Possible Causes of Drum Brakes Failing to Function Properly

Understanding Drum Brakes Not Working Causes, Symptoms, and Solutions

Drum brakes are a crucial component of the braking system in many vehicles, especially in older models and in some trucks and SUVs. Unlike disc brakes, which are more commonly used in newer vehicles, drum brakes function by using friction generated by brake shoes pressing against the inner surface of a rotating drum. While they are effective and cost-efficient, drum brakes can experience various issues that may lead to them not functioning properly. Understanding the causes, symptoms, and solutions to drum brake malfunctions is essential for every vehicle owner.

Common Causes of Drum Brake Failure

1. Wear and Tear Over time, the components of drum brakes, including the brake shoes, springs, and drums themselves, can wear down. The friction material on the brake shoes can become too thin, reducing their ability to generate the necessary friction to stop the vehicle.

2. Moisture and Contamination Drum brakes are more susceptible to moisture ingress compared to disc brakes. Water, mud, or road salt can accumulate inside the drum, leading to corrosion or contamination. This can significantly impair their performance, causing issues such as reduced braking efficiency or brake fading.

3. Adjustment Issues Drum brakes require periodic adjustments to maintain optimal performance. If the adjustment is not properly done, the brake shoes may not contact the drum effectively, leading to longer stopping distances and a spongy brake feel.

4. Spring or Hardware Failures The small components that hold the drum brake system together, including springs, retainers, and adjusters, can fail over time. A broken spring can prevent the brake shoes from returning to their parked position, leading to dragging brakes and increased wear.

5. Brake Fluid Leaks While drum brakes primarily rely on mechanical action for braking, they may also use hydraulic systems in some setups. A leak in the brake lines or master cylinder can lead to loss of brake fluid, ultimately resulting in brake failure.

Symptoms of Drum Brake Failure

Recognizing the signs of failing drum brakes is crucial for ensuring your vehicle remains safe on the road. Some common symptoms include

- Reduced Braking Power If you notice that your braking distance has increased, it could indicate that the drum brakes are not functioning correctly. This could be due to worn-out brake shoes or insufficient adjustment.

- Unusual Noises Grinding, squeaking, or squealing noises when applying the brakes can indicate that the brake shoes are worn down to the metal or that debris is lodged between the drum and shoes.

- Vibration or Pulsation Feeling vibrations or pulsations through the brake pedal while braking may suggest that the drum is warped or out of round, which can occur from excessive heat or wear.

- Pulling to One Side If the vehicle pulls to one side when braking, it may indicate that one of the drum brakes is not working effectively, potentially due to an issue with the brake shoes or adjuster.

Solutions for Drum Brake Malfunctions

If you suspect that your drum brakes are not working properly, it is crucial to address the issue immediately. Here are some steps you can take

1. Inspection Begin with a thorough inspection of the braking system. Check the condition of the brake shoes, drum, and all related hardware. Look for signs of wear, moisture, or corrosion.

2. Replace Worn Components If any parts are found to be worn beyond their limits, they should be replaced. This includes brake shoes, drums, and any springs or hardware.

3. Proper Adjustment Ensure that the drum brakes are correctly adjusted. Many vehicles have a self-adjusting mechanism, but manual adjustments may be necessary in some cases.

4. Clean the System Remove any contaminants from the drum and shoes. Cleaning surfaces can help improve contact and effectiveness.

5. Professional Assistance If you are unsure about diagnosing or fixing drum brake issues yourself, it’s advisable to seek help from a professional mechanic. They can provide a comprehensive evaluation and ensure that your braking system is safe and effective.

In conclusion, while drum brakes can be effective, it is essential to be aware of the signs of failure and the potential causes. Regular maintenance and prompt attention to any issues will ensure a safer driving experience.