recalibrating the Brakes

Once the vehicle is in brake service mode, the brakes need to be recalibrated. This process involves pressing and releasing the brake pedal multiple times until a solid light indicates that the recalibration is complete.

Prevention and Consequences

Prevention

To prevent brake system failure, follow these tips:

• Disconnect the battery before performing brake repairs or maintenance.
• Avoid compressing the brake piston directly. Use a caliper spread tool or c-clamp instead.
• Ensure the brake pad wear sensor is properly installed and connected.

Consequences of Ignoring Warnings

Ignoring brake system failure warnings can have severe consequences, including:

• Loss of braking power due to worn pads
• Increased stopping distances
• Potential accidents

FAQ: Brake System Failure and 43 MPH Top Speed Warning

What is the most common cause of brake system failure?

Compressing the brake piston during repair or maintenance can confuse the vehicle’s computer, causing a loss of hydraulic assist and illuminating the brake system warning light.

How can I clear a brake system fault?

To clear the fault, follow these steps:

1. Start the engine and hold down the brake pedal.
2. Hold the electronic parking brake (e-brake) button for 10-15 seconds until a dash light starts flashing.
3. Release the brake pedal and press the e-brake button again.
4. The light should turn solid, indicating that the brakes are recalibrating.

Why am I getting a 43 MPH top speed warning after replacing the brake pads?

Replacing brake pads can trigger a 43 MPH warning because the wear sensor on the old pads has been removed. The sensor alerts drivers when the pads are nearing the end of their lifespan, and its removal can lead to a premature warning even with new pads.

What are the consequences of ignoring the 43 MPH top speed warning?

Ignoring the warning can lead to severe consequences, including:

• Loss of braking power due to worn pads
• Increased stopping distances
• Potential accidents

How can I resolve the 43 MPH top speed warning?

To resolve the issue, check if the wear sensor was removed or not properly installed. Reinstall it securely and ensure that the wiring connected to the sensor is not loose or damaged. If necessary, reset the brake warning system using a diagnostic tool.